[This thread continues a discussion that began on the HHPA group.]
Tad,
I've looked at your single-point release and have a general understanding of how it works, but while it looks like a great design I certainly wouldn't trust myself to make one, so I'm going to have to rely on something I can buy already made.
I've used a Lookout spinnaker type as a primary and a Bailey barrel type as a secondary since I began aerotowing. I've been happy with the primary for the most part (never used the secondary) until recently. I released once on my recent Lookout trip (the rest of my flights were foot launched)...here's the vid of it (password = 'red'): http://vimeo.com/17472603
Lately for unknown reasons the release has been requiring more effort to activate under tension (it always seems to release fine on the ground). Usually it activates on the second pull, but that time it took four pulls. Not the kind of thing I want to deal with in an emergency. Inspecting it, it looks the same as it always has to me.
I've seen Lookout's new purpose-built design and I liked what I saw. They were out of stock when I was there, however. You've tested this release, correct? What do you think of it? Is there a better off-the-shelf two-point release on the market?
As for the secondary, I never knew about the issues with Bailey releases until you pointed them out. Are there any straight-pin barrel releases on the market?
Regarding platform towing...
Tad Eareckson wrote:I would not platform launch with conventional equipment.
Well, is there any unconventional equipment you'd platform launch with? Can your single-point release be adapted for platform launching? Do you know if there are any commercially available mouth releases that would work for platform launching? I want something better than what I'm using.
A few responses...
Tad Eareckson wrote:But with a little effort the pictures should be pretty self explanatory - especially for someone as smart as you are.
No one is smart in every way. When it comes to anything mechanical I'm a complete idiot.
Tad Eareckson wrote:Some day I'd like to get some people organized and hit Wills Wing with a petition to make this stuff available.
I'd sign it. I think you'd have much better odds if their shop was in Florida, however.
Tad Eareckson wrote:We have seen time and time again that release failures can kill you as quickly and completely as a bullet in the head. So what you're saying is that you're willing to spin the cylinder every time you tow.
If I had to be 100% sure about everything before I flew, I would never fly. I can't even be 100% sure about anything. We take many risks when we fly...we minimize them as much as possible, but they'll always be present to some extent. Did you yourself not indicate that you foot launch without being 100% sure you're hooked in?
I had a lot of confidence in my release until recently. I don't know why I'm having trouble with it, and this kind of thing is why I'll always have a certain degree of distrust for anything mechanical.
Tad Eareckson wrote:And I keep asking people of a release EVER failing for a reason that wouldn't have been blindingly obvious to a halfway intelligent ten year old kid. And I've NEVER gotten a straight answer to that one. So what was the reason THIS release failed?
It was my release (Lookout spinnaker type). I wasn't very experienced at the time and only had a few tows with it. It looked fine to me but I had it inspected afterwards by the shop and they pointed out a manufacturing defect of some kind...a metal cylinder wasn't shaped correctly or something. I can't remember if they replaced or repaired it, but I didn't have any trouble afterwards until recently. Sorry I can't be more specific about the problem, but it certainly wasn't obvious to me at the time.
...and have a general understanding of how it works, but while it looks like a great design I certainly wouldn't trust myself to make one, so I'm going to have to rely on something I can buy already made.
'Cause you think there's some possibility you could do worse than the crap you're using now? You worry way too much - about the wrong things.
I've used a Lookout spinnaker type as a primary and a Bailey barrel type as a secondary since I began aerotowing.
Glad to hear you referring to it as a "secondary" rather than a "backup". If your upper anchor point is a bit fore of the hang point - which, for the Sport 2, Wills Wing recommends it to be - using a secondary as a backup can put you in instant Len Smith mode, i.e. with your life dependent upon a clean parachute deployment.
I've been happy with the primary for the most part (never used the secondary) until recently.
During the Dragonfly promo tour in the summer of 1991 panic snap based releases were being used. They were secured to the carabiner and your hand went into a loop at the bottom end of the cable. The secondary was on the tug. Cheap, safe, and effective.
I wanted to roll my own but couldn't find anything at the horse shops that wasn't unappealingly clunky. One day at Annapolis Performance Sailing I found myself staring at a 2673 Wichard Quick Release (spinnaker) Shackle. It was beautiful and elegant and I played with it for a while. I wasn't real happy about the notch and the fact that the gate increased in girth from the pivot point to the end but it seemed to work OK anyway and I forked over fifty bucks and took it home with the intent of turning it into the coolest aerotow release ever.
I put it in the air on 1994/09/04 thinking I had scored a first. Subsequently found out from Campbell Bowen that the Dragonfly people had started using them right after the conclusion of the tour. Then, early this year, found a reference from Australia in the 1983/09 issue of the Skyting newsletter.
When I first saw the Wallaby release the next year I thought, "What a dangerous draggy piece of junk." Bicycle brake lever often mounted on the downtube, often incapable of sharing the basetube with a wheel on the same side. Then Quest figured out how to butcher the already marginal mechanical advantage of the core mechanism.
There has be something in central Florida's water that destroys all the brain cells associated with the understanding of the second class lever. I had always assumed everyone who had had an ancestor who had figured out how to use a stick to roll a heavy log would've been good to go.
Or just look at my avatar and think about it for a couple of seconds.
Anyway...
The spinnaker shackle is not designed to release a piece of string or small diameter line under anything up to a 300 pound load in a life or death scenario. It's designed to HOLD a Safe Working Load of 1100 kilograms (nearly one and a quarter tons) transmitted by a heavy rope and release ain't gonna happen until all but a tiny fraction of that tension has been relieved.
It's not designed to be triggered with a cable. It's designed to be triggered with a leechline lanyard routed over the latch for a two to one actuation mechanical advantage.
And it's not designed to not chew up the loops of 130 pound Greenspot all the idiots use for weak links.
I configured mine for lanyard actuation with two to one mechanical advantage and, through the duration of the period when I was one of the idiots using 130 Greenspot weak links, sized the loops for the minimum to clear the gate. Never had a failure but I would routinely feel a little hesitation whenever I slackened the towline prior to release.
But I'd hear about a cable actuated release failure at Ridgely about once every weekend. One of my happiest memories... I warned visiting pilot Jim Lawrence what pieces of crap these things were but he decided to go with a Quest anyway. Sunny took one out of the plastic bag for him, attempted to demonstrate its function, and was unable to get it to open. (No problem, here's another one. These things really DO work at least three quarters of the time.)
I released once on my recent Lookout trip...
And you had one other tow flight - I'm guessing immediately prior - which topped out with a weak link blow in the course of a normal, entirely appropriate control input necessary to follow the tug in smooth air.
Lately for unknown reasons the release has been requiring more effort to activate under tension (it always seems to release fine on the ground).
Yeah, everything always works fine on the ground - until you start loading it up to some substantial fraction of what will normally feel in flight or some tiny fraction of what it CAN feel in flight. George Worthington's Wanderer motorglider did just fine on the ground.
Ralph Sickinger - 2000/08/26 22:18:20 UTC
Under sled conditions (2000/08/26 18:00 EDT), I decided to borrow Brian Vant-Hull's glider instead of setting up my own, since we both fly the same type of glider. Brian's release is a different style, but I tested it twice during preflight to make sure I was familiar with it. After towing to altitude, Sunny waved me off; I pulled on the release (hard), but nothing happened! After the second failed attempt to release, I thought about releasing from the secondary, but before I could move my hand the tug stalled and started to fall; Sunny had no choice but to gun the engine in attempt to regain flying speed, but this resulted in a sudden and severe pull on the harness and glider; I was only able to pull on the release again, while simultaneously praying for the weak link to break. The release finally opened, and I was free of the tug.
Brian Vant-Hull - 2000/08/28 22:49:13 UTC
I purchased my release (the one Ralph used) at Lookout Mountain over a year ago, but never had any problems until the Ridgely Fly-In, where the same thing happened. I pulled three or four times on the release, then finally went to the secondary, by which time I was high above the tug and Sunny (is there a connection here?) was frantically waving me off.
You didn't use it as a secondary - you used it as a backup. What was your plan gonna be if the bridle had failed to clear the tow ring? Go for your parachute?
I've found it to fail this way once more since then, then on Ralph's flight, for about one time in ten.
Usually it activates on the second pull...
And that wasn't scaring the crap out of you? How long would you continue driving a car whose brakes usually kicked in after the second stomp on the pedal?
...but that time it took four pulls.
And, as best as I could tell, two seconds. Smooth air, normal, regularly scheduled release - under 75 pounds on the mechanism. And if you're closing on the ground at thirty miles per hour, that two seconds has just eaten up 44 feet. That can make a real big difference in how the rest of the day's gonna go.
Not the kind of thing I want to deal with in an emergency.
Do ya think?
Inspecting it, it looks the same as it always has to me.
Yep. Shoddy slap-on junk.
You're using an inappropriate core mechanism, halving the designed actuation mechanical advantage, and introducing the binding issues inherent in a couple of major bends in cable and housing. In REAL aviation this kinda crap would never make it into the air at all - let alone after this kind of record.
After a bit over two decades of Dragonfly towing, two consecutive flights - BOTH with equipment malfunctions which HAVE killed people in less benign circumstances.
In the early days of towing, just like the early days of hang gliding, there was a learning curve. Unfortunately, accidents happen, despite our efforts. We try to learn from them and improve our techniques and equipment as a result, and I believe we've been very sucessful in both.
Bottom line, hang gliding has certain risks. You need to evaluate those risks and determine if you feel that they are worth it for you. If not, don't participate. I have every confidence that the folks who I know personally that are towing are doing it safely and contientiously.
In industry, they called that THE NORMALIZATION OF DEVIANCE. In other words, if something (wrong) happens often enough, we begin to treat is as NORMAL and go on with our lives.
I've seen Lookout's new purpose-built design and I liked what I saw.
Yeah. Built for the purpose of slapping onto a glider that itself wasn't purpose-built.
"Congratulations on the purchase of your new Prius, Mr. C. If you decide down the road a few weeks that you'd like brakes there are a couple of shops in the area that have some pretty good options. But whatever you get we recommend that you replace the velcro once every two years."
You've tested this release, correct?
Not the way it really should be tested. But I loaded it up to about 375 pounds and found that it blew with a surprisingly light pull. (Interestingly, after having been going up for some months prior, that was the first time it had ever been bench tested. I also was given by Matt the same honor with respect to the weak links he'd been issuing for the past twenty years.)
What do you think of it?
I despise it - for the same reason I despise the Aussie Method of "guaranteeing" that you're hooked in on launch.
It's something that's gonna work really well for most people in most circumstances most of the time. So it's gonna flood the culture and serve as an insurmountable impediment to doing things right.
Why bother doing - or looking for - a hook-in check JUST PRIOR TO LAUNCH when you - or the people you're launching - "never" enter the harness unless it's connected to the glider?
Why should Wills Wing offer a built-in aerotow release system as beautifully engineered as their VG systems after everybody and his dog have just forked out $140 - plus shipping and handling - for the latest 99 percent reliable, velcroed-on piece of crap from Lookout?
Also, the Aussie Method becomes EXTREMELY dangerous to its cult members when convenience, safety, and common sense issues start kicking in.
Likewise, while two point towing is safer than one point because you can command the entire speed range for which the glider was certified, nobody wants all that crap in the airflow. So someone who would be more than happy to have the safety of two point towing if he could get it in a clean built-in system will go one point for the performance advantage.
And comp pilots get penalized for flying with wheels so they don't.
Is there a better off-the-shelf two-point release on the market?
No.
Are there any straight-pin barrel releases on the market?
It's been alleged that Steve Wendt is selling them but his Web site is showing curved.
I can set you up with barrel releases. My stuff is gonna be the best regardless.
Regarding platform towing...
The thing that's always scared me shitless about platform towing was John Woiwode - 2005/07/07.
I accompanied him to the Nationals at the Sequatchie Valley, mid April 1988. He was a top notch competitor, I was free flying. Very personable, likable guy. (Also helped fish him out of the tree where he parked a demo glider at Hyner View, Pennsylvania a couple of years later. Check out the LZ. Kinda hard to miss that one, wouldn't ya think?)
He was horribly mangled in a career ender in Wyoming. I always knew that he could've done better by releasing as soon as possible when he got an indication of a line dig - but I was never real sure that I'd have done any better in the same circumstances.
I Just recently found my way back to "The Oz Report," and started a new account.
I was reading about an old accident report about "John Woiwode's Lockout"
From what Ken and John report it seems likely to me what two really big factors could well have contributed the most to the chain of events that led to the lockout.
Ken reported:
JW's glider was an Aeros Combat 14 Meter with minor modification to enhance turning (slightly shortened flying wires).
and----
---The specific cause and methods that could have prevented the accident are not known.
John reported:
"At about 30', I drifted lightly to the right with a soft south push. It was a gentle deviation, so I applied a correction that stopped the right drift and eventually brought me back in line with the trailer. I was still climbing ok as the line paid out. It was at this time, lined up square with the road and climbing slowly, that I felt a distinct pull on the glider from the tow line, and a rapid acceleration. My fleeting thought at that moment was that I was ok for a bit because the glider was straight and in line with the tow vehicle. I noted that I was catching up to the vehicle/trailer."
Here is my take:
The shortening of the flying wires will make a glider more easily rolled plus the adverse yaw will become a bigger factor. (Like towing a K-2 glider with its stock shorter designed flying wires.)
If there were a slight left crosswind as JW indicates and the glider is brought back in line behind the truck, The glider will now be closer to the poor handling and lock out area to the left/south than it will be to the poor handling and lock out area to the right/north of the glider.
It has been my experience that as the line tension increases the sweet spot that a pilot wants to be centered in while towing narrows. The poor handling and lock out areas to the left and right of the glider move in closer.
The added line tension (Possibly due to line dig on the winch spool.) would exacerbate the adverse yaw at the higher airspeed. [--"I felt a distinct pull on the glider from the tow line, and a rapid acceleration."--]
The next thing, since the lockout was to the left, would support my theory that JW was left of center but still within the sweet spot. The center of the sweet spot would have been slightly north/right of the tow vehicle due to the left crosswind and not directly behind the tow vehicle. As JW's airspeed increased the sweet spot narrowed to the point that JW was now entering lock out to the left. In other words the left area of the sweet spot moved over to meet with JW as it narrowed due to more line tension.
KC summery, "The specific cause and methods that could have prevented the accident are not known." Seems accurate with the information at hand.
Steps that I would take in an effort to do something that may prevent an event like this from happening again with would be:
1. While towing any double surface glider with anhedral (downward sloping wings.) designed or modified for ease of roll use a vertical stabilizer to correct for the inherent adverse yaw at high speed in particular.
2.With a crosswind component make sure pilots understand that they should not assume that they be directly behind the tow vehicle for the safest tow.
There is a start.
Maybe some refining on some of the following suggestions would be of help.
3.Don't tow up so fast or with so much line tension that you reduce the size of your sweet spot to a critical state.(This could include installing line tension hydraulic compensator linkage.)
4.If possible arrange the release so that it doesn't require the pilots hand to be removed from the control bar. That's a tough one.(Remember with one hand off of the control bar your control authority drop more that 50%. It will be down to maybe 5%.)
5.For tow up have the pilot be on constant transmit. (Not for students.)
I CAN'T BELIEVE I WAS SO STUPID AS TO MISS THAT!!! I've read that report a hundred times and it was like it was invisible. I think I was just so awed by John's competition, XC, and experience record that it wasn't registering that he did something that clueless.
And, although that wouldn't have helped a whole lot, I'm not talking about tweaking the sidewires. If the glider hadn't been doing weird, unpredictable things in free flight there's absolutely no reason it for it to have been doing them using a platform tow bridle. And, as Roy Messing demonstrated at Whitewater on 2009/08/31, a factory fresh Falcon 3 195 is more than capable of locking out in dead air on a fixed length towline and slamming the pilot in fatally in the blink of an eye.
HE CRABBED HIS GLIDER TO STAY BEHIND THE TRUCK IN A CROSSWIND!
Donnell Hewett damn near killed himself pulling that stunt - in combination with his suicide release - on 1982/10/23 on the fourth flight of his brand new UP Gemini 164.
A bit over two years before the last guy I ever signed off on a rating (Frank Sauber - Two) got killed by a scooter tow lockout I was fighting him over an article he was submitting to the local newsletter on towing. (No Frank. You don't stay behind the vehicle, you don't "keep the glider heading parallel to the vehicle" - you let the glider POINT TO the vehicle. I remember him going to Bill Bennett - who himself would die, along with his tandem clinic student, behind a trike three months after Frank - trying to get support for that position and coming back with some irrelevant ambiguous statement.
Bill C. is UNDOUBTEDLY Bill Cummings. He was an early disciple of Donnell's and first appears in the 1983/02 issue of the Skyting newsletter.
The "adverse yaw" comments in Bill's post are pure unadulterated bullshit - I doubt that half a percent of hang glider pilots have a clue what adverse yaw is. The aggravating factors were yaw stability and roll instability.
Adverse yaw is something that we swept wing glider pilots don't hafta worry about. It's over before it starts.
Adverse yaw was something Donnell invented to explain away the fact that gliders using Hewett "center of mass" bridles were locking out and creaming people despite his bogus predictions that the bridle made towing self stabilizing.
And constant transmit - along with tea bag string weak links - was another worse than useless means of rationalizing the use of dangerous tow equipment.
You usually need about three adverse elements (yaw not being one of them) to line up at the same time to get killed or seriously mangled in an aviation incident.
- John's deliberate positioning predisposed him to a lockout.
- There were dust devils floating around.
- And he almost certainly had a line dig.
Throw in late response and a release which required a hand to come off the basetube for good measure.
4. If possible arrange the release so that it doesn't require the pilot's hand to be removed from the control bar. That's a tough one.(Remember with one hand off of the control bar your control authority drops more than 50%. It will be down to maybe 5%.)
It can and does also go to zero and way below - but you'll never get Donnell or a tow park operator to admit that.
Notice all the discussion that was generated by Bill's Issue 4 proposal. Good to see that some things never change - ever after thirty years. (What's that you were saying about a "learning curve", Henry?)
Anyway... So right now I don't have a great example of anyone otherwise doing things right seriously messed up by a truck tow who wouldn't have been seriously messed up if he had had a button in his hand or some kind of actuator between his teeth. But that doesn't mean I think it's OK to go up configured like the HHPA Poster Boy.
(The title of that thread was not mine and at that point of my life I had no idea what a stupid evil scumbag Davis was.)
Skim on through and slow down at Paul Farina's posts. His foot launch AT release would be adaptable to platform towing - but you'd hafta have some junk in the airflow if you couldn't manage to stow it after release.
I think the best way to do this would be a button in your hand, a wire up your sleeve, and solenoids at your hips. If I we're flying platform I'd probably do that for myself but that's something that really needs to come as an option from the harness manufacturers to get it up on any scale.
No one is smart in every way. When it comes to anything mechanical I'm a complete idiot.
If you had a crystal ball and could see yourself in a wheelchair for the rest of your life I'll bet you'd very quickly become a mechanical genius.
Right now you're starting to understand that, when it comes to anything mechanical, the people from whom you've getting your stuff are complete idiots. So what you're saying, to some extent, is that you'd rather fly with stuff supplied by complete idiots that you KNOW WILL FAIL rather than take a chance rolling something yourself because you're afraid that it MIGHT fail.
That's the sort of approach that's totally prevented any significant advancement in towing equipment for decades.
I think you'd have much better odds if their shop was in Florida, however.
I think just the opposite. Nothing good has come out of Florida in twenty years and those guys go out of their way to make sure that nothing good hits the air anywhere else. Only good case I can think of for not being too concerned about global warming.
If I had to be 100% sure about everything before I flew, I would never fly.
We should be able to make a tow launch safer than the drive to the flight park.
I can't even be 100% sure about anything. We take many risks when we fly...we minimize them as much as possible, but they'll always be present to some extent.
We haven't begun to try. Tell me one thing that's improved since the advent of rolling tow launches. We can totally eliminate three of the biggest killers in towing - release malfunctions, inaccessible release actuators, and unnecessary weak link failures. Show me any progress on any significant scale.
Did you yourself not indicate that you foot launch without being 100% sure you're hooked in?
No, I indicated that I'm one hundred percent sure that I'm never gonna launch unhooked 'cause every time I launch I'm always one hundred percent sure I'm NOT hooked in.
I had a lot of confidence in my release until recently.
Too bad. The documentation has been out there for a long time. I know by Groundhog Day of this year you had had access to my letter to the FAA - and that Ralph/Brian stuff is in there.
I don't know why I'm having trouble with it, and this kind of thing is why I'll always have a certain degree of distrust for anything mechanical.
Don't mistrust it cause it's mechanical. Mistrust it 'cause it's a stupidly "engineered" piece of crap.
I used the same core off-the-shelf piece of hardware for years but I rigged it like a sailor or glider designer - not some idiot tow park operator. The gate design was dangerous and I was never happy with it but there was ZERO possibility of it not opening when I hit the lanyard. And since I was using it in conjunction with a bridle there was ZERO possibility of a weak link twisting and locking on the gate - à la Robin Strid.
And, truth be told, I know of no in-flight incident of a weak link on the bridle end failing to come off a spinnaker shackle once the thing is open. The loop has to make a minimum size but just about all the ones I see are stupidly, wastefully, dangerously oversized.
I've never once worried about a block and tackle based VG system failing. I've never heard of one failing. Yeah, I suppose the cord can wear through if you're cleating it at the same marks all the time. But you can easily check its integrity whenever you feel like it. My release system is very analogous to a VG system.
It was my release (Lookout spinnaker type). I wasn't very experienced at the time and only had a few tows with it.
According to the USHGA SOPs covering aerotowing:
A release must be placed at the hang glider end of the tow line within easy reach of the pilot. This release shall be operational with zero tow line force up to twice the rated breaking strength of the weak link.
Even that piece o' shit loop of Greenspot that fell apart when you tried to follow the tug is capable of holding to 140 pounds when you'd really prefer that it didn't. So as an AT rated pilot it was your responsibility to verify that release was operable at 280 pounds. (And a proper 1.4 G weak link for that glider would put 250 pounds on it - before doubling.)
So did you EVER CHECK to see what would happen at 280 pounds? 140 pounds? Or did you just do what everybody does and trust the asshole who sold it to you because you ASSUMED he knew what he was doing and - besides - that's what EVERYBODY is using? (Rhetorical question.)
Some aerotow releases, including a few models from prominent schools, have had problems releasing under high tensions. You must VERIFY through tests that a release will work for the tensions that could possibly be encountered. You better figure at least 300 pounds to be modestly confident.
Maybe 8-10 years ago I got several comments from people saying a popular aerotow release (with a bicycle type brake lever) would fail to release at higher tensions. I called and talked to the producer sharing the people's experiences and concerns. I inquired to what tension their releases were tested but he refused to say, just aggressively stated they never had any problems with their releases, they were fine, goodbye, click. Another person tested one and found it started getting really hard to actuate in the range of only 80-100 pounds as I vaguely recall. I noticed they did modify their design but I don't know if they ever really did any engineering tests on it. You should test the release yourself or have someone you trust do it. There is only one aerotow release manufacturer whose product I'd have reasonable confidence in without verifying it myself, the Wallaby release is not it.
And you don't even have the extra four to one mechanical advantage that stupid brake lever gives you.
And if Bill Bryden had the slightest clue what he was looking at he'd have realized in a nanosecond that the modification absolutely destroyed the spinnaker shackle's ability to operate under load.
OK, it might not be blindingly obvious to a halfway intelligent ten-year-old kid that this unmodified Wallaby Release is gonna fail but it should be blindingly obvious to a halfway intelligent ten-year-old kid that you need to load test ONE of these things ONCE before you flood the skies with twenty thousand copies.
It looked fine to me but I had it inspected afterwards by the shop and they pointed out a manufacturing defect of some kind...a metal cylinder wasn't shaped correctly or something.
This thing ain't all that complicated. The spinnaker shackle itself has three moving parts - the gate, latch, and swivel. They weld the swivel to disable it and amend a cable. And they risk your life 'cause they can't even get that much right? How'd you like to get on a passenger jet that they'd had their grubby little hands on?
OK, I watched your videos and saw enough of your tow setup to identify a minimum of six stupid defects that could kill you. Quiz time... List them - including the ones we've discussed. And try to get this done BEFORE you hook up behind a tug again.
...the rest of my flights were foot launched...
And what were you doing to reduce the probability of becoming the third gliderless body in need of recovery from the slope below that launch?
Single. I looked at it to investigate the feasibility of me recreating it. I didn't bother with the two-point because I've seen enough of it to know it's beyond my capability.
Tad Eareckson wrote:'Cause you think there's some possibility you could do worse than the crap you're using now?
YES. If you don't put things together right they could fall apart at an inopportune time. At least I know the stuff I'm using has a good enough track record that virtually no one sees the need to improve it (although I can't really say that since Lookout replaced their spinnaker releases).
Tad Eareckson wrote:If your upper anchor point is a bit fore of the hang point - which, for the Sport 2, Wills Wing recommends it to be - using a secondary as a backup can put you in instant Len Smith mode, i.e. with your life dependent upon a clean parachute deployment.
This is another thing you've made me aware of and I can't believe it isn't taught.
Tad Eareckson wrote:
Zack C wrote:Usually it activates on the second pull...
And that wasn't scaring the crap out of you?
To be more precise, it always activated by the second pull, and since the first time I had to pull it twice, it still activated on the first pull most of the time. Anyway, the only reason this didn't freak me out more is that the release always released - I just had to pull harder than I was accustomed. In an emergency I expect I'd yank the mofo pretty hard. But that said, I did place an order for one of Lookout's new releases when I was there, and that was before my tow flight there. I haven't used the release since that flight and I don't plan to use it again unless I can discover and fix whatever's causing the resistance.
Tad Eareckson wrote:I can set you up with barrel releases.
I appreciate that...let's discuss this off-line. I especially don't want to continue using the Bailey release if I'm going to be using a stronger weak link.
About John Woiwode, I read his account just yesterday when going through accident reports in your FAA document. My reaction was, 'nah, surely he doesn't mean he was aligning with the road in a crosswind...'
Tad Eareckson wrote:Adverse yaw is something that we swept wing glider pilots don't hafta worry about. It's over before it starts.
We're getting off topic, but I don't agree that it's over before it starts...I find it quite noticeable with quick bank changes. I created this video to illustrate it for someone who kept confusing sideslip with adverse yaw (password = 'red'):
But it's not something we can do anything about. Pagen says it delays roll response (more so on gliders with less sweep), but I don't think that's true. Delay the turn, perhaps.
Tad Eareckson wrote:If you had a crystal ball and could see yourself in a wheelchair for the rest of your life I'll bet you'd very quickly become a mechanical genius.
I don't think you can become a genius (at least not with current technology...).
Tad Eareckson wrote:So what you're saying, to some extent, is that you'd rather fly with stuff supplied by complete idiots that you KNOW WILL FAIL rather than take a chance rolling something yourself because you're afraid that it MIGHT fail.
They're far less idiots than I and their work is a lot better than what I'd have come up with on my own. And I don't know that it WILL fail. I know it MIGHT fail. I think there's less of a chance of that happening with the stuff I bought (well, not counting my spinnaker release in its current state) than anything I'd make.
Tad Eareckson wrote:That's the sort of approach that's totally prevented any significant advancement in towing equipment for decades.
And do you think if I built my own release anything would change? You built your releases and have been a lot more vocal about the issue than I'll ever be...what's changed as a result?
Tad Eareckson wrote:
Zack C wrote:We take many risks when we fly...we minimize them as much as possible, but they'll always be present to some extent.
We haven't begun to try.
I missed the irony in that statement when I wrote it. By 'we' I meant individuals. As pilots we minimize our risks as much as we can with what we have to work with (including our equipment and our knowledge). But the sport has a lot of room for improvement (including equipment and training).
Tad Eareckson wrote:No, I indicated that I'm one hundred percent sure that I'm never gonna launch unhooked 'cause every time I launch I'm always one hundred percent sure I'm NOT hooked in.
C'mon, 100%? Charles gave an account of lift-and-tug failing him. If the technique's not completely trustworthy, there's always a chance you could launch unhooked.
Tad Eareckson wrote:I know by Groundhog Day of this year you had had access to my letter to the FAA - and that Ralph/Brian stuff is in there.
That document is huge. I hadn't read much of it until recently. I had confidence in my release because it never failed me in all the years I used it and I hadn't heard of it failing for anyone else.
I had a very different mindset too back then and trusted the people that made my equipment. Since then I've realized (largely due to this discussion) that while I can certainly consider the advice of others, I can't trust anyone in this sport but myself (and maybe the people at Wills Wing).
Tad Eareckson wrote:OK, I watched your videos and saw enough of your tow setup to identify a minimum of six stupid defects that could kill you. Quiz time... List them - including the ones we've discussed.
All I've got is a primary release that sucks, a secondary release that sucks, and an understrength weak link. Unless you want to get particular about why the releases suck (primary requires excessive force to activate and can snag or degrade weak links; secondary requires removing a hand from the bar and can fail or be difficult to activate under high tension). Other than that, I dunno...maybe shoulder bridle is too long? Seems like it would interfere with my helmet if it was shorter.
Tad Eareckson wrote:And what were you doing to reduce the probability of becoming the third gliderless body in need of recovery from the slope below that launch?
Nothing...my wire crew had me covered. Kidding. I followed the standard Lookout procedure of doing a hang check immediately prior to getting on the ramp and launched within 30 seconds. But what was different about this trip is that on both launches I stood at the edge of the ramp wondering if I was hooked in, which I never used to do. I knew I was because I remembered checking 30 seconds ago...I know, not good enough. I haven't revised my procedure yet because I haven't had time to mess with my harness. But my mindset is changing at least.
I didn't bother with the two-point because I've seen enough of it to know it's beyond my capability.
The bungee stuff in the basetube is nice but it's fairly negligible with respect to safety. If I were gonna do your glider for myself I probably wouldn't bother with it. Minus that system the job gets real easy.
If you don't put things together right they could fall apart at an inopportune time.
Your Sport 2 is a sophisticated and complex piece of hardware but it's virtually impossible to set it up wrongly or incompletely and still be able to pick it up and carry it to launch. Without using tools it would be virtually impossible to sabotage it such that you could get somebody to launch and kill himself (assuming he's hooked to it).
Some stuff is either together or it's not.
At least I know the stuff I'm using has a good enough track record that no one sees the need to improve it...
In REAL aviation you don't go up with stuff because it "has a good enough track record". You don't even let it start establishing a track record until it's been demonstrated to meet a set of engineering standards.
The unbelievably stupid Bailey Release has an EXCELLENT track record for a variety of reasons.
All deaths associated with people not being able to get to or pull it in an emergency are thrown out of the data pool and attributed to "pilot error".
- Shouldn't have launched in strong thermal conditions.
- Should've had more ribbons along the runway.
- Should've set the cart another notch nose down.
- Shouldn't have been towing one point.
- Didn't grip the barrel properly.
- Didn't have enough airtime to be flying that bladewing.
- Hadn't stayed current.
- Should've released at the first sign of trouble. (Or - at Quest - before.)
- Made no effort to release.
- Just froze.
It's almost never flown as a primary or solo secondary with a weak link strong enough to survive mild turbulence.
It's never flown as a tandem primary - when it's subjected to a 200 pound weak link.
It virtually never sees action as a tandem secondary 'cause the secondary weak link always blows in the event of a primary bridle wrap.
Lockouts within striking range of the surface are extremely rare because virtually all aerotowed gliders are launched on wheels and the pilot starts and stays prone with both hands on the basetube and gets into the air with a lot of speed.
There's a tug driver with an eye on the mirror and a finger on the trigger.
Contrary to popular belief, dangerous situations very rarely involve much in the way of tension.
Dude! Sport aviation in dangerous. Shit happens!!! If you can't deal with it then I suggest you sell your equipment and take up a safe activity like checkers.
When Jim got me locked out to the right, I couldn't keep the pitch of the glider with one hand for more than a second (the pressure was a zillion pounds, more or less), but the F'ing release slid around when I tried to hit it. The barrel release wouldn't work because we had too much pressure on it.
Anyhow, the tandem can indeed perform big wingovers, as I demonstrated when I finally got separated from the tug.
But the track records of these things are good enough that no one sees the need to improve them.
The only way this shit is ever gonna get grounded is if it leaps off of the glider at the staging area and disembowels Justin Bieber in front of his mother - live on a special holiday edition of the Today show.
...(although I can't really say that since Lookout replaced their spinnaker releases).
Yeah? Did they ever test the new mechanism to see if it was up to the job before they put it in the air? In the previous twenty years did anyone ever test the spinnaker shackle to see if it was up to the job it was being asked to do? Did they have any idea if the new mechanism represented an improvement before they went into mass production?
This is another thing you've made me aware of and I can't believe it isn't taught.
Not only is it not taught...
I've stood next to the Target trainer at Ridgely listening to Sunny tell a student that the Quest release doesn't work so just use the backup - with blood oozing out of the tip of my tongue.
Anyway, the only reason this didn't freak me out more is that the release always released - I just had to pull harder than I was accustomed.
And for nearly 22 years nobody was worried much about a little damage to the heat shielding from stray bits of foam insulation. What was the term John used? Normalization of deviance?
In an emergency I expect I'd yank the mofo pretty hard.
In an emergency is there a possibility that your hand would be locked on the mofoing basetube pretty hard?
I haven't used the release since that flight and I don't plan to use it again unless I can discover and fix whatever's causing the resistance.
The resistance happening between the mechanism and your hand is gonna be exactly the same for both assemblies.
I especially don't want to continue using the Bailey release if I'm going to be using a stronger weak link.
Glad I didn't hafta point that out to you. See! You're not a total idiot on mechanics after all. Keep working with that.
My reaction was, 'nah, surely he doesn't mean he was aligning with the road in a crosswind...'
Yeah. My reaction was that it was such an aberration that it didn't even register.
We're getting off topic, but I don't agree that it's over before it starts...I find it quite noticeable with quick bank changes. I created this video to illustrate it for someone who kept confusing sideslip with adverse yaw...
I may be treading on thin ice here but anyway...
- You're riding your bike - to make it consistent with the video - in England (on the wrong side of the road).
- You're riding straight, on the absolute edge of the pavement, and there's an abrupt drop-off of a couple of inches to the gravel.
- It's almost impossible to get yourself back on the road enough for a little breathing room.
- 'Cause you turn a bike by moving your high mass body to the side to which you wanna turn and Newton says that the instant you do that your low mass bicycle is gonna go the other way.
- And lotsa times you end up being mildly screwed. (I know you've had this experience.)
That's what that video reminds me of. So are we seeing adverse yaw or similar action/reaction stuff?
You move to the inside, the bike or glider moves to the outside, then everybody's centered, leaning into the turn, pulling Gs, and making it happen.
I'm having as hard a time visualizing the glider NOT doing that as I would the bicycle.
The sweep is constantly resisting yaw. If we're looking at an effect of adverse yaw, is the swept wing surprised by it and in need of a couple of seconds to get its shit together and react?
Pagen says it delays roll response (more so on gliders with less sweep)...
Gliders with less sweep also tend to be tighter and wider. Neither of those qualities does a whole lot for roll response either.
But yes, whether or not we're seeing it, for any given glider there's nothing we can do about adverse yaw anyway 'cept use speed and muscle to try to make the thing do what we want it to. And I just have a real short fuse when I hear people talking about it in reference to towing and lockouts.
They're far less idiots than I...
No.
...and their work is a lot better than what I'd have come up with on my own.
You think you're an idiot. That's the absolute one best thing one can have going for him in aviation. The people who don't launch unhooked are the ones who know they're idiots. The more confidence one has in himself the more likely he is to find himself dangling from the basetube.
I think if you were forced to design your own release you'd be so scared of fucking up that you'd research everything you could get your hands on to avoid repeating mistakes and reinventing wheels and bench test the crap out of anything you intended to put in the air. None of these other assholes - except, to some extent, Peter Birren - has done that.
And do you think if I built my own release anything would change? You built your releases and have been a lot more vocal about the issue than I'll ever be...what's changed as a result?
John Glime - 2009/04/13 18:09:32 UTC
Salt Lake City
Not being constructive? There is one person who has put more thought and time into releases than anyone. That person is Tad. He explains the pros and cons to every release out there. I gave you the link to more release information than the average person could ever digest, and I didn't get a thank you. Just you bitching that we aren't being constructive. What more could you want? He has created something that is a solution, but no one is using it... apparently you aren't interested either. So what gives??? What do you want us to tell you? Your concerns echo Tad's concerns, so why not use his system? Every other system out there has known flaws.
A few people are trying to do things right.
Joe Street - 2009/04/02 20:01:16 UTC
Hi Tad;
I've been trying to find straight pins to make a release like you recommend. No luck with google. Can you give me the source? Do you have instructions on how to make the barrel/pin type release? I would like to standardize on that with our new club now that we have a few members and I just know that I'll get less resistance if I have some pre-made releases to hand out rather than telling folks to go read your stuff and make their own. I'm also going to start beating it into them about thinking in terms of G load for the weak link instead of the ubiquitous single loop of Greenspot. Old habits die soooo hard.
The more decent people we have innovating, implementing, and writing the more we advance against the dregs running the shows.
By the way...
Chapters and its officers are required to be goodwill ambassadors for USHPA and are expected to work within the USHPA committee system to support USHPA's image and support USHPA programs. Chapters cannot on one hand participate in USHPA subsidized programs and on the other take actions which are detrimental to the USHPA and the sport. Examples of actions which may be detrimental are:
1. Any correspondence in any public media which is critical of USHPA's programs and policies.
2. Any correspondence in any public media which is critical of other Chapters.
3. Any Club policy which is detrimental or causes harm to any USHPA program.
Sound familiar?
It's never gonna be established organizations and flight parks that are gonna make positive changes. They're gonna do everything they can to prevent them.
As pilots we minimize our risks as much as we can with what we have to work with (including our equipment and our knowledge). But the sport has a lot of room for improvement (including equipment and training).
Some risks we have to settle for minimizing many others we can TOTALLY ELIMINATE. We can minimize the risk of breaking an arm at a half decent field by rolling in the landing. We can totally eliminate the risk of a release failure.
Virtually all of the knowledge that's necessary to do things right and which should be universally understood and implemented has been available in the literature for at least a quarter century - a lot of it was put to rest by Wilbur and Orville near the beginning of the last century. But we go nowhere.
C'mon, 100%? Charles gave an account of lift-and-tug failing him. If the technique's not completely trustworthy, there's always a chance you could launch unhooked.
Personal experience: Many moons ago, I read a post in the HG magazine that suggested lifting your harness to see if your legs are properly through the leg loops of your harness. Sounded good to me, so I adopted the method. One day at Pack, I was distracted by a bunch of wuffos and failed to put my legs through the leg loops. (I believe there is another lesson here). As part of my pre-launch routine, I lifted the glider and felt what I thought were my leg loops tugging at my crotch. What I was actually feeling was my shorts being tugged by my custom fitting harness. So off I went...
I would implore all HG pilots who currently use the technique to abandon it, and discourage anyone thinking about adopting the technique to not do so. Reach down and positively feel those leg loops around your legs!
Corollary axiom: Because I have had to launch last so often with no assistance, and because launching without being hooked in sucks, when foot launching, I always attach my harness to my HG as the last step in putting together my HG. This assures I do not launch unhooked. Also, it makes getting into my harness much easier.
He missed the leg loops - which was a failure in setup procedure.;
He used a hook-in check - which is supposed to be used as the commencement of his launch sequence - in place of his preflight procedure and got a false positive on half of what it's supposed to catch.
So off he went... completely ignoring - as always - the SOPs which require the pilot to verify his connection JUST PRIOR TO LAUNCH.
So because he screwed the setup procedure pooch, essentially skipped the relevant preflight inspection, and totally skipped the first and most critical element of his launch sequence he left the ramp without his leg loops.
Note that HE DID NOT LAUNCH UNHOOKED.
Also note that he didn't suffer so much as a scratch - despite the triple alignment.
I have very little doubt that if we swapped bodies and locations for an hour I could figure out how to eliminate the false positive issue from the lift and tug check.
He joined a religious cult which mandates that its zombies:
- adhere to a sacred ritual in the setup area - regardless of any issues of practicality and safety;
- forever renounce and denounce the USHGA SOP which best addresses failure to hook in; and
- always run off the cliff with total faith in the validity of the religious tenet.
THOU SHALT HAVE NO OTHER GOD BEFORE ME! Or alongside, after, or on the same continent. OK, who's up for some Kool-Aid?
Ain't none of this gonna happen to me.
That document is huge. I hadn't read much of it until recently.
That's OK. 99 percent of the people who attacked it and me with all the viciousness they could muster hadn't read ANY of it. And I don't think it got so much as a glance by anyone at the FAA. (And I don't think anybody at USHGA can read.)
I would agree that our safety record is much better than he makes it out to be. But there's still room for improvement.
I wasn't making anything out to be anything. I was presenting evidence - none of which has ever been called into question by anyone. It was just so much easier to ignore - just like the incidents were at the time.
I had a very different mindset too back then and trusted the people that made my equipment.
Yeah, tell me about it. Although I didn't know it at the time - 1984/05/12 - a Hewett bridle put me in just about the most insanely dangerous situation I'd ever been in on a hang glider.
Since then I've realized (largely due to this discussion) that while I can certainly consider the advice of others, I can't trust anyone in this sport but myself...
Too bad, isn't it? That's how come last summer I had to tell my nephew no freakin' way. So many total assholes, a few good people with some or most of it together, but nobody I know who has the whole picture together.
Just in your little neck of the woods in the past year... Two hook-in failures - one with serious consequences, two students of certified instructors dead, and virtually nothing in the way of overhauling the system.
If I sent him into General Aviation I wouldn't hafta worry too much about everyone being on the same page and he could find the textbooks in the nonfiction section of the library.
And hopefully this discussion will evolve into a resource worthwhile hang glider pilots can use as a life raft.
...(and maybe the people at Wills Wing).
That platform launch / nosewires hardware issue was REAL disappointing.
But otherwise, they're pretty good - although I can catch them on a few things.
The gliders we can trust pretty much. If my nephew went up the glider itself wouldn't be anything I'd worry about. And that's because they're all certified to internationally recognized standards and physics is calling the shots - not some brain damaged tug jockey.
And if we can get them to build the releases in and make some more tow equipment available...
All I've got is a primary release that sucks, a secondary release that sucks...
More specifically, primary and secondary releases which fail to comply with any reasonable interpretation of the USHGA SOPs.
...and an understrength weak link.
And...
USHGA
A weak link must be placed at both ends of the tow line.
Is there a weak link on your end of the towline?
Ugly lockout, 500 feet.
You release or your primary weak link blows. But because of the speed at which the planes are heading off in different directions...
Oh it happens.
I have, all the guys I work with have.
(Our average is 1 in 1,000 tows)
Oh yeah... an other fun fact for ya... ya know when it's far more likely to happen? During a lockout. When we're doing lockout training, the odds go from 1 in 1,000 to over 50/50.
So in a critical situation there's more than a five hundred fold increase in the failure rate of Highland Aerosports Shit.
And he's just talking about the short secondary bridle.
So now your primary bridle is welded to the tow ring.
Don't bother even thinking about going for the Bailey on your left shoulder 'cause the secondary weak link on your right shoulder blew the nanosecond the primary bridle wrapped.
You have a secondary long enough to equip a team to summit K2 and half of that has to feed out at 200 mph through the unprotected eye at the bottom end of the primary bridle which - remember? - just locked onto the tow ring. And Highland Jim has just told you that the odds of that happening are worse than three-bullet Russian roulette.
So now you're still locked out on tow and out of weak links on your end.
How 'bout one on the other end of the towline?
USHGA
A weak link must be placed at both ends of the tow line.
Yeah, right.
From Page 349 of Dennis's and Bill's idiot book...
I witnessed a tug pilot descend low over trees. His towline hit the trees and caught. His weak link broke but the bridle whipped around the towline and held it fast. The pilot was saved by the fact that the towline broke!
So now you have no weak link protection for your glider or release. And your release has to be the stupidest "design" ever to come out of the workshop of a tool using mammal - EVER.
Ever try to blow a Bailey at two hundred pounds? Four? Six? Lauren couldn't budge it at one.
Other than that, I dunno...maybe shoulder bridle is too long?
Do ya think?
Seems like it would interfere with my helmet if it was shorter.
Worried about your helmet getting interfered with?
As Ralph mentioned, I didn't see Holly's accident, but Steve Wendt (Blue Sky Hang Gliding - Manquin, Virginia) saw it all (as did several others). For now, all I'm comfortable saying is that Holly opted to aerotow on her Moyes Litesport (one point - Bailey). From what Steve told me, she experienced oscillations shortly after takeoff which quickly became severe. At an altitude somewhere between 50 and 100 feet (we don't know for sure) there was a lockout situation with the glider at a near 90-degree angle. When a line broke (I don't know which one), Holly's glider recoiled backwards, almost fully inverted, then partially recovered in a dive toward the ground.
Steve saw Holly pulling in for speed. He speculated had she been ten to twenty feet higher, she might have made it... and ten to twenty feet lower, she could have died. Whatever the case, she hit the ground hard at something less than a vertical angle. Her Charly Insider full-face helmet was broken through in two places (the chin and next to her eye), and Steve believes the breaks absorbed some of the impact and probably saved her life.
Winter boredom and the Oz Report (Robin Strid - 2005/01/09) resulted in my invention of "the squid" AT shoulder release. This is a two ring (or three - haven't decided which is better) where the final loop runs through a grommet and you hold it in your teeth. Want off? Open your mouth. When you are a hundred feet up and presumably out of danger you slide a barrel (the body of the squid) over the loop which crimps it at the grommet and you have a standard barrel release. I can hold on with my teeth all the way and not use the slider/keeper but gotta be sure I have fresh polident.
Tried it at Manquin and down in Florida. Seems to work fine. (Flew with a standard barrel on the other side just in case.) Also gets a lot of laughs. Show it to you.
NOTE THE DATES on those two posts.
That CRASH (notice I'm not saying "accident") WOULD NOT HAVE HAPPENED if Steve Wendt hadn't been too busy laughing to notice that someone had shown up with something that would make his training and tow operation less of a death trap.
On 2004/09/20 I had made a special trip to Manquin to show Steve my two point AT release system. Got a similar reception and degree of interest.
Also met one of Steve's student's - Bill Priday - whose gliderless body would be recovered from below the Whitwell launch escarpment a year and eleven days later. Steve's a diehard hang check man - doesn't believe in hook-in checks.
The first report to the DC area was relayed from Scott, who was at launch, to Holly. And Linda Baskerville - a witness to the Holly fiasco - was also present for the Sequatchie plummet. Small world.
But I digress...
Steve Goldman - 1982/12
Dear Donnell,
The release mechanism is dangerous, again this may be because of old habits since virtually all of the pilots I observed were experienced tow pilots.
In a desperate situation it can be difficult to release, which happened to me twice. In the first incident, as I said earlier, I got into violent yaw oscillations. There was no way that I could let go of the control bar and pull the release. In the second case, due to winch operator error, I was "launched" on the "cut" signal, I was not even holding the glider, and when the winch started I stumbled and was dragged. Once this happens you can't get to the release and you have to depend on someone cutting the power.
All of my releases will handle 750 pounds of towline tension with light actuation forces. The system oozes mechanical advantage. Hands stay in place at all times except for non emergency use of the barrel release. No matter what happens all releases are weak link protected at all times. There's very little chance of a primary bridle wrap and virtually no possibility that I'll hafta use a secondary. There is ZERO possibility of a secondary bridle wrap because it's so short and thick that it can't form a knot. It's bulletproof.
The crap you're using looks like it was designed by some psychopath to kill you in as many different ways as possible and still make it look like an accident.
Nothing...my wire crew had me covered. Kidding. I followed the standard Lookout procedure of doing a hang check immediately prior to getting on the ramp and launched within 30 seconds.
The hang check just off the back of the ramp was the last step of your PREFLIGHT PROCEDURE.
The hook-in check - whatever you can manage or come up with - is the first step of your LAUNCH SEQUENCE.
You didn't do a hook-in check. The standard Lookout procedure kills people.
Getting verification from your wire crew JUST PRIOR TO LAUNCH would've been better than NOTHING. I would consider that a not horrible excuse for satisfying the requirement.
Forget lift and tug for the moment. If everybody made it a personal rule to get verification from SOMEBODY standing nearby JUST PRIOR TO LAUNCH every time failure to hook in rates would plummet.
If B Asher had said to you "Unhooked." it wouldn't have mattered that you were looking through a camera and focusing on keeping it steady. He would NOT have launched unhooked.
Brief your crew as your getting on the ramp.
"When I'm ready to launch I'm gonna say 'UNHOOKED.' I want anyone and everyone who's in a position to see to contradict me if I'm wrong by saying 'HOOKED!' Then I'm gonna say 'Clear.'"
That briefing and sequence would ELECTRIFY a pilot launch crew. Light bulbs would start coming on. "Whoa! I'm gonna start using that!" The idea would spread.
But what was different about this trip is that on both launches I stood at the edge of the ramp wondering if I was hooked in, which I never used to do.
That too is better than nothing and will go a long way to keeping YOU safe - but will have absolutely no effect on anybody else.
As with many changes in avaition, change is approached with a bit of skepticism. Rightfully so. There's something to be said for "tried and true" methods... by strapping on somehting new, you become a test pilot. The unknown and unforseen become your greatest risk factors. It's up to each of us to individually asses the risks/rewards for ourselves.
Yeah Jim, and as with spelling in avaition, spelling is approached with skepticism - because it's totally beyond the grasp of the vast majority of pilots.
Change is not within the purview of pilots. There are way too many individual asses in the population for change to even happen - let alone move in a positive direction. In REAL aviation individual asses aren't allowed to strap on anything new and become TEST PILOTS. It gets tested on the ground so there are no surprises in the air.
Pilots are there to stick to the rules handed to them by people who understand physics and fly stuff designed and certified by people with brains and competence. When you let pilots "DESIGN" stuff, put it in the air without meeting any standards of engineering or sanity, and simply DECLARE it to be "tried and true" regardless of its performance and record you get a lot of people needlessly killed.
Tommy Thompson - 2010/12/15 11:13:16 UTC
Whitewater
there has been times while on tow when I have felt handicapped(hands suck to the base or down tubes when things get real interesting)
Seems the blow tube has been used for many years to help over come real physical limitations, why can't that also be used on a HGing release?
Tommy, I appreciate your motivation - but your spelling stucks too.
Jim Rooney - 2010/12/15 23:30:11 UTC
There does tend to be a lot of "Reinventing The Wheel" that goes on when people try to "Build a Better Mousetrap".
This is fine and dandy if you realize and accept that you are quite literally experimenting with your life.
As over the top as that sounds, it's pretty damn accurate.
I get called a wet blanket a lot, and that's ok. But I've seen a lot of my friends try to put themselves in the hospital "experimenting" with this stuff.
I also heard you get referred to as "Mister-Know-It-All" at dinner one night in Ridgely. And it wasn't 'cause that individual thought you knew it all.
You have FRIENDS? I guess so. Standards in hang gliding have always sucked.
So how did these alleged friends TRY to put themselves in the hospital? Apparently none of them succeeded anywhere near as well as many of our "tried and true" equipment users have.
Please realize that there are hidden issues with all this stuff.
It is by no means as straight forward as it looks.
Yes. This business of getting a mechanism to let go of one end of a string is fraught with unfathomable mysteries. The sailplane people seem to have gotten it down pretty good - but they violate hang gliding's sacred code of using no more than two moving parts and keeping the cost of construction down to twenty bucks.
Ok... preachy time over...
Isn't this the issue that the "Lookout" style of release addresses?
(loop through the hand/pinky on the base tube)
Ralph Sickinger - 2000/08/26 22:18:20 UTC
Under sled conditions, I decided to borrow Brian Vant-Hull's glider instead of setting up my own, since we both fly the same type of glider. Brian's release is a different style, but I tested it twice during preflight to make sure I was familiar with it. After towing to altitude, Sunny waved me off; I pulled on the release (hard), but nothing happened! After the second failed attempt to release, I thought about releasing from the secondary, but before I could move my hand the tug stalled and started to fall; Sunny had no choice but to gun the engine in attempt to regain flying speed, but this resulted in a sudden and severe pull on the harness and glider; I was only able to pull on the release again, while simultaneously praying for the weak link to break. The release finally opened, and I was free of the tug.
Brian Vant-Hull - 2000/08/28 22:49:13 UTC
I purchased my release (the one Ralph used) at Lookout Mountain over a year ago, but never had any problems until the Ridgely Fly-In, where the same thing happened. I pulled three or four times on the release, then finally went to the secondary, by which time I was high above the tug and Sunny (is there a connection here?) was frantically waving me off.
Yeah Jim, it addresses the issue just fine. It addresses the issue so well that even Highland Aerosports wouldn't offer it along with all the other dangerous junk they sell and put on their trainers.
Tommy Thompson - 2010/12/16 11:36:24 UTC
I'v always thought the less moving parts, the better.
So how come the VG system on a U2 works just fine but the Lockout release velcroed onto it doesn't? How come when you get on a DC-10 you have an infinitely lower probability of ANY of its ten zillion parts failing than you do of a Lockout release? Maybe you should start thinking about ADDING enough parts to do the job right.
Jim Rooney - 2010/12/16 18:47:05 UTC
Oh, I've heard the "everything we do is an experiment" line before.
The trouble is, it's not.
Yeah. We already knew why Wallaby, Quest, Lockout, and Bailey releases would malfunction and kill people before they started going up. There was absolutely no need to experiment.
I've seen experimentation with towing gear more than anything else in HG.
Why do you think that is? Possibly 'cause everybody and his dog knows that ALL of the commercially available stuff totally sucks?
I've not seen many go out and try to build their own sails for example. But for some reason, towing gear is exempt from this.
That's 'cause, whereas the sails are designed by smart engineers who have kept refining ideas for decades, test and certify them, and end up within a hundredth of glide point of the competition, the releases are slapped together by idiots at flight parks who answer to no one, flood the market with crap, and do their damnedest to make sure that nothing better ever sees the light of day.
The difference is what we do has been done by thousands of people already.
And survived by hundreds.
It's been tested... a lot.
And FAILS... a lot. And kills people... a lot. But the important thing is that it's been TESTED - in the air.
What we do is free of the experimentation part.
Right. You just never gave a rat's ass about the results.
It's still dangerous, but not at the level of building new gear is. Not even close.
You have a scrap of data to support that statement? Or are you just pulling whatever you feel like out of your ass - as usual?
That's what people fail to realize.
It's no small difference. It's a huge chasm.
Yeah, right.
Notice how I'm not saying to not do it.
Go forth and experiment. That's great... that's how we improve things.
I'm just warning you of that chasm.
A few years ago, I started refusing to tow people with home made gear.
So, while you're not saying to not do it, you ARE saying that if you DO do it you'll make sure it never gets into the air as long as your knuckle dragging cult of tug jockeys has any say in the matter.
I've personally refused to tow a flight park owner over this very issue. I didn't want to clash, but I wasn't towing him. Yup, he wanted to tow with a doubled up weaklink. He eventually towed (behind me) with a single and sorry to disappoint any drama mongers, we're still friends. And lone gun crazy Rooney? Ten other tow pilots turned him down that day for the same reason.
Same way you assholes make sure nobody gets into the air with anything over a loop of 130 pound Greenspot as a weak link.
I like the idea of improving gear, but the lack of appreciation for the world they were stepping into didn't sit with me.
And who the fuck are you? You ever contributed a goddam thing towards the advancement of hang gliding technology or safety?
The Press - 2006/03/15
The Civil Aviation Authority (CAA) is urgently pushing for new hang-gliding industry standards after learning a hang-gliding pilot who suffered serious injuries in a crash three weeks ago had not clipped himself on to the glider.
Extreme Air tandem gliding pilot James (Jim) Rooney safely clipped his passenger into the glider before departing from the Coronet Peak launch site, near Queenstown, CAA sports and recreation manager Rex Kenny said yesterday.
However, he took off without attaching himself.
In a video, he was seen to hold on to the glider for about fifty meters before hitting power lines.
Rooney and the passenger fell about fifteen meters to the ground.
For example... flying with the new gear in mid day conditions?
Are you kidding me????
When Jim got me locked out to the right, I couldn't keep the pitch of the glider with one hand for more than a second (the pressure was a zillion pounds, more or less), but the F'ing release slid around when I tried to hit it. The barrel release wouldn't work because we had too much pressure on it.
Anyhow, the tandem can indeed perform big wingovers, as I demonstrated when I finally got separated from the tug.
Yeah, fer sure, stay with the "tried and true" stuff.
Approach it for what it is... completely untested and very experimental gear which will likely fail in new and unforseen ways as it tries it's damndest to kill you... and then we can talk.
And, of course, by TESTING you mean only throwing it up in the air and seeing if anybody dies. Whether or not it meets the specs defined in the USHGA SOPs.
Tommy Thompson - 2010/12/16 19:36:43 UTC
...the current technology in towing releases leaves lots of room for improvements.
And very little room for getting worse.
Jim Rooney - 2010/12/16 20:01:12 UTC
However, none of that changes the fact that there is a drastic difference between flying with production gear, as imperfect as it may be, and flying with completely untested gear.
Chris Bulger, Rob Richardson, Mike Haas, Davis Straub, Robin Strid, Holly Korzilius, James Simpson, Stephen Elliot... All injured or killed on and because of production gear. But it's OK 'cause it's production gear.
Dawson - 2010/12/16 23:11:13 UTC
Tommy, it seems to me that a tow release needs to be as infallible as possible in two particular areas.
1) Must release when the pilot wishes to release.
2) Must ONLY release when the pilot wishes to release.
But it's OK to tow with a weak link that blows at random.
Jim Rooney - 2010/12/18 20:12:54 UTC
I love innovation.
For precisely the same reason an ivory trafficker with an AK-47 loves elephants - they're so freakin' easy to kill and carve up.
But why bother with improving releases if you can just push out to blow the weak link when you're locked out with both hands busy? End of problem, right?
However, this isn't the type of thing that's "puzzled out" on the internet. AKA, you're not going to figure it out here. This is real world engineering stuff. Five minutes with Bobby Bailey is worth more than anything you're going to achieve here. Pick your engineer of choice, Bobby's just a very good example.
When Jim got me locked out to the right, I couldn't keep the pitch of the glider with one hand for more than a second (the pressure was a zillion pounds, more or less), but the F'ing release slid around when I tried to hit it. The barrel release wouldn't work because we had too much pressure on it.
Anyhow, the tandem can indeed perform big wingovers, as I demonstrated when I finally got separated from the tug.
I, Brian Vant-Hull (hereafter referred to variously as "I" or "me") in the company of James Rooney (hereafter variously referred to as "Jim" or "Rooney" (collectively referred to as "we")) do attest that on Saturday, June 28, I have laid hands upon and inspected, under controlled and numerically repeatable conditions, the barrel release (hereafter referred to as "Tad's Release") constructed by Thaddeus Eareckson (hereafter referred to as "Tad") and have compared it under identical conditions to the 'Bailey' barrel release.
We found that under a load of 194 pounds the Bailey release required a very strong tug (I couldn't do it at first) while Tad's release could be actuated with the friction of two fingers at twice that load. Rooney could actuate the Bailey release immediately, but admitted they practiced this during tandem training, so he knew to wrap his fingers over the top and pull vigorously. I do not believe that if the forces became this strong I could operate the Bailey release with the alacrity required under lockout conditions, but could actuate the Tad release. I won't speak for Jim, but
Under weight of these observations, I do attest that TAD's RELEASE is SUPERIOR to the BAILEY RELEASE and that the BAILEY RELEASE is SERIOUSLY FLAWED UNDER HIGH LOADS.
In witness thereof, I attach my signature and moreover have purchased Tad's release.
Yeah, good ol' Bobby. He da MAN! Too bad he's totally clueless with respect weak links and the principle of the second class lever.
About John Woiwode, I read his account just yesterday when going through accident reports in your FAA document. My reaction was, 'nah, surely he doesn't mean he was aligning with the road in a crosswind...'
Apparently he DOES. (And don't call me Surely.)
Donnell Hewett - 1982/11
Some of you have wondered why I have not bought a more modern glider than the old standard Rogallo which was used to develop the skyting system. Well, I just did. I bought a brand spanking new UP Gemini 164.
My glider arrived at the dealer's shop approximately one month after I ordered it. And on Saturday, October 16, 1982, my family and I drove to Austin to pick it up. I received some instructions on its use and drove back to Kingsville on the same day.
It was the next Tuesday before I actually flew the glider. After work and before sundown, my crew and I drove out to the County Airport where we normally fly and set up the glider and the towing equipment.
The winds at our flying site were quite typical: strong, crossways, and gusty. Actually, they were not all that bad on this particular day. They were about 60 degrees crossways to the runway and blowing at 10 to 15 mph. The turbulence was milder than usual.
I began testing the glider's handling characteristics in the wind without being hooked in; then I did some testing while being hooked in; and finally I attached the glider and myself to the bridle of the towing system. During these experiments we were using only 100 ft of towline and, therefore, were able to align the whole system directly with the wind. (We would worry about the crosswind problem later on - if and when we decided to use the longer towline to tow the glider.)
FIRST FLIGHT
Under normal circumstances a crosswind takeoff of 45 degrees to 60 degrees would be no problem, but this situation was not exactly "normal". In fact, with this new glider, both the takeoff and the landing could prove to be a problem.
I decided to take off and then climb slowly as long as everything was under control. If anything went wrong, I would release and land the glider into the wind and on the runway - if possible. Everything was ready and I was in position to go. From my point of view the flight went something like this:
All right, Donnell, make your final check to see that everything is correct. The vehicle is ready (having already given its signal). The bridle line is untangled. You're hooked in. The glider's nose is into the wind. The towline is tight. The right wing (the one facing the tow vehicle) is high as it should be for crosswind takeoffs. Are you mentally and emotionally ready? Yes! Then give the GO signal.
You're committed now, so you better keep the glider positioned properly while the vehicle gains speed. The towline's getting tighter. Now take a few slow steps, holding back on the towline while the rope stretches. The glider's flying. Faster now, and we're airborne!
Good takeoff. Everything's under control. We're climbing gradually at about the planned rate. The glider is crabbing sideways over the runway as it should in the crosswind situation.
WHAT'S THE MATTER? The glider wants to turn left! You better shift your weight to the right. Hey, it's still turning left! Shift your weight some more! Watch out, the keel line is touching the right flying wire! It's too late to release now! You're going to have to ride this one out, Donnell! More weight shift! Well, we didn't plan it, but it looks like we are going to find out real quick if the bridle line helps bring the glider back around where it belongs or tries to bank it over the wrong way into a lockout. Here's hoping your theory's right!
WOW! I'll say it brings it back around! It's already reversed its direction and started turning back to the right! But it's turning too fast! Quick, shift your weight back to the left before it overshoots. It's STILL turning. You'd better correct some more! It's overshooting - turning too far. More correction! There, it's starting to slow its turn. Better stop correcting or we're going to repeat this whole thing.
YEP, there she goes, reversing her direction too fast and turning back to the left. Donnell you are over-correcting. You better slack off and let the glider do more of the flying before this oscillation gets completely out of hand! But it's turning too far! The bridle line is hitting the flying wire again! There's the reverse! Now we're going back to the right. We've got a long way to go before the line touches on the left, so we can afford to relax and let the glider find its neutral position.
AH, there we go. Things have pretty well stabilized now. UH OH! In this downwind turn, we've let the towline grow slack. This is certainly no time to try flying further downwind to tighten it up, or to slow down and chance stalling an unfamiliar glider. We'd better just go ahead and land. The car has stopped, that's good. We're still over the runway. Better turn the glider into the wind - this is no time to practice a crosswind landing.
SECOND FLIGHT
The previous flight lasted about 50 seconds and reached an altitude of about 100 feet. We had used up only about a fifth of the runway, so we decided to start the second flight from where the first flight ended. Within a few minutes we had everything ready to go. The second flight went something like this:
All right, Donnell, you did pretty good on the last flight, let's make this one even better. Is everything ready? Yep! Then give the GO signal! Now hold back, take a couple of steps, and we're airborne. Everything's looking good. Be careful not to get too far to the left or the glider might do like it did last time and try to turn to the left, starting another over-control oscillation. Yes, that's right, let the glider drift slightly to the right - downwind.
Watch out! You're over-controlling again. Relax and let the glider stabilize. That's better. The climb rate is just about right. Altitude is about 200 ft. Everything seems to be going good. Watch it! You're over-controlling again. Relax! That's better.
WHAM! What's happened? Something broke! The glider's out of trim! Oh, it's nothing - the keel latch just released prematurely. But the nose is too high and the glider is trying to climb too fast. The towline force is increasing! Pull the bar in FAST! Uh Oh, too late! You broke the weak link!
...
Say, except for breaking the weak link that was a pretty good flight. With a little more practice, you might actually learn to fly this machine.
THIRD FLIGHT
It was four days later, Saturday, before I had another chance to fly my new Gemini. This time the winds were NE at 8 to 10 mph. Instead of going back to the County Airport, we went to an alternate airfield which we call "South Field". A portion of this WWII airfield was donated to the county a few years ago by the US NAVY. The rest of the field is still part of the Kingsville Naval Air Station. A barbed wire fence runs through the middle of the field separating the two parts. The only time we can fly here is when the NAS is not operating and the jet trainers are not flying.
The main reason we decided to fly here this time was that we could tow beginning flyers directly into the wind here but would have had to tow them crosswind at the regular site. Before I flew my Gemini, we had a training session where Mike Green made 18 short flights up to about 12 feet using my old standard Rogallo. After Mike finished, we set up the Gemini and the full 600 foot towline for my flights. The first of these flights went something like this:
The wind is coming straight in at about 8 mph and everything is ready to go. If we're careful, this should be a better flight than either of the two previous ones. All right, Donnell, give the GO signal and let's go. Keep the wings level while the towline under the base tube lifts the glider with its nose high. Tension's building up, let's take a few slow steps. Glider's flying. Faster now and we're airborne.
Everything's fine. This time let's remember not to overcontrol this thing. Just swing your feet to make minor course corrections. Nope, that's not quite right. Try again. Watch out, you are over-controlling again. Let the glider stabilize itself. What's this? We're flying sideways! Say, Donnell, apparently part of your problem has been a failure to recognize a YAW when you see one! There now, the glider has made its own yaw correction and is flying straight again. It's going to take a little more airtime to get used to this yawing phenomenon and make the proper control responses. Your old standard tracks so well you've never had to learn about proper yaw control. Oh well, it's going to be fun learning.
Looks like we're reaching the 250 foot mark. Better watch that auto-release line lest it surprise you with another premature release. Yep, it's tight. We're likely to have a premature release at any time now. Be ready, just in case! But the van is nearing the end of the runway, so we're going to have to release pretty soon anyway. Let's do it now before it releases itself. There, we're free.
FOURTH FLIGHT
Good takeoff! Everything seems under control. The climb rate is about right (faster than the last time). OK, let's try getting the feel of this yaw control. Man, that's WEIRD! Flying in one direction while the glider's pointing in another. It's somewhat like crabbing in a crosswind, but more temporary. Reminds me a little like a fish wiggling its tail while swimming through the water.
...
If the slight crosswind blows the line to the left, things will be all right. If not - well, we'll know pretty soon. In any case, we better assume the line does not snag and start setting up our landing approach. That ground is coming up pretty fast!
...
Apparently the towline never snagged, but the drag of the parachute on the asphalt may have pulled back enough on the bottom of the control bar to prevent me from flaring properly with my hands so high on the downtubes.
...
Right now I am waiting for my knees to heal, and I plan to repair the glider as soon as possible. At that time I'll be able to see whether or not any more damage was done. But regardless of whether or not there was any additional damage, one thing is certain: this fourth flight is the last flight I'll make in my new Gemini. It's not NEW any more.
I was on vacation and had my own winch with me. I picked up a good friend and pilot in Chicago and drove up there to see what flying was like in my home state. No one was there! The tow road was a muddy bumpy lane. I was expecting abandoned runways, because this was a WWII airforce base!
It was a big disappointment to find no one to talk to, no pilots to shake hands with. Great homecoming. I had to teach my friend to work the winch. A couple sledders ensued just to say Been There, Done That.
Years later, I made the trip again. This time I went to Whitewater to meet pilots and fly. Another disappointment. Brad K was a real ... The hospitality was nonexistent. The pilots all had their own agendas, too. The Native Son was devastated. And I grew up believing Wisconsin was a wonderful, friendly place.
I do love the city of Chicago, but I have not flown in Illinois. So very sorry to hear about Arlan Birkett and about the Chicago aerotow site closing.
Come on down and I will teach you to platform tow.
Best regards,
John
(Arlan Birkett, Jeremiah Thompson - 2005/09/03. High tug, stall following weak link failure.)
Peter Birren - 2005/09/22 19:11:32 UTC
Nothing personal but I'll pass on platform launching. I've thoroughly convinced myself that platform is just shy of aerotow-risk level. What spooks me is the high speed (35 mph) that close to the ground. Broken ribs and more from a blown aero launch drove that point home for me.
John Woiwode recently wrote privately:
"Static towing is the safest by far. I wouldn't be chomping at the bit to change, you guys are doing it right as we speak.
"Regarding my accident: in just the blink of an eye I very nearly died!! I still can't believe how fast it all occurred; I've been in lockouts before and always been able to correct or release, indeed had corrected a drift to the right and brought the glider to center comfortably before..."
So I'll stick with foot-launched static tow - or even behind a payout with a thousand feet of line out - but not platform. This old dog doesn't care to learn a new trick.
Gustav Kühn - 2005/09/22 22:32:42 UTC
Capetown
Platform/payout winch is an accident waiting to happen. Been there, done that, have the brown stains to prove it. Static line is the best, payout WITH a hundred meters of line rolled out is OK. But I'm no guru, even so, I stick to what I know best.
Actually met John Woiwode here in South Africa a while back, how is doing now?
Peter Birren - 2005/09/23 00:37:21 UTC
Me, too. That's why I promote and stick with foot-launched static line.
Here's a note from him.
I want to thank you for your thoughtful best wishes and kind words. I remember well the great crew at Bong and the competent tow pilots I flew with there.
If you have any questions on the accident or my condition, I'd be pleased to try to answer them. I am still in the hospital in Salt Lake City, with hope to be able to stand and walk within the next three weeks. With some luck they will discharge me then, and I'll be able to do the rest of the long recovery as an outpatient, closer to home.
He mentioned in another post how the doctors told him it was his "crumple zone" which saved his life. His legs/ankles are really messed up.
Gustav Kühn - 2005/09/23 07:23:52 UTC
The safest system is the one with the least amount of variables, and that is foot launch static line. Go on, make a list of what has gone or can go wrong on all the different systems and see which one is the shortest.
Peter Birren - 2005/09/23 15:48:43 UTC
The accident is fully detailed in the Oz Report. High points include:
- newer driver
- no observer
- modified glider with more anhedral
- low altitude lockout
The safest system is the one with the least amount of variables, and that is foot launch static line.
There have been several postings lately regarding the safety of various forms of towing. Several authors seem to agree with the conclusion that static line towing is the safest, aerotowing is the most dangerous, and platform towing is somewhere in between. Various reasons were given for those conclusions, but the bottom line was said to be the statistical records of injuries and deaths for the various forms of towing. I for one would love to see those statistical records. Without such data I can only surmise that every form of towing has its advantages and disadvantages which makes each safer than the others when performed properly under its respective advantageous circumstances.
In fact, I would even like to see reliable statistics as to how many pilots tow which ways in various parts of the country and how that pattern has changed over time. Without such data, I can only surmise that aerotowing has grown at the expense of platform towing while leaving the static line numbers relatively unchanged. Any comments?
And finally, in an effort to improve the safety of my preferred method of towing, I would appreciate any comments regarding the following advice to anyone who platform tows:
1. Weak link
Many pilots platform tow with a weak link that is much too strong. Make certain you are towing with the proper strength weak link. Then you will also be certain that you are not inadvertently towing with too much tension. I use #18 mason twine (nylon) purchased in the hardware department at Wal-Mart. I double it and tie the two ends together with a simple overhand knot. My students (regardless of their weight) tow with this two-strand weak link while I double it again (four strands) when platform towing because I have more experience and want to climb faster with a higher tension setting. If you want to get really precise, keep testing various weak link configurations until you find one that will support your weight when you hang but will break when you bounce.
2. Tension setting
Many pilots platform tow with too great a tension that can result in a dangerous nose-high attitude. The proper tension setting for an inexperienced tow pilot is the maximum that will allow you to manually pull line off the drum while the truck is stationary. Too much tension and your feet will slip on the ground, too little tension and you will climb too slowly. Another test is to hang from the glider, pull yourself forward as far as possible, wind up the line on the drum, set the tension, and see if your weight pulls the line back out. If it does, your tension is too low. If it doesn't, then see if you can push yourself backwards without too much effort and pull the line out. If you can't then the tension is too high. Once you have determined the correct tension, read your gauge to see what the correct setting should be. You can then use this setting in the future. However, remember that the gauge setting is not always a reliable indicator of towline tension (the brakes can be rusty). Therefore, re-check the payout tension from time to time to verify that your gauge is still working correctly.
3. Glider nose angle
If your glider is nose high or nose low while sitting on the platform, it may cause undue stress on the glider and adversely affect the launch. The proper nose angle is such that the glider slices through the air with minimum frontal area. The easiest way to determine this angle is to hang prone from the glider and adjust the nose angle until the control bar is in the normal trim position (generally about shoulder level).
4. Hook in
Make sure you attach the towline below the base tube and that your release line from your shoulder to the Linknife (or other reliable release) is the correct length. It must be long enough so as not to cause a premature release and short enough that you can release with a single pull of the line regardless of whether the towline is forward (as during launch) or downward (as when topping out). Pull your body forward, take up slack, and tension the drum. Finish going through the check list located in front of you on the platform deck as you taxi and prepare for launch. (I'm skipping a lot of things here.)
5. Launch speed
You should have an unobstructed airspeed indicator positioned such that both the driver and the pilot can see it (such as at the top of a vertical rod attached to the front bumper of the truck). If this is not possible, use two unobstructed airspeed indicators. If this is not possible, use one the pilot can see. If this is not possible, use one the driver can see and have him honk the horn when the proper airspeed is reached for launching the glider. If this is not possible, measure or estimate the wind speed, subtract that value from the proper launch speed, and have the driver honk the horn when the truck's speedometer reaches that value. The proper airspeed for platform launching is approximately 10 mph faster than the stall speed of the glider. For many hang gliders this is about 30 mph.
6. Prepare to release
The most dangerous phase of platform towing is the launch. Things can go wrong very fast because you are towing on a very short towline and making a rapid transition between platform and flight. Therefore, immediately before launching, make sure your release line runs from your shoulder, between your thumb and the base tube, and to the Linknife. This allows you to release very rapidly because you do not have to hunt for the release line before releasing. You simply grab the line already in your hand, pull it away from the release to cut the weak link, and grab the base tube again to maintain control of the glider. This can all be done in less than one second - two at the very most.
7. Launch
Many pilots use the four stage launch sequence: CREW READY? (make sure everyone is alert and ready to go), GO TO CRUISE (accelerate through any gear shifts to just below launch speed and hold the speed steady), ACCELERATE (accelerate through the launch speed to about 5 mph above launch speed), and CLEAR (pilot launches at launch speed, truck accelerates to about 10 mph above launch speed). Personally, I prefer to omit the GO TO CRUISE stage and simply ACCELERATE from the start, launching when the proper launch speed is attained. If something goes wrong and I cannot release as planned, I shout "ABORT, ABORT" and the driver slows down to a complete stop.
8. Emergency release
If the weak link breaks, you should already be pulling in to maintain airspeed over the hump and then prepare to land on your feet. If a gust lifts one wing more than the other, you should release immediately, level the glider, and land. If you fail to climb out, if you begin to over-fly the truck, if anything else goes wrong, or if you simply get the feeling that "something is wrong here", you should release immediately and prepare to land on your feet.
9. Climb out
Once the initial launch is over, it is time to relax and enjoy the tow. You start by relaxing your pull on the control bar so it goes from waist (to maintain high speed and avoid stalling) to neutral or shoulder height (to go to trim speed and climb faster). Then drop the release line from under your thumb (so you do not accidentally release yourself while shifting your weight to correct for strong wind gusts). All of this can be done within five seconds after launch. Then simply keep the wings level (so the glider will stay on track with the towline even if there is a crosswind causing it to drift to the side of the runway).
10. Release
Once the truck runs out of runway, you enter a strong thermal, or you top out of the climb, then pull in on the control bar (to regain airspeed and avoid a stall) and release from tow. Continue the rest of the flight like any other free-flight activity.
Any comments?
Martin Henry - 2005/09/27 05:00:02 UTC
Donnell, Great to see you're posting. I concur with comments. I concur with comments. I've been platform towing for over fifteen years and well appreciate that aviation does have its risks. I also know that if you do it "Right", platform towing can be an excellent method of getting our wings into the air.
Things go wrong when we do things wrong. The big mistakes include too strong a weak link, too high a tension, poor procedures, poor releases, and poor understanding of how things should work.
A soft tow, a proper weak link, and a good system will get you safely into the air.
I laughed when I read your comments about how you changed the typical launch commands to a three step command. For years I used the "go to cruise". After a while I too dropped it and simplified the procedure.
I use a slight variant on your "Crew Ready". I go with a short checklist that double checks the ready to tow setup:
Check Pressure, set 150? (on my system)
Road Clear?
No Air Traffic?
No Dust Devils?
Ready to Tow?
My driver will then answer my questions. Then I call for (when ready) Go to Cruise and Accelerate (all one statement).
In our system we do not use an observer. Our driver uses two big convex mirrors to monitor the tow. Our winch has an emergency dump.
If used, the operator is trained to dump the pressure and "play" the tension to ease line off of the drum. (A hook knife if used to back up as the final solution.)
One other critical element in our system is "Auto Tension". The line tension is governed by a spring that predetermines it. Even if the pilot calls for more the system cannot be overloaded. The most common mistake I have witnessed that a pilot will make when towing from a platform system in "big air" is calling for more pressure in sinking air. Pilots need to understand that a "safe tension" should not be exceeded just to compensate sinking air. Remember, too much tension is not a good thing!
One last thing, we never use a "non-pilot" to run the winch. I personally feel only a pilot can truly understand towing. An experienced Pilot/Winch operator is capable of recognizing when something is going wrong and how to deal with it. This is a very important aspect of our towing setup and without question has contributed to our years of trouble free towing.
Jim Gaar - 2005/09/27 14:21:40 UTC
It's how I started and soloed and how my first Instructor, Ron Kenney, has been doing it for over 25 years, hundreds and hundreds of times without and accident.
Follow the rules and procedures EVERY TIME and platform launch is as safe as any method out there.
Bill Finn - 2005/09/28 16:08:07 UTC
I also learned to tow via Platform Launch with Ron. It was a good system and great fun. My prior towing experience at the time (1990) had been limited to static line towing.
Comparing the two, I think static line towing is a bit more efficient... higher tows per distance traveled on the ground. Seems like PL towing requires a higher degree of tow vehicle driver skill to keep the vehicle speed in the "sweet spot" where you get the best rate of climb over a minimum distance traveled. Seems like it's easy to over-speed the PL tow vehicle and just pay out line without getting a good climb rate. Of course, if your tow road is long enough, it doesn't make that much difference.
I also think that all HG towing systems, Aero, Platform and Static-line can be as safe as you want them to be. You just can't allow yourself to get lax. It's serious business!
Bill Bryden - 2005/09/27 15:34:47 UTC
I tabulated all the USHGA accident data and wrote the accident report column in the magazine for about three and a half years. Up through that time, there was no statistical data compiled by the USHGA to show any statistical comparison of the various methods of towing. I am unaware of any other organization that compiled good data to that effect. Accident report information and magazine articles really dropped off after my tenure and I seriously doubt any analysis has been performed since.
I did perform an analysis of fatality rates a while back with towing included and towing excluded from the data. The fatalities per 100,000 participants was actually a wee bit better when the towing data was included. This was NOT the article in HG magazine 4-5 years ago that someone else wrote after getting some of the raw data from me. They then specifically excluded some data and made some overly generous assumptions so the analysis was quite flawed presenting in my opinion a very inaccurate (and overly optimistic) picture of HG fatality rates.
Trying to separate the forms of towing was never done because the USHGA's data was sufficiently sparse to not be possible to draw any statistically valid conclusions.
However, as I remember the data I saw, a strong percentage of the serious platform launch accidents were a result of attempting to launch with a control bar restraining device still attached to one side of the control bar. The static line had a lot of ground loops and similar launch accidents but the consequences were usually not severe. Unfortunately there were still a number of fatalities usually lockout type events when the tow line pulled against the control frame one way or another. The aerotow fatalities were often issues with a launch cart or low level control/lockout issue. While high tow tensions can exacerbate a problem, I don't recall (doesn't mean it didn't occur) any accident in the last 15 years were high tension was a cause or a significantly contributing issue.
The safety "impressions" some people form when hearing about several accidents, I doubt are often tempered by the denominator of the equations - how many people or how many tows of that sort have actually occurred in a year. Recently, we have heard of a couple aerotow fatalities, but if 80% of the towing going on in the US is aerotow, then of course that is to be expected. And while the USHGA tried to survey and get a little data about towing a while back with the annual surveys, the data wasn't very good and didn't capture just how much of each was taking place. We don't know if aerotowing comprises 60%, 80% or 90% or what of the number of tows performed each year. We did know it is a lot several years ago by looking at who purchased one month memberships and how many.
The real bottom line, I don't think the data exists to make statistically valid claims that one form of established towing is dramatically safer than the others.
Bill Bryden
Towing Aloft
Brendan (BJ) McCaskill - 2005/09/27 22:29:07 UTC
I've been loving this discussion and just have to throw in my two bits worth, if a little off topic.
Stats on accidents by towing type would be interesting, but I'm not sure they would be valuable. I even think they would be seriously misleading. At the root, most aircraft accidents have little to do with aircraft types or launch methods. Most trace to pilots' personalities - i.e. the five fatal flaws: Macho, Anti-Authority, Invulnerability, Impulsiveness, and Resignation. This is straight out of the Transport Canada (any country's) human factors guide.
You see them all the time: the "no check listers", the macho "don't need any damned safety observer" guy, the "I'll launch in anything" man, "Do or die - rather die than stand down" types, Mr. "close eyes and pull launch trigger" type, etc. Here stats would be useful - if impossible - to collect.
There may be as little point in comparing launch methods as there is comparing adventure sports. It's the same kind of people that are hurt regardless of what they are doing, platforming or aerotowing, sky or scuba diving. Regions with the best attitudes and leadership will have the fewest accidents. Example and leadership of senior pilots in a given region will have a much greater impact than any technical details.
It ain't what you do, it's how you do it!
Doug Beckingham - 2005/09/28 02:35:39 UTC
Do and don't agree. While the human factors have to be taken into account, having the stats available to those teaching, forming policy, and developing systems is a hugely valuable tool. Much like the weakest points (causing accidents) are in fact pointed out by finding the links in the chain that are in fact the weakest. If the chains that we make always break at the third link in from the far end then it is time to examine how we make, check, observe, and develop that link. Eventually we have a stronger, more flexible, and often lighter chain sometime later - this is good. Sometimes something simple, like forming the observation itself, can lead to an equally simple solution or repositioning. I know that I want to continually improve my understanding, viewpoint, and communication in the sport. Anything that helps this I then welcome with open arms. Keep the viewpoints up.
Brendan McCaskill - 2005/09/28 17:49:24 UTC
Point entirely valid. I agree.
To clarify my own point a little better, I believe that the human factors overwhelm technical factors to the point where looking at the latter in isolation from the former is dangerously deceptive and a waste of resources. Gross statistics mean so little.
If studying traffic accidents we never hear them rationally blamed on the car or the type of road. Cars and roads are, and should be, studied but application of such studies is usually aimed at finding new ways to idiot proof them against, guess what?
And the dissection...
Donnell Hewett - 1982/11
You're hooked in.
YOU may be - I'm not. That's the reason you've launched unhooked and I haven't.
You're committed now, so you better keep the glider positioned properly while the vehicle gains speed.
Right Donnell, 'cause a release you can actually USE during a critical flight situation has never been an element of the Skyting Criteria for "safe" towing.
The glider is crabbing sideways over the runway as it should in the crosswind situation.
Yeah. You REALLY wanna keep the glider right over the runway with a 10-15 mph 60 degree left crosswind.
WHAT'S THE MATTER? The glider wants to turn left!
NO!!! The glider wants to turn left??? What could POSSIBLY be causing that to be happening?
You better shift your weight to the right. Hey, it's still turning left! Shift your weight some more! Watch out, the keel line is touching the right flying wire! It's too late to release now! You're going to have to ride this one out, Donnell! More weight shift!
YEAH!!! Shift that sucker!
Here's hoping your theory's right!
WOW! I'll say it brings it back around!
Yeah, the sideways tow tension pulled your glider back in line. No other explanation remotely possible.
We've got a long way to go before the line touches on the left, so we can afford to relax and let the glider find its neutral position.
No, no, NO!!! You gotta keep it over the runway. Remember?
The car has stopped, that's good. We're still over the runway.
Good job. I'm proud of you.
Be careful not to get too far to the left or the glider might do like it did last time and try to turn to the left, starting another over-control oscillation.
What it was starting was a LOCKOUT.
Yes, that's right, let the glider drift slightly to the right - downwind.
Just slightly though. Remember - You gotta keep it over the runway.
The climb rate is about right (faster than the last time). OK, let's try getting the feel of this yaw control. Man, that's WEIRD! Flying in one direction while the glider's pointing in another. It's somewhat like crabbing in a crosswind...
Perhaps because you ARE crabbing in a crosswind? Maybe it feels weird 'cause Mother Nature is trying to tell you something.
Peter Birren - 2005/09/22 19:11:32 UTC
Nothing personal but I'll pass on platform launching. I've thoroughly convinced myself that platform is just shy of aerotow-risk level.
Yeah, Peter, the list of things of which you've convinced yourself over the course of your hang gliding career is absolutely astounding.
What spooks me is the high speed (35 mph) that close to the ground.
What spooks the hell out of me is going half that speed that close to the ground. (Mike Robertson - Did I ever remember to thank you properly?)
Broken ribs and more from a blown aero launch drove that point home for me.
So Peter, what idiot thing did YOU do to join the microscopic minority of bozos who've been able to fuck up an aerotow dolly launch? Suggested choices include:
- not speed testing it for stability before going live
- giving a thumb's up on soggy ground with flat tires before bracing yourself
- driving it into an armadillo burrow (substitute woodchuck if necessary)
Or did you come up with something all by yourself that the idiots doing many thousands of tows per season at the flight parks haven't thought of yet?
That's why I promote and stick with foot-launched static line.
And 0.8 G weak links as lockout and drag protectors and releases you can't get to but will blow you off tow when your nose is straight up.
John Woiwode - 2005/09
Static towing is the safest by far. I wouldn't be chomping at the bit to change, you guys are doing it right as we speak.
Regarding my accident: in just the blink of an eye I very nearly died!! I still can't believe how fast it all occurred; I've been in lockouts before and always been able to correct or release...
I got news for ya John.
- You WERE - for all intents and purposes - static towing when got so brutally slammed in.
- If you were able to correct you weren't in a lockout
- The fact that you think you can correct in a lockout totally discredits your comments that you've been in lockouts before.
- This one was a LOCKOUT - which you totally flew yourself into.
...indeed had corrected a drift to the right and brought the glider to center comfortably before...
I got more news for ya John. The drift to the right WAS the correction. But you thought you knew better and overrode it.
Peter Birren - 2005/09/22 19:11:32 UTC
So I'll stick with foot-launched static tow - or even behind a payout with 1000' of line out - but not platform. This old dog doesn't care to learn a new trick.
Big surprise.
The trick that John failed to learn was pretty obvious to ten-year-old Chinese kids flying kites thousands of years ago.
Gustav Kühn - 2005/09/22 22:32:42 UTC
Platform/payout winch is an accident waiting to happen.
Yep, very patiently. Tons of action over the course of a quarter century and no good examples yet.
Been there, done that, have the brown stains to prove it.
Yep, you just blast straight up off the back of the truck REALLY FAST! Very scary.
I stick to what I know best.
Yep, that's what's always made hang gliding such a great sport. Everybody sticking like barnacles to what he knows best - and the contradictory evidence and experiences be damned.
John Woiwode - 2005/09
I remember well the great crew at Bong and the competent tow pilots I flew with there.
No.
Gustav Kühn - 2005/09/23 07:23:52 UTC
The safest system is the one with the least amount of variables, and that is foot launch static line. Go on, make a list of what has gone or can go wrong on all the different systems and see which one is the shortest.
Yeah Gustav, let's make a couple of lists of REAL - versus imaginary - problems with foot launch static and platform launch towing. We'll assume that we have halfway competent people running and flying things and that the equipment wasn't designed by total assholes and gets maintained once in a while.
Foot Launch Static
- Since the pilots, drivers, observers, and assistants absolutely refuse to comply with the regulation that the connection be verified JUST PRIOR TO LAUNCH, hook-in failures are common as dirt.
- Pilots:
-- start with their hands on the downtubes and have crappy control of the glider
-- launch at the whim of a driver a quarter mile away
- Once things start rolling the pilot is incapable of aborting the tow.
- Pilots:
-- hafta run
-- are unable to control:
--- pitch
--- roll
-- get:
--- hit with:
---- crosswinds
---- tailwinds
--- dragged
-- launch with little reserve airspeed
-- hafta rotate to prone and shift their hands to the basetube after they've been airborne for a bit before they can get good control of the glider
- There's a much greater probability of the weak link failing.
When gliders get turned away from tow the rate of increase in tension goes through the ceiling and lockouts happen fast and hard.
Platform
- The winch can lock up and convert the tow to static.
Neither mode allows the pilot to release in an emergency but only the foot launch static towers ever need to.
Peter Birren - 2005/09/23 00:37:21 UTC
The accident is fully detailed in the Oz Report. High points include:
- newer driver
- no observer
- modified glider with more anhedral
- low altitude lockout
What about the fact that he deliberately flew the glider to the edge of lockout position before he got hit with Problem Number 2?
Donnell Hewett - 2005/09/27 02:35:06 UTC
I for one would love to see those statistical records. Without such data I can only surmise that every form of towing has its advantages and disadvantages which makes each safer than the others when performed properly under its respective advantageous circumstances.
We're never gonna get great statistics on hang gliding so how 'bout we start looking at what we have and try to start learning something useful from it - for something new and different?
Many pilots platform tow with a weak link that is much too strong.
Too strong to WHAT? Protect the pilot from getting out of control, stalling, locking out?
If you go by the definition of a weak link from REAL aviation... Are we breaking gliders?
What's the evidence upon which you're basing that statement? Can you cite a single instance of a platform tower having a problem due to an overstrength weak link?
Then you will also be certain that you are not inadvertently towing with too much tension.
Too much tension to WHAT? If the tension is something making the guy in the glider uncomfortable is there someone pointing a gun at his head making him stay on tow?
My students (regardless of their weight) tow with this two-strand weak link...
Great. So what's the flying weight range of your students? You're flying the light ones at higher Gs than the heavy ones. Are the light ones having more problems?
...while I double it again (four strands) when platform towing because I have more experience and want to climb faster with a higher tension setting.
Which obviously means that if any of your students - especially the ones heavier than you - find themselves going up in steep climbs the weak link is gonna blow. Are you sure you've thought through all the implications of that?
If you want to get really precise, keep testing various weak link configurations until you find one that will support your weight when you hang but will break when you bounce.
Do I get to wear my harness with the parachute in the container?
How many Gs is that gonna be if I decide to take a glider with me when I'm towing?
What's this precision gonna do for me?
Many pilots platform tow with too great a tension that can result in a dangerous nose-high attitude.
So if you set your tension properly you CAN'T get into a dangerous nose-high attitude? How 'bout Brad Anderson and Eric Aasletten? They got into nose-high enough attitudes dangerous enough to kill them when and because they lost the tow. And they were on payout winches so the tension was constant and probably in the ballpark of 140 pounds. So they probably only weighed 120 pounds and should've been using precision 120 pound weak links to prevent that from happening.
The most dangerous phase of platform towing is the launch.
The most dangerous phase of ALL towing is the launch. One of the two most dangerous phases of all FLYING is the launch. And since the other one is pretty much out of the towing equation...
Things can go wrong very fast because you are towing on a very short towline...
So are we seeing people actually paying penalties for being on short towlines in the first few seconds of platform launches?
...and making a rapid transition between platform and flight.
Are we sure this "rapid transition between platform and flight" is all that problematic? The Navy seems to favor that approach for getting F-18s off of ITS platforms.
Might the Skyting "gradual transition to tow" actually be more of a sticky wicket?
Al Hernandez
28th and 29th I will be up in Kingsville, at the Kleberg County Airport about 8 am. I will be training with the Doc. He will be having lessons there Saturday, depending on weather conditions. Will be towed up with a winch - this will be my first tow. Have just been doing foot launch, will get some airtime in on those days.
I had to stand like a post, and not move at all once the truck took off at 25 mph with one foot in front of the other, and I am still standing in the same place leaning back, with the payout feeding me line, and there is a strange feeling, odd feeling to being pulled by the payout.
Then I take the first step to the run, and I am now running 25 mph, I am thinking, oooOOOOH SHIT, hope I don't have to run that far, hoping the HG gets lift so I don't have to run no more... My F-A running down the runway like a rocket. There is no wind, I have the right angle of attack, the HG is up, but still not enough lift for the pilot.
I can't reach my CUT line 'cause I have both hands on the downtubes, and if I let go of the Coke bottle grip I will crash.
I feel like pushing the HG into the air, or jumping up so it can lift, but I do not - that would make my situation worse.
I feel I am about to fall into the asphalt face first and crash, I am at my run limit, and feel I can not take another step. Still the glider is not lifting me.
The winch operator lets go of the pressure of the payout winch, my run comes to a jog, and to a stop. I drop to my knees.
Therefore, immediately before launching, make sure your release line runs from your shoulder, between your thumb and the base tube, and to the Linknife. This allows you to release very rapidly because you do not have to hunt for the release line before releasing. You simply grab the line already in your hand, pull it away from the release to cut the weak link, and grab the base tube again to maintain control of the glider. This can all be done in less than one second - two at the very most.
Lemme show ya what can happen in a second while you're simply grabbing the line going from your shoulder to your Linknife and cutting the weak link in the REAL world when people are starting to keep score.
Imagine if you will, just coming off the cart and center punching a thermal which takes you instantly straight up while the tug is still on the ground. Know what happens? VERY high towline forces and an over-the-top lockout. You'll have both hands on the basetube pulling it well past your knees but the glider doesn't come down and still the weaklink doesn't break (.8G). So you pull whatever release you have but the one hand still on the basetube isn't enough to hold the nose down and you pop up and over into an unplanned semi-loop. Been there, done that... at maybe 200 feet agl.
You play that idiot game more than once or twice and you won't be playing it again.
...and grab the base tube again to maintain control of the glider.
Lemme 'splain a few things about MAINTAINING control of the glider.
You need TWO hands FIRMLY on the basetube - ALL the time - to MAINTAIN control of the glider.
And when you:
- are on tow you need two hands firmly on the basetube all the time about twenty times more than you do in free flight.
- NEED "to release very rapidly" FROM tow you need two hands firmly on the basetube all the time about a thousand times more than you do in nothing imminent tow flight
So this business being able to pull a string tied to your shoulder while MAINTAINING control of the glider is a bunch of dangerous bullshit - as is Peter's idiot configuration. And that's been understood by the small minority of people in hang gliding who've had a clue as to what they were doing for a very long time.
Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974
"Never take your hands off the bar." - Tom Peghiny
And back then - for all the other shortcomings of the day - they invested in the quality equipment to make that a working reality.
If something goes wrong and I cannot release as planned, I shout "ABORT, ABORT" and the driver slows down to a complete stop.
How often does that happen and why?
If the weak link breaks, you should already be pulling in to maintain airspeed over the hump and then prepare to land on your feet.
Assuming that everything else is just hunky-dory - as it ALMOST always is. Otherwise the ground may come up long before the hump becomes doable and you may land on your face really really hard. But why are we talking about this anyway? Won't your precision weak link always hold unless you're rolling too hard, climbing too steeply, locking out, being towed too fast, anything goes wrong?
Why is this issue being discussed under the heading of "emergency release"? It's not a release. Is it an emergency? If so, is there anything you can think of doing to minimize the frequency of these emergencies? What's your current frequency anyway? Still 25 percent?
If a gust lifts one wing more than the other, you should release immediately, level the glider, and land.
Right. Obviously this is the sort of problem you're ALWAYS gonna be able to to fix on the way down and never on the way up. Take a clue from the General Aviation people. Whenever they get rolled during takeoff they kill the engine and glide to a safe landing. And if you're the driver and you see this happening and the pilot isn't following proper protocol... You have a dump lever don't you?
If you fail to climb out, if you begin to over-fly the truck, if anything else goes wrong, or if you simply get the feeling that "something is wrong here", you should release immediately and prepare to land on your feet.
Right. If you're not climbing out right away then cut power IMMEDIATELY. Can't go wrong with that approach. WHATEVER is going - or you think might go - wrong, kill the engine. Listen to your inner voice - a rational assessment of the situation can always wait. Hell, nowadays it can almost always be analyzed frame by frame on YouTube by your friends.
And ALWAYS prepare to land on your feet. Don't even DREAM about rolling or bellying in. ALWAYS rotate to vertical, get your hands way up on the downtubes, and get ready to whipstall that baby at just the right instant no matter what the cost. Even if staying prone at an airport is a no brainer you always need to practice a no stepper so you can safely land in cornfields and narrow boulder-strewn riverbeds whenever you feel like it.
Then drop the release line from under your thumb (so you do not accidentally release yourself while shifting your weight to correct for strong wind gusts).
Meaning, obviously, that you're launching in a configuration in which you almost certainly WILL auto-release when the shit hits the fan during what you correctly identified three paragraphs ago as the most dangerous phase of the tow. Did you ever bother to read the Anderson and Aasletten fatality reports?
All of this can be done within five seconds after launch.
So by five seconds into the tow you're golden, there will never be a situation in which you need to release rapidly while pretending to maintain control of the glider, and you can afford to go on a hunting expedition for the lanyard?
Then simply keep the wings level (so the glider will stay on track with the towline even if there is a crosswind causing it to drift to the side of the runway).
So 81 days after John has needlessly destroyed his life as he knew it - nearly 23 years after those fiasco first tows on your new Gemini - we're getting around to the real issue here. Anybody in this crowd paying attention? Maybe it would help a little to lose the parentheses.
Martin Henry - 2005/09/27 05:00:02 UTC
Things go wrong when we do things wrong. The big mistakes include too strong a weak link, too high a tension, poor procedures, poor releases, and poor understanding of how things should work.
Can you cite a single instance of an allegedly overstrength weak link EVER being an issue in a platform launch? Remember, we're talking payout winch here. Nothing? OK, I'll open it up to ever in the history of modern hang glider towing.
Why is too high a tension a big issue? If the pilot's feeling excessive tension is there something forcing him to stay on tow?
Is anyone in ANY kind of surface towing using a GOOD release?
Steve Kinsley - 1996/05/09 15:50
Personal opinion. While I don't know the circumstances of Frank's death and I am not an awesome tow type dude, I think tow releases, all of them, stink on ice. Reason: You need two hands to drive a hang glider. You 'specially need two hands if it starts to turn on tow. If you let go to release, the glider can almost instantly assume a radical attitude. We need a release that is held in the mouth. A clothespin. Open your mouth and you're off.
Has ANYTHING improved since then?
4. Name some people who have good understandings of hang glider towing. I'll bet you can count them on the fingers of one hand. On that topic... Did you have a comment on the John Woiwode incident?
A soft tow, a proper weak link, and a good system will get you safely into the air.
What the hell does a "proper" weak link have to do with getting you safely into the air? If it's held, it's gotten you into the air. If it hasn't, it hasn't. If you're in the air and a "proper" weak link is holding, does that mean you're safe? If John Woiwode had been using a "proper" weak link would he have been safe?
Exactly what IS a "proper" weak link anyway? Is it the same for all gliders like in aerotowing?
Is it the same as a "precision" weak link - exactly the weight of the harnessless pilot?
Are we ever gonna hear anything about Gs it this conversation?
A hook knife if used to back up as the final solution.
How many times has that been of use and why?
Pilots need to understand that a "safe tension" should not be exceeded just to compensate sinking air. Remember, too much tension is not a good thing!
Define "too much tension". Is there an ideal tension appropriate for all situations? In there such a thing as too LITTLE tension? You don't really need to answer that last one 'cause I've BEEN crashed by an idiot who reduced tension on me for absolutely no reason when I needed the opposite.
One last thing, we never use a "non-pilot" to run the winch. I personally feel only a pilot can truly understand towing.
How very odd. In my experience I've found hang glider pilots completely incapable of understanding towing and I'd shoot the vast majority of them before I'd ever let them near the other end of my towline. And the only thing worse than a hang glider pilot is a tug pilot. And the only thing worse than a tug pilot is a tug pilot who's also hang glider pilot - except for Jonny Thompson.
Donnell Hewett - 1984/03
In selecting a driver, my advice is to use the BEST QUALIFIED DRIVER you have available, irrespective of whether or not he's a pilot. My wife is a non-pilot and is without doubt the best qualified driver I have ever towed behind.
An experienced Pilot/Winch operator is capable of recognizing when something is going wrong and how to deal with it.
Whatever's going on back there, I can fix it by giving you the rope.
Yeah, right.
Brendan McCaskill - 2005/09/27 22:29:07 UTC
At the root, most aircraft accidents have little to do with aircraft types or launch methods. Most trace to pilots' personalities - i.e. the five fatal flaws: Macho, Anti-Authority, Invulnerability, Impulsiveness, and Resignation.
This is an absolutely spot-on description of hang gliding culture at large and is the root of why people are maimed and killed towing. But does not address the issues involved in the individual incidents.
John, for instance, was mangled because he didn't have a clue what he was doing - not because he was oozing with any of the fatal flaws. I've known a lot of hang glider towing victims and these flaws aren't issues in anything near enough of them. If it were Darwinian evolution would make hang gliding an infinitely more pleasant environment and it's obviously streaking off in the opposite direction.
The big ticket items in hang glider towing are clueless foundation theory and the junk standard operating procedures, equipment, instructors, operators, drivers, and flyers that go along with it.
Fix the theory and instruction, shoot a few flight park operators, get rid of the shit equipment and precision weak links and the problems go away.
Doug Beckingham - 2005/09/28 02:35:39 UTC
Do and don't agree. While the human factors have to be taken into account, having the stats available to those teaching, forming policy, and developing systems is a hugely valuable tool. Much like the weakest points (causing accidents) are in fact pointed out by finding the links in the chain that are in fact the weakest. If the chains that we make always break at the third link in from the far end then it is time to examine how we make, check, observe, and develop that link. Eventually we have a stronger, more flexible, and often lighter chain sometime later - this is good.
In other words, BEEF UP THE FUCKING WEAK LINKS? Yeah, that would be a pretty good start. That's something on which we DO have pretty goddam good statistics and it WOULD be nice to form policy accordingly. Or do we need to crash a few more gliders just to make absolutely sure?
Brendan McCaskill - 2005/09/28 17:49:24 UTC
If studying traffic accidents we never hear them rationally blamed on the car or the type of road. Cars and roads are, and should be, studied but application of such studies is usually aimed at finding new ways to idiot proof them against, guess what?
But let's keep our theory and equipment as stagnant as it's been the past few decades. More sporting that way.
---
2020/09/16 18:40:00 UTC - Amended.
Tad Eareckson wrote:So are we seeing adverse yaw or similar action/reaction stuff?
Can't it be both? Wikipedia defines adverse yaw as 'a yaw aircraft movement opposite to the direction change initiated by a roll movement.' Does it matter what the cause is? I've heard a lot of explanations of what causes it in a hang glider and I'm really not sure what does. Pagen says it's because you're increasing wing loading on one side of the glider, causing that side to fly faster (until the glider's yaw stability counters it).
Tad Eareckson wrote:If we're looking at an effect of adverse yaw, is the swept wing surprised by it and in need of a couple of seconds to get its shit together and react?
Yes, according to Pagen. It makes sense to me. Hang gliders' yaw stability will cause a glider to eventually align with the relative wind but can't prevent sideslip altogether.
I don't have any experience flying airplanes for real, but I've read books on the subject and have a fair amount of experience with flight simulations. In my virtual experience, when an airplane's rudder is not used to counter adverse yaw, it responds to bank changes exactly as a hang glider does (i.e., as the video illustrates).
Tad Eareckson wrote:And I've just got a real short fuse when I hear people talking about it in reference to towing and lockouts.
I agree that adverse yaw isn't significant in towing, but sideslip and yaw stability are, and I think a lot of hang glider pilots call sideslip adverse yaw.
Anyway, I'm not going to address all of your arguments regarding why I should build my own release because it ain't gonna happen. Yes, I wish there was better stuff available, but you can't expect everyone to make their own stuff.
Here's where I stand on releases:
- I'll use the new Lookout release for my two-point primary. It may not be perfect, but you agree it's the best I can do off-the-shelf.
- I'll use one of your barrel releases as a secondary. I suspect it's the best release of its type. Yes, I'll still have to take my hand off the bar to use it, but I think the chances of me needing to use it near the ground are incredibly slim, so it's a risk I'll take. It's a lot better than what I'm currently using at any rate.
- I don't know of any options for platform launching better than what I'm currently using. One possibility might be to dolly launch with a V-bridle and use my Lookout release.
So what lengths do you recommend for secondary bridles? How about primaries? I take it I'm going to have to make these as well, as you can't buy them in those lengths, right? Is there anything wrong with the spectra rope conventionally used for these things? Regarding your aerotow configuration, you've said "there's very little chance of a primary bridle wrap". Is there less of a chance than with conventional spectra bridles? If so, how do you achieve this?
Tad Eareckson wrote:All of my releases...are weak link protected at all times.
So let's say my primary bridle wraps, the weak link on my secondary release blows, and then the secondary bridle wraps. Is there any chance the weak link on my other shoulder wouldn't immediately break? If it didn't, I'd be stuck to the line without a release (although I could of course fly with another shoulder release if that's an issue).
Tad Eareckson wrote:
Zack C wrote:I would agree that our safety record is much better than he makes it out to be.
I wasn't making anything out to be anything.
My statement wasn't written so much in regards to the FAA letter (which as I said I hadn't read much of at the time) but rather your forum posts (I've browsed the Oz Report and HangGliding.org forums for years). The best way to clarify what I meant is with an example. You've stated that we shouldn't be truck towing due to having to reach for our releases, but you admit that
Tad Eareckson wrote:So right now I don't have a great example of anyone otherwise doing things right seriously messed up by a truck tow who wouldn't have been seriously messed up if he had had a button in his hand or some kind of actuator between his teeth.
Suggesting we cease truck towing entirely implies a very grave threat, one that hasn't proven to be so big a deal in practice. That's the kind of thing I was talking about. (I'm not saying that we should wait until someone gets killed because of this before we try to change anything.)
Yeah, it can be anything. I'm starting to get out of my depth pretty fast here but I don't worry about it much 'cause - if anything - it's a glider manufacturer issue, I can't do anything about it, and I have NO complaints about the way they're doing their jobs - beyond not offering built-in releases and specifying weak links for glider models, using nylon for suspension, and shipping with backup straps.
In my virtual experience, when an airplane's rudder is not used to counter adverse yaw, it responds to bank changes exactly as a hang glider does (i.e., as the video illustrates).
Yeah, but our swept wing IS a giant rudder so we're applying it all the time whether we want to or not. (Funny that Wikipedia article says nothing about sweep.) But, I don't really know. Too much geometry, aerodynamics, and physics for my head to wrap around and balance. That's why I mostly stick to issues involving letting go of strings. Just need to be way up from a tug driver and a little down from a chimp to master everything you need in that department.
Yes, according to Pagen.
Winter fun... Whenever you reference Towing Aloft keep a pencil in your hand and start making light marks and notes every time you find a typo, inconsistency, contradiction, instance of certifiable insanity - and watch the pages blacken. There's some good stuff in there - stuff I probably couldn't have figured out on my own - but that just makes the book more dangerous because it gives credibility to all the unadulterated rot.
Anyway, I'm not going to address all of your arguments regarding why I should build my own release because it ain't gonna happen.
Those weren't arguments why you should. Those were arguments why someone like you COULD. Don't build them - but keep on looking at my photos and thinking about how things are put together. Look at my full two point system - minus the stuff in the basetube (not important) - with the spinnaker shackle (in the Cache set) for starters. And look at your starboard side VG system - cord, cleat, bottom pulley. It ain't all that tough if you want to recover the glide point all that cable crap is sucking out of your glider.
- I'll use one of your barrel releases as a secondary. I suspect it's the best release of its type. Yes, I'll still have to take my hand off the bar to use it, but I think the chances of me needing to use it near the ground are incredibly slim, so it's a risk I'll take. It's a lot better than what I'm currently using at any rate.
Assuming you dolly launch, use good equipment, preflight, set the pitch angle about right, don't do anything real stupid...
The chances that you'll require an emergency release - instant, both hands on the basetube - within striking distance of the ground - are real low.
You need a well timed thermal or dust devil to really screw you up.
The chances of a:
- well constructed bridle wrapping are very low
- secondary weak link holding are extremely low
So yeah, you probably have a much better chance of being killed pulling out of your driveway with you seat belt buckled and your air bags primed than you do of having all the necessary elements lining up wrong on the tow.
But right now everything on the starboard half of your secondary bridle is not only wasted real estate - it's wrap potential, working against you. Have releases on both sides. Barrel releases are cheap, don't weigh much more than the bridle itself, and give your other hand a target to grab for.
A primary / two point bridle connects at two widely separated points so it must be long enough to wrap at the tow ring. The shorter you make it the more you amplify the load going to your primary release (and shoulders). And the longer you make it the more of a pain it is to stow - and if you start getting ridiculous you stop getting any appreciable load reduction. I chose ten feet as a somewhat arbitrary sweet spot standard.
The secondary / one point bridle/release assembly connects to your body at two narrowly separated points which happen to be about the same ones that your arms do.
So regardless of how screwed up things get on tow if the distance between a release and your shoulder tow loop is a bit less than the length of your arm it's impossible for the release to get out of range.
And since the tow loops are so close together an assembly of virtually any appreciable length is going to result in an apex angle so acute that there's no force amplification worth mentioning - i.e., when you're in one point mode a release is only feeling half the towline tension.
So extend your releases out - EQUALLY - enough to give an acute enough apex angle so's your shoulder straps don't get pulled together and make the bridle itself so short that it's physically incapable of tying itself to the bottom eye of your primary bridle or the tow ring.
Tow loop to Bridle Link (either side) - about 15 inches.
Bridle Link itself - about 9 inches.
Is there less of a chance than with conventional spectra bridles? If so, how do you achieve this?
You know how to splice hollow braid Spectra, right? Take an end, make an opening, and shove the end in. Flight parks just make eye splices at both ends so, relative to the rest of the bridle, the ends are stiff and heavy - which is bad.
If you start off with a lot of excess material you can feed the ends in beyond the halfway point so there's a good length of overlap in the middle. In the middle you've got triple thickness and smooth double all the way out to the ends. Pretty nice. You've gotta secure the overlap with light stitching or you get some nasty bunching during recoil but that's no big deal - these things are pretty easy to punch out.
And you could do a secondary weak link something like the last couple of photos in:
So let's say my primary bridle wraps, the weak link on my secondary release blows, and then the secondary bridle wraps. Is there any chance the weak link on my other shoulder wouldn't immediately break? If it didn't, I'd be stuck to the line without a release (although I could of course fly with another shoulder release if that's an issue).
From your videos it appeared to me that you had a weak link on your right shoulder but the Bailey - on the left - was connected directly to your secondary bridle. If there are weak links on both ends of the bridle you're good - aside from the fact that you're using a Bailey. If the weak links are the same and one blows and the bridle wraps there's no way in hell the other one's gonna survive - instant double loading PLUS a jolt.
My statement wasn't written so much in regards to the FAA letter...
I don't recall ever having said people absolutely shouldn't be truck towing with current equipment and I've never had any interest in shutting it down. The FAA isn't involved in any towing but aero and I most assuredly don't want them to be.
But the FAA HAS been involved in aerotowing since 1984 and, given that, I'd have liked to have seen some good existing rules enforced. The fuckin' Bailey release had no business ever getting into the air and I don't ever wanna be flying behind a Dragonfly whose weak link is lighter than mine. There are enough ways to get killed in hang gliding without adding to the list me suddenly getting left with 250 feet of Spectra draped over my basetube and trailing over a barbed wire fence.
Yeah, I can probably deal with it but I shouldn't have to. And neither should you, my nephew, Jeremiah Thompson, or anybody else. I don't really care all that much if the Dragonfly itself cracks apart and falls out of the sky - as long as it takes its rope with it.
And these bastards operating these flight parks have been running USHGA and answering to NOBODY every second of the decades of their existences.
Truck towing...
For the past five years that Woiwode crash has been scaring the crap out of me. Mindset... Somebody I knew real well and, in pilot terms, always considered myself to be an insignificant insect alongside of. He goes truck towing in strong thermal conditions doing pretty much everything right, gets hit with a line problem and thermal at the same time, reacts fairly quickly, and gets destroyed.
And then I read Bill's post. And then I reread the report. And then I find this lunatic discussion from the Birren cult. And suddenly EVERYTHING's changed.
He wasn't doing everything right - he was totally clueless. He didn't get hit with two problems - line jam, thermal - at once and lose some response edge because of his equipment. He deliberately flew himself to the edge of lockout position and had a minor problem which - if he had been doing his job right - wouldn't have even been a problem. There was no thermal - he set himself up, had a winch problem, and got accelerated into a devastating low level lockout.
And then he immediately comes on the wire talking about how dangerous truck towing is.
Huge paradigm shift for yours truly.
There was a similar phenomenon going on when Bill Bennett and Mike Del Signore were killed - 1996/07/25 - in a tandem aerotow crash southeast of Cleveland.
Lotsa towing-is-dangerous bullshit. Everybody was all "If it can happen to a couple of skygods like them what are my chances?" Whole bunch of crap about weak links and getting off before the first sign of trouble.
They stalled. The tug got too high, they were heavy, they pushed out to get up with the tug, the tug didn't know how to help them out - and they stalled. Big freakin' mystery. Took me over ten years to lose enough of the first-sign-of-trouble programming to figure that one out.
So right now I don't have a great example of anyone otherwise doing things right seriously messed up by a truck tow...
Hell, right now I don't even have anything good in the way of a near miss. So OK, I might make a few truck tows with my existing equipment 'cause you're getting blasted into the air so fast and high that there just isn't much that can happen to you - as long as you STAY on tow.
But this new understanding of John's incident severely diminishes the incentive to develop equipment that doesn't scare people. And everybody with half a brain or better is scared of current equipment.
Tad Eareckson wrote:Yeah, but our swept wing IS a giant rudder...
I'd disagree and say that our wing sweep acts more like a vertical stabilizer. The rudder is a control surface that gives the pilot yaw control (which we don't have and why we're considered two-axis instead of three). The vertical stabilizer isn't enough to prevent adverse yaw. But yeah, this isn't my area either.
Tad Eareckson wrote:So extend your releases out...
Light bulb moment. So the complete assembly isn't any shorter than what I'm using, but since the releases are further out, the bridle itself is very short.
What's all that jazz between the harness loop and the release? Looks a lot more complicated than a simple rope.
Tad Eareckson wrote:From your videos it appeared to me that you had a weak link on your right shoulder but the Bailey - on the left - was connected directly to your secondary bridle.
Correct...I was speaking hypothetically.
Tad Eareckson wrote:I don't recall ever having said people absolutely shouldn't be truck towing with current equipment and I've never had any interest in shutting it down.
Zack C wrote:Since we're all using releases that require taking a hand off the bar, I suppose none of us should be flying.
I think that's a SUPER idea.
You didn't explicitly say you were interested in shutting it down, but you did say that if you did things would change, which to me implied an interest.
Tad Eareckson wrote:If I seized control of this government tomorrow, stationed my jackbooted thugs at all the airports, and outlawed all towing that required a hand to come off, I ONE HUNDRED PERCENT GUARANTEE YOU that every platform operation in the country would have buttons velcroed to their fingers by Christmas.
Anyway, just wanted to make sure what I was referring to was clear.
I got my new Lookout release in. I thought you'd find some of the included documentation interesting:
The new GT aerotow release, new as of July 11th 2009, is designed to be used with a V bridle and a 130-pound green stripe Dacron tournament fishing line weak link. At this time it is not recommended to use this release with a higher value weak link.
Guess I'm screwed. How about their tandems?
While using, note if your release requires more pull-pressures to actuate than past releases under similar conditions or if the release pull-pressures are increasing. If the release pull-pressures required to release are increasing, your release will need to be inspected. Basically, if you notice a trend of increasing release pull-pressures under similar load conditions then your release needs to be inspected.
Guess my problem is more common than I realized (enough that they need to say the same thing multiple times).
This release is a new design and had been tested to 388 pounds ultimate load connected directly to the release where the release functioned properly. With over a hundred high load releases the new release performed, as it should. With a 220 pound load at the release the release required about 16 pounds of pull to actuate the release.
Sounds like they did do some testing beyond what you did, unless they're quoting your results.
The weak link is used to protect the equipment by breaking at a set value. We recommend the green stripe 130-pound test tournament fishing line. Our tests have shown that when tied properly this line breaks consistently at 130 lbs. With a "V" bridle angled at 60 degrees or less this will give you a breaking strength of 260 lbs at the tow line.
Good to know they don't profess that a loop of 130 lb line breaks at 260 lbs. They also say that the weak link is to protect the equipment, but they still seem to have the lighter-is-better mentality (maybe by 'equipment' they mean 'releases').
Our tests utilize a double overhand knot after the weak link line is wrapped a minimum of three times around the bridle. Pull one of the wraps free and two from that line eliminating the knot from the weak link circle.
I guess by 'double overhand' they mean fisherman's. Their described method is how I was taught to tie them and how I did until I went to Wallaby and they fussed at me for not using a lark's head. I'm just mentioning this because I'm wondering if Lookout found their method to be better.
The primary release may fail at any time; this is why a secondary release must be used on all tows. Remember, you were trained to tug your primary only once before going straight to the secondary!
If properly used, there is a minimum of three ways to release from the towline. Do not depend on any of these ways by themselves and fly with a back up. The first release is the primary release which under certain situations may fail, second, is the secondary release that works most of the time, if all is set up correctly, and third, the weak link which will break under the right load. You should also fly with a hook knife that will allow you to cut the line if need be.
So even though they call it a secondary release, they mean 'backup release'. Because they admit their primary releases are unreliable. But their secondary releases are unreliable too. Fortunately, your weak link appears to be a tertiary release...I guess you activate it by performing a wingover on tow. Speaking of weak links, they only mention having one at the primary release and say nothing of bridle wraps, and their pictures show no weak link on either end of the secondary bridle (they set me up that way and I flew that way until I went to Wallaby and they fussed at me for that too). But even if everything else fails, there's always the readily accessible hook knife.
If you start oscillating or get into trouble of any sort, Release!!...If you are outside the cone of safety and unable to immediately correct your position - release immediately. If you are uncomfortable - release immediately.
How I and everyone I know was taught to think.
...if released [unexpectedly] realize that the first thing to do is keep your aircraft flying - this usually requires you to get your nose down enough to avoid a stalled angle of incidence.
This statement makes the above statement a bit ironic.
Practice using your secondary release and be able to immediately go to the secondary release while maintaining control of the glider.
So apparently it is possible to let go of the bar with one hand and still maintain control of the glider. Guess I need more practice.
I'd disagree and say that our wing sweep acts more like a vertical stabilizer.
I stand corrected and enlightened and am now more inclined to believe that we are seeing adverse yaw in the video. Cool.
I always wanted to believe that we could achieve some measure of yaw control by torqueing our basetubes but I've skimmed some of Steve Seibel's dissertations and I think I recall him saying it doesn't happen. And he does his homework. I'd really like to get him into these conversations sometime. He has a LOT of stuff right but not everything. (Launched without his leg loops about ten months ago. The gene pool can't afford shit like that.)
Light bulb moment.
Excellent. Now on to the rest of the world.
What's all that jazz between the harness loop and the release?
Short answer...
It's not important. Ignore it.
Long answer...
- The Barrel Release I make is somewhat labor intensive - mainly 'cause I'm real anal I build it to precise standards and minimal measurements. I want it short. (That photo doesn't represent what I'm doing now but it's close enough.) I want enough Barrel travel to safely clear the Pin but not much excess (wasted) play. It comes out as a clone unit that can be incorporated into anybody's one point / secondary assembly.
- Aft of the Barrel there's a little piece of vinyl tubing which serves as a Stop. It limits the travel of the Barrel to a bit over what's needed and prevents material to the aft from getting chewed up by an overenthusiastic puller. Its aft movement is limited by an Overhand Knot tied in a little length of 205 leechline the fore end of which is stitched in place.
- I want to:
-- extend the Barrel Releases out a ways so that I have an acute apex angle and reduce the forces on the releases and pulling your shoulder straps together
-- keep the Secondary / One Point Bridle itself - which is also the weak link - hence Bridle Link - as short as possible so it's incapable of wrapping following release
- And I want it perfectly centered for efficiency of design and 'cause it would drive me nuts if it weren't.
- So to address Issues 3 through 5 I have adjustable extensions - Adjusters - between the aft end of the Barrel Releases and the Snap Shackles on the tow loops. The Adjusters are Lark's Headed onto the Snap Shackles and tied onto the eyes of the Barrel Releases with a Becket Bend - which is pretty much the same as a Sheet Bend - which works on the same principle as a Bowline.
- And there's some tubing around the end of the Adjusters forming the Becket Bend to hold it flush and make it look pretty.
But once set everything between the Barrel and the tow loop is inert. So ignore it.
Correct...I was speaking hypothetically.
OK. But it's not too much of a stretch to get that ACTUAL configuration to kill you. So for stopgap have doubled loops of 130 pound Greenspot at your primary and secondary releases and at your right shoulder. In the worst case scenario that you're never gonna encounter you'd hafta hit the Bailey with about a 35 pound pull. You can do that if you're anticipating it (and don't have a lot of other issues going on at the time).
You didn't explicitly say you were interested in shutting it down, but you did say that if you did things would change, which to me implied an interest.
Odds are I'd have a limited number of jackbooted thugs at my disposal so I'd have to prioritize things.
- The fix for platform towing is either sloppy - lotsa junk in the airflow - or complex, difficult, and expensive.
- Ignoring (or even considering) the release issue, platform launches are safe - in theory and practice - and brain dead easy. The glider is bolted into place and trim until the driver gives the green. You've got virtually unlimited power and speed, and the glider gets blasted straight up.
- You're on a good tension controlled payout system. It's hard to lock out and even a crappy release can't get overloaded.
- At least down in your neck of the woods you seem to be using proper weak links.
- Relatively speaking, you aren't having any problems.
Aerotowing is pretty much the precise opposite of platform towing. And the fixes are all - INFURIATINGLY - cleaner, easier, simpler, cheaper than the crap that's causing the problems. I'd have my jackbooted thugs summarily execute a few dozen war criminals, start the mass sterilization program, and get the fixes in place - a day and a half and things would start looking up for the planet.
But since last writing I've reviewed a couple of interesting truck tow incidents. Homework assignment...
This was a very short flight at BlueSky Flight Park. The right wing lifted slightly just before release, I corrected easily enough only to have it lifted again to the point I just had to release.
This is the first time I have had a turn that I couldn't quickly correct for in many years (at least 17).
Talking with Steve after the flight, I assumed I had crossed controlled. The video has been very helpful. Case in point, which hand to take off the bar while correcting aggressively, and I should pull in to correct a turn under tow too. I'm thinking that subconsciously, I knew which hand had less pressure, therefore which hand to use.
The weak link should break with a lockout. I wasn't locked out, but getting close. Had I been locked out, and the release not worked, I would have been screwed. So, pin off early to prevent it from going that far. Other than that, pray you have a good tow operator.
The release we use is called a 3 ring circus, very simple and very reliable.
This is a seventeen year tow pilot who starts locking out low on a platform launch.
He's appropriately scared about the issue of taking a hand off the basetube in an incipient lockout. It shouldn't be a matter of WHICH hand he wants to remove and HOW MUCH control he THINKS he's gonna be able to sacrifice.
This is a seventeen year tow pilot at Steve Instructor-Of-The-Year Wendt's operation who expects the weak link to blow:
- in a lockout
- in a lockout on a payout winch
Telling people to pin off early is even more useless than telling people to remember to hook in before launch. Nobody deliberately launches unhooked or rides into a lockout - it's a matter of having the procedures and hardware, respectively, to maximize success. And while it's never desirable to launched unhooked it's way more likely be safer to stay on tow to deal with problems than blow.
I thought you'd find some of the included documentation interesting...
INTERESTING? THANK YOU SANTA CLAUS!!! Photocopy the instruction sheet and get the original into safety deposit box - IMMEDIATELY!
(Seriously, can you scan that documentation and wire me a copy?)
Matt's trying to cover the hell out of his ass but in the process is virtually screaming that he's operating in violation of the USHGA aerotowing SOPs and thus FAA Exemption 4144.
Our SOPs allow a weak link up to two Gs and the release is required to be able to handle twice weak link.
The new GT aerotow release, new as of July 11th 2009, is designed to be used with a V bridle and a 130-pound green stripe Dacron tournament fishing line weak link. At this time it is not recommended to use this release with a higher value weak link.
Translation: Use it only with a weak link that has maimed and killed people or the release itself will maim or kill you.
They:
- dispense 200 pound Greenspot - in addition to 130 - at the flight line
- recommend a double loop of 130 for "heavier" gliders - such as yours (260 pounds) - that can't even follow the tug into a turn on a single.
And you have that lovely little video illustrating how useless and potentially lethal it is for an average weight solo.
And absolutely no reference to Gs.
Note the similarity. See the weak link in the photos?
Look familiar?
The SteevRelease was designed to be an integral part of a three point Aero tow bridle and was not designed to be used in a two point (Pro Tow) or as a single point tow release.
Translation: I haven't bench tested it and am not even sure it'll handle a loop of 130 (whatever the hell that holds to). But for the love of God don't load it up ten pounds over that.
How about their tandems?
No problem. They don't even use weak links on their tandems. That could get real interesting 'cause they are - or were anyway - using Quest releases on them. And Quest figured out how to kill over sixty percent of the spinnaker shackle's already anemic mechanical advantage.
This is all win-win.
If they don't use it on the tandems... If:
- this is such a great release - why not?
- both hands on the basetube is such a big safety deal - how come they're so willing to endanger their tourists and students with a lever on the downtube?
- this new release can't handle tandem how come they're using one the testimonial they've got up on their website (see below) almost categorically states handles the load even worse?
If they do use it on the tandems how come they're using a release that they don't trust over a single loop of 130 on a glider that a single loop of 130 wouldn't hold long enough to allow it to roll?
Basically, if you notice a trend of increasing release pull-pressures under similar load conditions then your release needs to be inspected.
I really get tired of people who don't know the meaning of the word "pressure" - especially people who are putting other people in the air.
Inspected for WHAT?
Can you inspect it yourself or do you hafta mail it back to the crack Lookout GT Release Inspection Panel - and hope they're not too backlogged.
What do you fly in the meantime? Another Lookout GT Release that can't reliably function with a loop of 130? Why aren't they sold in pairs? Or do you just tow one point on their Baileys and lose the abilities to release with both hands on the basetube, release under load, and stuff the bar?
Or can you just inspect it and put it back in the air without actually having to do anything first?
Guess my problem is more common than I realized (enough that they need to say the same thing multiple times).
Thrice in three consecutive sentences. Just in case the warning has faded from your memory a bit... If you notice a trend of increasing release pull-pressures under similar load conditions then your release needs to be inspected. Unless, of course, you notice this trend under higher than normal load conditions when your glider's sideways just after launch - then getting it inspected won't make any difference.
I despise cable.
There's a good guy from the DC area named Tim Hinkel who's machinist who put a lot of expertise into designing a rather nice slap-on cable actuated release. I told him up front that I hated cable and slap-on but I thought there was a place for something like that and I'd do whatever I could to help him.
He incorporated a couple of my suggestions and punched out a prototype:
that I took home for some serious testing. It would've worked well enough for normal use but it was so problematic when you started going worst case scenario that I eventually concluded it was just the wrong way to do a critical job and I was wasting my time putting lipstick on an attractive and well mannered pig. It was just way cleaner, easier, simpler, cheaper to do the job right - like I already had.
Sounds like they did do some testing beyond what you did, unless they're quoting your results.
I'll tell you EXACTLY what Matt did.
- He put it in the air completely untested. On the plus side he let Marc Fink use one so that could've worked to the advantage of hang gliding but - alas - didn't.
- He sent a copy off to Wills Wing to get them to do his job for him - but they didn't.
- He conned me into coming down to Lookout on what I belatedly realized was the absolutely absurd premise that he had an interest in revising the USHGA standards to something safe and sane and got me and my rig doing his job for him testing his release, weak links, and tow rings.
- 388 pounds is the top of the lower range of my rig. I cranked it up and blew it with a surprisingly easy pull. (I couldn't remember if I had redlined it so I played it safe and said 375 earlier.)
- Long before my return to Maryland I realized I wanted absolutely nothing more to do with Matt - ever - and had no more interest in testing anything of his.
- Afterwards they undoubtedly hung some 220 pound instructor from the release and found that some 16 pound chunk of metal from the shop hung from the cable loop would drop him. (Before I built my rig and started doing things right I'd put my 220 pound (same weight) ass in a sling and drop it on a stack of sofa cushions downstairs. (Don't ever do that - it's a lot more dangerous than you'd think.)
The way I test releases is to load them up on the rig and run a line from the actuator through a pulley to a bucket. You slowly pour water into the bucket until the release blows and then weigh it.
You compare the load to the bucket and you get an actuation ratio.
I do this over a range of loads but have found that all releases stay pretty linear/predictable.
The weak link is used to protect the equipment by breaking at a set value. We recommend the green stripe 130-pound test tournament fishing line.
- Equipment that needs the protection afforded by that weak link couldn't survive being carried from the setup area and loaded onto a dolly.
- WHY do you assholes recommend that weak link? What's the data upon which you're basing that recommendation? What's your "thinking"?
- Who is "we" and what are "our" qualifications?
- Do "we" recommend this same weak link for 200 and 350 pound gliders?
Our tests have shown that when tied properly this line breaks consistently at 130 lbs.
However Zack's flight test on 2010/11/27 showed otherwise.
With a "V" bridle angled at 60 degrees or less this will give you a breaking strength of 260 lbs at the tow line.
- Unless you've stayed in school beyond fourth grade. Then it gives you a breaking strength of 226 pounds at the towline at sixty degrees and 251 at thirty. And you never make it all the way back up to 260 no matter how long you make the bridle.
- Sixty degrees. That's the number I set for my standard for my USHGA revisions and all my calculations and documentation. A hundred bucks says they ripped it off from me.
Good to know they don't profess that a loop of 130 lb line breaks at 260 lbs.
- Matt didn't really have a clue what his weak links were doing until I got down there.
I know I've said this before, but...
- As far as I'm concerned and regardless of what a loop of new 130 tests to on the ground - They regularly fail in the air at 125 pounds of tow tension, therefore they must be considered 72 pound loops.
- And, yeah, you've had used ones tested back on the ground to pretty close to what a new one does so that just means they've got zilch in the way of predictability.
They also say that the weak link is to protect the equipment, but they still seem to have the lighter-is-better mentality...
Until they wanna make money on their tandem rides. Then they don't even want the possibility of even a two G weak link interrupting the revenue flow.
...(maybe by 'equipment' they mean 'releases').
What Matt's really using the weak link to protect is himself.
For thirty years hang gliding has been conditioning people to think of weak link failures straight and level every fourth tow as a normal and necessary part of the landscape.
And for twenty years the flight parks have been making 130 pound Greenspot the mandatory standard for all solo aerotows and have made it unthinkable - as well as forbidden - to even consider anything else.
So now he can sell whatever crap he wants in the way of releases without having to worry the slightest bit about liability.
I have to use a weak link which - at best - leaves me shy of 0.8 Gs and almost certainly will kill me in the early stage of a Pagen scenario.
If I use something stronger to allow me to survive rocket mode by staying on it's not his fault if the release jams when I try to blow tow at 1.0 Gs as I'm entering lockout mode 'cause it says right there in the owner's manual:
...it is not recommended to use this release with a higher value weak link.
And if it jams at half a G using the 130 he's still good 'cause he's cautioned me that the pull-pressures increase over time.
Pull one of the wraps free and two from that line eliminating the knot from the weak link circle.
I think you mean "tow". (That's a typo I make all the time.)
I guess by 'double overhand' they mean fisherman's. Their described method is how I was taught to tie them and how I did until I went to Wallaby and they fussed at me for not using a lark's head. I'm just mentioning this because I'm wondering if Lookout found their method to be better.
C'mon Zack - they haven't FOUND anything about their "method". All this crap is based on:
- Donnell's:
-- ASSUMPTION that a one G max weak link would prevent anything bad from happening to a surface towed glider
-- PRONOUNCEMENT that an aerotow weak link must be lighter that a surface tow weak link - static or payout
- Wallaby/Quest's ASSUMPTION that:
-- 130 pound Greenspot tied with a Fisherman's Knot "isolated" in the middle of the Double Lark's Head by which it was installed on the bridle end would hold to 260 pounds.
-- the bridle apex angle had no bearing on the load to which the weak link was subjected.
-- a weak link on one end of a bridle limited the tension to exactly what it would if you put it on the end of the towline.
-- all gliders flew at 260 pounds. (You lucked out on that one.)
- Dennis Pagen's ASSUMPTION that all the assholes running these shows had a fucking clue what they were doing.
- All the rest of the assholes assuming that the other assholes knew what they were talking about. (And, yeah, we're both recovering assholes.)
You think anybody ever bothered to actually TEST anything? Let alone do any comparative testing?
When you're talking knots and placement you're talking about something that MAYBE makes five pounds difference in a weak link that blows at anything over a seventy pound range and should be about twice the top end of that range to begin with. Talking about knots in a loop of 130 is like discussing which type of spoon is best for chopping down an oak - tea or soup.
IF I had to use a loop of something as a weak link I'd use a Fisherman's Knot 'cause that's the best knot to form the loop and a Double Lark's Head 'cause that's the best knot to install it and keep it on the bridle. And I'd center the Fisherman's Knot 'cause that would make it neat and pretty. But none of that would have enough bearing on the break point to be worth mentioning.
Don't understand the Fisherman's Knot versus Lark's Head thing. You need the former - or something similar - to form the loop and the latter to install it.
The primary release may fail at any time; this is why a secondary release must be used on all tows.
Fuck that. In a situation in which it matters you've got one second - if that - to get the job done.
"The hydraulic braking system may fail at any time; this is why a parking brake is mandatory equipment on all cars."
Remember, you were trained to tug your primary only once before going straight to the secondary!
Aw, c'mon Matt. It's a Lookout release. Give it four shots before you go to the secondary and risk tucking the glider.
The first release is the primary release which under certain situations...
At altitude, smooth air, normal tension, straight and level.
...may...
Does.
...fail, second, is the secondary release that works most of the time...
Great!
...if all is set up correctly...
Which, the way you assholes set up Zack, with a bent pin and no weak link limitation, it isn't.
...and third, the weak link which will break under the right load.
SUPER!
What's the right load?
Is it possible to slam into the runway at only half the right load?
What happens if your only weak link is on the end of the bridle that's just tied itself to the tow ring?
You should also fly with a hook knife that will allow you to cut the line if need be.
Yeah. The hook knife. Let's not forget about the hook knife.
- This release is the greatest thing since sliced bread because it allows you to blow tow in a low level emergency with both hands on the basetube without interruption of control.
- And the fact that "the primary release may fail at any time" is no big deal because you've got a backup and there's no possibility of the bridle wrapping, leaving you with no way to release or even hook knife yourself free, with the full tow tension going to a point on your keel a foot fore of your hang point, and tucking you back into the runway.
- And whereas two hands on the basetube and fractions of a second were critical BEFORE the new Lookout GT (Gone Tomorrow?) Aerotow Release didn't...
-- One hand is now plenty enough to get you by.
-- You can use one of your two time-outs to stop the clock and start working the Bailey or hook knife - whichever is easier to get to and/or make function.
-- You can request an extra 250 feet from the flight park manager to roll the glider, blow the weak link, recover from the stall, and land.
So even though they call it a secondary release, they mean 'backup release'. Because they admit their primary releases are unreliable. But their secondary releases are unreliable too. Fortunately, your weak link appears to be a tertiary release...I guess you activate it by performing a wingover on tow.
Here's your new bike Tommy. The brakes don't work very well - especially over fifteen miles per hour in a panic stop. So if they fail in an emergency just take the pump and shove it in the front spokes. Lean back as much as you can to minimize the chance you'll get flipped over the handlebars. If the pump disintegrates before you stop there's a grappling hook tied to your seat post. Throw that back - it'll eventually catch on something. And if you see any broken glass glass on the road, try to run over it - that should blow your tires and help slow you down.
What a scumbag.
Speaking of weak links, they only mention having one at the primary release and say nothing of bridle wraps, and their pictures show no weak link on either end of the secondary bridle (they set me up that way and I flew that way until I went to Wallaby and they fussed at me for that too).
Hang Gliding - 1997/02
Tad Eareckson
To further address the danger of a primary release failure (bridle wrap), a secondary weak link, of strength somewhere between significantly stronger than and double that of the primary, should be installed at the other end of the primary bridle.
Try to find a secondary weak link anywhere in Towing Aloft, 1998/01.
While we're on this topic...at Wallaby in April the launch crew put a second weak link in my system between the bridle and the Bailey. I fly with a two point, Wallaby-style release, with a single Bailey secondary. As I recall, here's the scenario they had in mind:
Pilot releases with primary, bridle catches on the tow line or release mechanism. If pilot becomes extremely out of position, the additional weak link would probably break prior to pilot finding and pulling Bailey.
Does anyone else use two weak links, one on each release point?
If I say something that makes obvious sense it gets totally ignored for all eternity. If a flight park says the same thing eight years later people start discussing it. That post was from the local club and Ridgely had been operating for six and a quarter years at that point.
But fear not, bridle wraps don't happen at Lookout.
Matt Taber - 2009/05/11 22:48:48 UTC
In all of my experience as a pilot -- tandem pilot and tug pilot I have not seen, heard about or experienced this. Is it really an issue or a perceived issue?
Towing Aloft - 1998/01
I witnessed a tug pilot descend low over trees. His towline hit the trees and caught. His weak link broke but the bridle whipped around the towline and held it fast. The pilot was saved by the fact that the towline broke!
Once again history has shown us that this thread-through system can hook up and the hang glider remains being towed by the keel only, with the bridle well out of reach of even a hook knife. I know of just one pilot to survive this type of hook-up, took him some twelve months to walk again though.
Right Matt. 'Cause YOU haven't experienced, seen, or heard or read about and can't conceive of the possibility of a bridle failing to clear a tow ring you should instruct, sell equipment, and write procedures as if this were a physical impossibility.
If you start oscillating or get into trouble of any sort, Release!!
Yeah, don't worry about what point you're at in the oscillation cycle - just release. And if you're the tug driver wait until the glider's at an extreme before you dump it. Reconstructive surgeons are doing marvelous things with titanium nowadays.
How I and everyone I know was taught to think.
How we were all taught NOT to think.
This statement makes the above statement a bit ironic.
This statement assumes the glider will still be flying. This statement assumes you'll have enough air below you to GET the glider flying again.
Matt Taber - 2009/05/11 22:48:48 UTC
We do know that if you keep your energy and do not push out while low and give your energy away that you can safely release at anytime without issue.
Dennis Pagen - 2005/01
I pulled in all the way, but could see that I wasn't going to come down unless something changed. I hung on and resisted the tendency to roll to the side with as strong a roll input as I could, given that the bar was at my knees.
Analyzing my incident made me realize that had I released earlier I probably would have hit the ground at high speed at a steep angle. The result may have been similar to that of the pilot in Germany.
Imagine if you will, just coming off the cart and center punching a thermal which takes you instantly straight up while the tug is still on the ground. Know what happens? VERY high towline forces and an over-the-top lockout. You'll have both hands on the basetube pulling it well past your knees but the glider doesn't come down...
Yeah Matt, there's all kinds of crap you can get away with when the shit ISN'T hitting the fan.
So apparently it is possible to let go of the bar with one hand and still maintain control of the glider. Guess I need more practice.
Dennis Pagen - 2005/01
By the time we gained about sixty feet I could no longer hold the glider centered - I was probably at a twenty degree bank - so I quickly released before the lockout to the side progressed. The glider instantly whipped to the side in a wingover maneuver.
...and still the weaklink doesn't break (.8 G). So you pull whatever release you have but the one hand still on the basetube isn't enough to hold the nose down and you pop up and over into an unplanned semi-loop. Been there, done that... at maybe 200 feet agl.
Yeah Zack, you suck. Get serious and practice more. Physics is never an obstacle to the True Believers.
And from Matt's website...
Aerotow Primary Release
14-9004
$139.95
The best release in the industry.
The most environmentally conscientious practices in the mountaintop removal coal mining business.
This Aerotow Primary Release represents the state-of-the-art in releases. Made at LMFP, this release features the Rope-Loop type release mechanism, a better alternative to the lever release...
Like the one we use for rides and training on our tandem gliders.
...as you don't have to let go of the basetube to release.
As you do on the already highly compromised one point aerotow assembly we sell.
We are very excited about our new barrel release mechanism. It has exceeded all of our expectations and has passed rigorous testing.
But don't subject it to more than 130 pounds and expect it to degrade without warning for reasons we won't specify in the owner's manual.
Yeah Matt, your expectations have always sucked. And, thanks to people like you, everyone else's expectations of tow equipment suck too.
A recent testimonial from a long time aerotow pilot...
Hi Matt, Just a quick note to let you know how much I like your new Primary Aerotow release.
Even though your Secondary is the same crap it always was.
Living in the flat lands of the mid-west, I've been towing hang gliders, using ground-based towing systems, since 1983 and, using aerotowing systems, since 1992. Over the years, I've used just about every kind of bridle and release system I saw or even heard about.
Which obviously includes the Lookout spinnaker shackle based two point and the brake lever junk from Florida.
Some were commercially made and some were homemade. They all worked pretty well as long as long as I was in, more or less, straight and level flight and there was no extraordinary tow force being exerted on the release.
Extraordinary, of course, being defined as anything approaching triple digits.
But, While rolling on the launch cart or just after leaving the cart and blundering into a thermal or otherwise getting out shape and entering into an incipient lock-out...
À la the dead German pilot, Dennis, and Peter - indicating this shit happens a lot more than we get to hear about.
...the problems with all of my previous releases reared their ugly heads. Either I was so out of shape that I didn't want to let go of my base tube in order to activate my release...
Whoa!!! Who coulda seen THAT coming?
The United States Hang Gliding and Paragliding Association, Inc.
Standard Operating Procedure
12. Rating System
02. Pilot Proficiency System
10. Hang Gliding Aerotow Ratings
-B. Aero Vehicle Requirements
06. A release must be placed at the hang glider end of the tow line within easy reach of the pilot.
So what you're saying is that there's really no such thing as "within easy reach" when the shit hits the fan? That "within easy reach" is basically an old and deadly lie?
...or the tow pressure...
TENSION.
...would quickly build up to the point where the release wouldn't operate.
Yeah. It would just rocket up until the release was feeling maybe eighty to a hundred pounds. Couldn't have been much more than that 'cause your weak link didn't blow.
And, while we're on the subject, notice that your weak link wasn't blowing in time to keep you out of trouble the way Matt - like all these other assholes - is telling you it will in his literature.
This release shall be operational with zero tow line force up to twice the rated breaking strength of the weak link.
Meaning that not a single one of the sonsabitches who sold or themselves used this junk made the slightest pretense of complying with these regulations - even with this dangerously understrength weak link - one barely able to sustain you on tow - providing the ticket to sail on through this obscenely generous loophole.
Since these situations occasionally do happen...
And occasionally do kill people.
...until this summer, I was still searching for a better release.
Did you try googling "aerotow release" and getting in touch with me?
One which I could operate without taking my hand off of the base tube AND one which would still operate using moderate release force with the tow pressure...
TENSION.
...approaching the breaking strength of my weak link.
WHICH WAS WHAT??? As if we didn't know...
I think that, for now at least, my search is over. Not only has your new release been elegantly designed, it also works as advertised!
Which should - but obviously doesn't - scare the crap out of you.
Thanks for making this improved design available to us tow heads.
Ralph Sickinger - 2000/08/26 22:18:20 UTC
After towing to altitude, Sunny waved me off; I pulled on the release (hard), but nothing happened! After the second failed attempt to release, I thought about releasing from the secondary, but before I could move my hand the tug stalled and started to fall...
Brian Vant-Hull - 2000/08/28 22:49:13 UTC
I purchased my release (the one Ralph used) at Lookout Mountain over a year ago, but never had any problems until the Ridgely Fly-In, where the same thing happened. I pulled three or four times on the release, then finally went to the secondary, by which time I was high above the tug and Sunny was frantically waving me off.
I've found it to fail this way once more since then, then on Ralph's flight, for about one time in ten.
Yeah Matt! Thanks! Thanks for spending a decade and a half or so flooding the market with expensive, noncompliant, dangerous junk and convincing people to buy more expensive junk with enough serious warnings and disclaimers on it to make a tobacco company CEO wet his pants. So are you gonna let all the purchasers of your old defective hardware trade it in for copies of your new improved defective hardware?
