Weak links

[Tad Eareckson]

Jump to next post:
http://www.kitestrings.org/post9479.html#p9479

http://ozreport.com/forum/viewtopic.php?t=48131
We can and should have more directional control

Steve Corbin - 2016/06/05 21:13:50 UTC

I get a lot of flack...

Try spelling it correctly. Then maybe you'll get less of it.

...from saying this stuff, but I'm a believer...

Oh good. Just what hang gliding needs - more believers.

...and have thick skin...

And skull.

...so here goes:

I have witnessed many incidents and accidents where if the "pilot" had had adequate roll control then it wouldn't have happened.

- How many incidents and accidents have you witnessed in which the pilot had adequate roll control with one hand on the control bar?

- What's your take on the adequacy of roll control when "pilot" is flying with...

http://ozreport.com/forum/viewtopic.php?t=27086
Steve Pearson on landings

Steve Pearson - 2012/03/28 23:26:05 UTC

I can't control the glider in strong air with my hands at shoulder or ear height and I'd rather land on my belly with my hands on the basetube than get turned downwind.

...his hands on the control tubes at shoulder or ear height?

We've obviously got roll control to SQUANDER - the more critical, dangerous the phase of flight the more we squander it. Somebody show me a video of somebody boating around two thousand feet over in glass ridge lift with both hands at shoulder or ear height on the control tubes or one hand on the basetube (VG adjustments...

13-02306
http://c2.staticflickr.com/2/1698/25936289086_880146dd50_o.png


...and short rest periods...

059-155408
http://c2.staticflickr.com/8/7722/27019819284_2d5929f75a_o.png


...don't count.)

It's my firm belief that our current flex wing designs have adequate control for normal flying far from anything to hit.

It's my firm belief that our current flex wing designs have adequate control for normal flying far from anything to hit with the pilot dangling from the basetube and the empty hang strap fluttering in the breeze. Aviators tend to do just fine no matter what as long as they're far from anything to hit. The fuckin' Challenger crew members were all just fine until they were no longer far from anything to hit.

But in 40 years of flying a bunch of different gliders I've come to the conclusion that we don't have adequate control in many situations.

Name a fixed wing aircraft that DOES.

I've read too goddamned many reports of pilots dying or suffering serious injury due to this lock-out phenomenon.

How many goddamned reports of pilots dying or suffering serious injury due to this lock-out phenomenon with releases that didn't stink on ice have you read? Cite ONE.

19-04610
http://farm3.staticflickr.com/2809/13746340634_a74b33d285_o.png


And how much towing have you done, been around, discussed with anyone who knows what the fuck he's talking about?

This ridiculous state of affairs continues to be put up with by folks who should know better.

- Helps out a lot with the gene pool.
- This ridiculous state of affairs was developed and is maintained and enforced by the cartel that controls this sport.

It's 2016 and we have gobs of engineering ability...

Gobs of it. Before hang gliding really brought its collective genius to bear towline pressure was known and referred to as "tension".

...and yet we still cling to the idea that we should only allow pure weight shift control in competition, even though it is glaringly obvious that it ain't effective enough.

How I wish we did and engineered our critical control equipment to actually allow continuous pure weight shift control while effecting the dumping of lethally misaligned tow pressure.

Yeah we'll aerotow 99 times and have little or no problem, but then on our 100th a dust devil, invisible on a grass field, kicks us into a yaw roll position from which the only possible way out is to release and get back under control, but as we see in too many cases there is a window of vulnerability that we created by insisting on using an antiquated method of controlling our gliders.

Get fucked, Steve.

- One percent of our tow launches are into invisible dust devils we survive only by releasing. We could fund our tow operations five hundred percent by selling tickets to shit like that if it actually existed.

- Funny that Cessnas taking off on paved runways which don't help much with dust devil visibility don't seem to be hitting dust devils fifty feet off the deck one percent of the time.

- Crashes of gliders attributable solely to dust devils launching, landing, flying on tow or off are statistically nonexistent.

- The textbook dust devil towing disaster was Eric Aasletten, 1990/07/05, Hobbs. The assholes KNEW they had dust devil blowing across the runway, they were invisible because of the grass on the surface and the fact that they couldn't be bothered to put streamers up, and what killed him was coming OFF tow, courtesy of his Birrenator configured platform launch release, NOT staying ON. And there was zero issue with roll, yaw, lockout.

- The problem with towing is that assholes get away with flying shit equipment tens of thousands of consecutive cycles with no penalty as severe as a skinned knee and use the numbers to advertise their outstanding safety records when, in fact, one serious equipment precipitated crash in a hundred thousand cycles is a total shit record.

I WISH the penalty for flying cheap Quavis bent pin shit were one dust devil emergency situation for every hundred flights. Nuthin' like a high serious crash rate to clean out the gene pool and drive evolution.

If we're in that window when the rouge air current finds us we won't be high enough to fix things.

Gotta watch out for that rouge air. Rogue elephants...



...too.

Yeah we may save a few bux by doing it this way, but how many more accidents will there be before we get it through our thick skulls that maybe it's time to back up and regroup.

- The obvious inspiration for this thread of yours was Jeff Bohl, 2016/05/21. That was not an "ACCIDENT" by any stretch of the imagination. That was a very predictable CRASH precipitated by:
-- strong crosswind conditions
-- marginal crosswind runway
-- underpowered tug - unsafe by Jim Keen-Intellect Rooney's own definition
-- one of the hard low altitude turns which were just becoming SOP
-- pro toad bridle which illegally decertified the glider
-- illegal total shit "release" perpetrated by the meet heads

- Fuck regrouping. The goddam group is the fundamental problem. Don't reconstitute it. Destroy it.

- Yeah Steve, let's reinvent the sailplane. I'll start holding my breath now while all you great innovators get a few models into production.

Every time a pilot has to release due to the lock-out phenomena...

...it suddenly dawns on the total fucking moron that...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3391
More on Zapata and weak link

Paul Tjaden - 2008/07/22 04:32:22 UTC

I got clobbered and rolled hard right in a split second. I have never had a lockout situation happen so quickly and dramatically and had no chance to release as I have always thought I could do.

...that he actually needs TWO hands to fly the glider. 'Cause the total fucking moron is totally incapable envisioning a real world lockout situation or learning the least goddam thing from...

Bill Bryden - 2000/02

Dennis Pagen informed me several years ago about an aerotow lockout that he experienced. One moment he was correcting a bit of alignment with the tug and the next moment he was nearly upside down. He was stunned at the rapidity. I have heard similar stories from two other aerotow pilots.

...decades worth of actual incident reports.

...even when it occurs high enough to not be a significant set back, is another indictment of a policy that quit being viable several decades ago.

And Paul continued to use his moronic pro toad bridle and bent pin releases and went back to using and relying on the Standard Aerotow Weak Link as his lockout protector / emergency release.

How 'bout when sailplanes HAVE TO release? Conventional gliders and tugs have highly engineered, expensive, bulletproof systems built into their planes that they can actuate without interrupting full three axis control when things start going tits up. Is every emergency release in sailplane aerotowing an indictment of the whole system?

But until we admit we have a problem nothing will get done about it.

Write the FAA the way I did the better part of seven years ago 'cause u$hPa refused to comply even with its own SOPs. I'm probably only the second person in the history of the sport to have done anything like that and it didn't get any problems fixed - but:
- it scared the shit outta u$hPa
- I:
-- can watch all these fatalities now with a clear conscience
-- get all these really great toldyaso moments all the fuckin' time now

And this particular problem exists in hill launching also.

No shit. And it's way the fuck worse in hill launching 'cause those assholes gotta use their feet to power themselves up to speed and are upright with their hands on the control tubes as they're getting airborne. Plus the environment is usually about a hundred times nastier.

15-05409
http://farm6.staticflickr.com/5614/15725737265_b19cd24e84_o.png

23-05826
http://farm4.staticflickr.com/3941/15702014836_de575a54a2_o.png

32-10300
http://farm4.staticflickr.com/3943/15106340443_17341e17fb_o.png

Pure weight shift, without some kind of augmentation, is simply inadequate to our task at hand, and needs to be recognized as such.

Bull fucking shit. ANY well designed aircraft will have its plusses and minuses, tradeoffs. These things CAN BE operated with as fat safety margins as we elect to impose. Want better roll control authority? Launch, fly, and land them faster. We get MORE roll responsiveness than some flyers know how to handle.

In those last seconds of his life the pilot that died recently became a believer.

Bullshit. Jeff died wishing he had had a third strong hand to try to pry open that bent pin shit with which he flew because that's what everyone else flew with and it had a really long track record. Some of us have been screaming warnings about it for decades. Jeff wasn't the least bit interested.

Jeff watched THIS video:

http://www.youtube.com/watch?v=rNq1WKy0EqE


...in which at the one minute mark we see Ty Taylor having to deliver...

18-10115
http://c1.staticflickr.com/9/8281/29660706145_8aec1431f6_o.png

19-10127
http://c1.staticflickr.com/9/8407/29660704645_411aec4ae1_o.png

20-10202
http://c1.staticflickr.com/9/8002/29660703075_9ff03a21a9_o.png

21-10206
http://c1.staticflickr.com/9/8223/29660701775_d8714f050d_o.png

22-10211
http://c1.staticflickr.com/9/8414/29660700435_60e7a82e47_o.png

23-10215
http://c1.staticflickr.com/9/8168/29036020063_02116a2fdd_o.png

24-10221
http://c1.staticflickr.com/9/8536/29660697885_269cb53671_o.png

25-10223
http://c1.staticflickr.com/9/8372/29549603522_ae88a055f4_o.png


...FOUR SHARP JERKS to one of the pieces of shit that Lockout Mountain Flight Park sells to the public as aerotow releases to get it to function...

27-10225
http://c1.staticflickr.com/9/8235/29549600192_3cde241224_o.png

28-10300
http://c1.staticflickr.com/9/8176/29369898290_b0d35bbbc9_o.png

29-10304
http://c1.staticflickr.com/9/8005/29369897860_15bcc594c2_o.png

30-10328
http://c1.staticflickr.com/9/8089/29369897410_7c110e9641_o.png


...and comments:

Jeff Bohl ~ 2015/10/12

Dang the kid is a natural. That was a pleasure to watch!

He may have been a pilot in his day job but he was just another stupid dope on a rope in hang gliding.

Is that what it's going to take to convince you?

Not a millimeter's worth.

I really enjoyed the video of the sailplane under aerotow...

http://www.youtube.com/watch?v=PY-6hVRmC1U

...performing precision axial rolls under tow.

19-A10954
http://c2.staticflickr.com/8/7078/27367676330_ce004cd1b4_o.png

20-A11030
http://c2.staticflickr.com/8/7758/27007821683_a4728a9755_o.png

21-A11100
http://c2.staticflickr.com/8/7404/27007821313_41e241cd93_o.png

22-A11126
http://c2.staticflickr.com/8/7041/27007820783_0af7037075_o.png

23-A11154
http://c2.staticflickr.com/8/7720/27007820453_274db0991e_o.png

24-A11218
http://c2.staticflickr.com/8/7698/27007819973_45ae6021a8_o.png

25-A11242
http://c2.staticflickr.com/8/7534/27007819603_88cce1ff4b_o.png

26-A11306
http://c2.staticflickr.com/8/7576/27007819213_169f4f255e_o.png

27-A11326
http://c2.staticflickr.com/8/7087/27583392486_cf3bb5a16f_o.png

28-A11346
http://c2.staticflickr.com/8/7053/27583392286_98f35f25ec_o.png

29-A11434
http://c2.staticflickr.com/8/7634/27583391866_1c4b2524fb_o.png

I don't think we need anywhere near that degree of control...

Really? Maybe we shouldn't be turning hang gliders upside down without pulling negative Gs?

...but we sure as hell need more than we have.

Bullshit. We fly pro toad bridles, use easily reachable releases, and have standard aerotow weak links to blow tow in emergencies. If we sure as hell needed more control we'd be flying two point bridles, releases that didn't stink on ice, and weak links which protected our aircraft against overload.

OK flamers, come and get me, I'm holed up with plenty of firepower.

Davis is gonna delete your thread sometime before about 2016/06/08 15:00:00 UTC and you're gonna let him get away with it without protest, complaint, any effort to post the original material you should've archived and rekindle the discussion.

Steve, who only wants to be truly helpful.

Great job wanting to be truly helpful. Meanwhile, out in the real world, we've developed the stuff, put it in the air, solved the problems engineering-wise and are bashing the motherfuckers who are doing their best to keep it out of circulation into OBLIVION. Ryan Instant-Hands-Free-Release Voight is gone, Jim Keen-Intellect Rooney knows he can never again open his fuckin' mouth again on any AT issue, Davis Dead-On Straub is on the goddam ropes.

P.S. Steve...

Did ya watch the Part 2 video...

http://www.youtube.com/watch?v=8TmqFMTAQB8


...in which he RELEASES from the tug in the first couple seconds?

30-B00000
http://c2.staticflickr.com/8/7105/27583391536_2668d46807_o.png

31-B00050
http://c2.staticflickr.com/8/7658/27583391246_91c5048748_o.png

32-B00208
http://c2.staticflickr.com/8/7707/27583390836_a430a349ce_o.png

33-B00250
http://c2.staticflickr.com/8/7353/27583390456_a0b487300a_o.png

34-B00414
http://c2.staticflickr.com/8/7357/27583389986_d2198dc311_o.png


Anything there worth duplicating for hang gliding?

Jump to top:
http://www.kitestrings.org/post9473.html#p9473

[Zack C]

Real sorry we've lost Zack. I think the situation with him is that he can't continue speaking out and continue to fly and be part of a flying community.

I'm afraid the truth is far more mundane...

1. I simply got tired of the debates. My priorities have shifted and there are other things I want to spend time on. I don't even read hanggliding.org or the Oz Report anymore. Lately I've been doing more triking than hang gliding anyway...think I flew in a few too many circles. =) (I'd actually really be up for some ridge soaring for a change, but both Quintana and Packsaddle are closed now.)
2. After seeing how stubbornly the general flying population clung to the status quo, my mentality drifted away from proactively trying to effect positive change to just doing what I think is safe and explaining the reasons to anyone curious.
3. Part of the reason I participated in discussions outside Kite Strings was for others to challenge me and attempt to find faults in my logic. I lost that motive after repeated discussions only solidified my positions.
4. I feel like I've said everything I had to say. The physics of hang gliding hasn't changed, nor have my viewpoints, so I'd just be repeating myself with any further discussion.
5. Attitudes about weak links started shifting, so I felt less needed.

I've spoken out plenty in the past within HGT and HHPA and am still part of the local community, so that's not really a concern. I gave up on that front because it never went anywhere.

I still stop by Kite Strings on occasion even if I don't log in just to see if anything earthshattering is going on, though I don't have time to read everything. There's a lot of good information here, though, and I have no plans to stop supporting the site. Really wish you'd be more open to starting new threads, though. =)

Anyway, the reason I'm here now is I talked to Bart about Jeff's incident and have a few details to share. I asked if there was any evidence of thermal activity coming through the field at the time Jeff launched and he wasn't aware of any. He launched about a minute before Jeff and said launch conditions were easy with smooth air and little-to-no crosswind ('max 9 degrees' IIRC). It was a weak thermal day, not a day where dust devils would be a concern, and all pilots that flew reported easy launch conditions as well.

I didn't speak to anyone who witnessed the incident, but apparently Jeff was seen reaching for something with his left hand just after launch (before the lockout). Bart noticed at the crash site that Jeff's radio (on his left) was out of its pocket and wondered if there was an issue relating to it, but an investigator later reported removing it. Bart inspected Jeff's release and said it was in good condition.

Mitch Shipley is investigating.

That's all I know...

Zack

[miguel]

Thanks for all you have done here.
Your posts on hg.org were always lucid and easy to understand.
It is a shame that they purposely and willfully ignored the mouth release.

[Tad Eareckson]

Last evening got back from another wildlife oriented trip which had started rolling in the early morning of 2016/06/15. Ended up in pretty much the same shape I did on 2016/01/12 after Belize - exhausted and crippled.

This one was to the Rocky Mountain Front area of Montana west of Augusta and Choteau and then up to Glacier. Lotsa fairly short but steep and rough hikes but problems with endurance, lower back, circulation, foot made things tough and I experienced a lot of paralyzing pain.

And on Morning Two I discovered I had failed to throw the AC adapter into the bag during my Delta precipitated Morning One panic so my laptop was a brick from that point on and posting wasn't very practical with the iPad and I had zilch in the way of time and extra energy anyway.

Anyway...

Zack, real happy to see your first post in about a year and a half.

I simply got tired of the debates.

How I wish there were genuine debates in this sport. Instead we have two plus two equals four against opinion, ass covering, sabotage. But when we hit frauds like Rooney and Ryan hard and often enough they and their fan clubs disappear from the conversations.

My priorities have shifted and there are other things I want to spend time on.

But I have no actual life so here I remain.

I don't even read hanggliding.org or the Oz Report anymore.

Jack and Davis are u$hPa/Industry tools so don't tolerate posts and discussions of actual substance.

Lately I've been doing more triking than hang gliding anyway...think I flew in a few too many circles. =) (I'd actually really be up for some ridge soaring for a change, but both Quintana and Packsaddle are closed now.)

I did just the opposite. Went insane going back and forth, Highland Aerosports came to town in '99, light wind thermalling became practical for me and I was having a blast. Unfortunately that put my life in the hands of incompetent total assholes operating in flagrant violation of FAA regs and u$hPa SOPs in the most critical phase of the flight every time I went up and that situation was intolerable.

After seeing how stubbornly the general flying population clung to the status quo, my mentality drifted away from proactively trying to effect positive change to just doing what I think is safe and explaining the reasons to anyone curious.

Gotta wait until high profile fatalities like Zack Marzec and Jeff Bohl to get anything accomplished, otherwise all ya hear about are long track records.

Part of the reason I participated in discussions outside Kite Strings was for others to challenge me and attempt to find faults in my logic. I lost that motive after repeated discussions only solidified my positions.

So two plus two really DOES equal four and being a total moron is a prerequisite for being a u$hPa Member In Good Standing.

I feel like I've said everything I had to say.

Me too - untold thousands of times over. In REAL aviation the purpose of the weak link is to protect your aircraft against overloading and ya only need to state it once.

The physics of hang gliding hasn't changed...

But the history most assuredly has. And Kite Strings, being the only entity consistent with the physics of hang gliding, has been and is a major force directing that history.

...nor have my viewpoints, so I'd just be repeating myself with any further discussion.

That's OK, solid comments can be quoted and reposted as many thousands of times as one feels like.

Attitudes about weak links started shifting...

Standard aerotow weak link - biggest scam / Ponzi scheme...

http://groups.yahoo.com/group/hhpa/message/9360
Hook knives and other inventions

Zack C - 2010/02/04 01:07 UTC

I've had weak links break on aerotows for seemingly no reason a number of times. I feel that this is dangerous and am suspicious of the wisdom of using 130 lb Cortland Greenspot for every pilot in every configuration.

...in the history of aviation.

...so I felt less needed.

Let'em stew. They've finally gotten around to using heavier weak links for heavier gliders - which even the architect of the Infallible Weak Link had right three and a half decades ago - but they're still trying to use them as pitch and lockout protectors. I think it's an absolute riot comparing the hysteria about the stronglinks present in the Chris Bulger, Bill Bennett / Mike Del Signore, Robin Strid fatalities to the deafening silence about the Tad-O-Link that didn't break when it was supposed to and forced the 582 Dragonfly driver to squeeze his release lever when his tail started getting pulled around in the Jeff Bohl.

I've spoken out plenty in the past within HGT and HHPA and am still part of the local community, so that's not really a concern.

Just make sure you don't communicate with the FAA.

I gave up on that front because it never went anywhere.

It just went SOMEwhere. The percentage of Houston pilots flying pro toad with easily reachable bent pin releases just dropped a significant percentage.

I still stop by Kite Strings on occasion even if I don't log in just to see if anything earthshattering is going on, though I don't have time to read everything.

It's basically all reruns anyway. People keep doing the same things over and over expecting better results, we keep documenting them getting the same results.

There's a lot of good information here, though, and I have no plans to stop supporting the site.

It's a valuable archive, reference. Anybody wants to see every scrap of information available about the 2015/03/27 Kelly Harrison / Arys Moorhead, it's all here and pretty nicely consolidated.

Really wish you'd be more open to starting new threads, though. =)

Anybody who's been activated is free to start them, I just shy away from doing it myself. On that issue...

- I'm very grateful to other members who HAVE started a lot of the other topics and I wish Kite Strings were a lot less of the monologue that it is.

- This latest incident that I'm covering under "Weak links" was obviously a "Releases" issue when viewed from a purely nuts and bolts angle and I knew that from the first report. But I elected to cover it here because it's the decisive stake through the heart of three and a half decades worth of this weak link as the focal point of a safe towing system bullshit insanity.

If Zack Marzec and Jeff Bohl had swapped weak links there's a high probability that the former would've completed the tow and the latter would've been blown off when he failed to maintain the correct tow position (centered, with the wheels of the tug on the horizon, before he could've gotten into too much trouble. But not one single one of these Rooney Linking motherfuckers has whispered a single word along those lines because both of these PROFESSIONAL PILOTS were totaled on Quest's show and Quest CAN DO NO WRONG.

Anyway, the reason I'm here now is I talked to Bart...

The Bart whose bent pin release welded itself shut at about the same tension Jeff's was feeling around the time his Tad-O-Link increased the safety of the towing operation?

...about Jeff's incident and have a few details to share. I asked if there was any evidence of thermal activity coming through the field at the time Jeff launched and he wasn't aware of any.

And is barely aware of which way is up.

He launched about a minute before Jeff and said launch conditions were easy with smooth air and little-to-no crosswind ('max 9 degrees' IIRC). It was a weak thermal day, not a day where dust devils would be a concern...

Damn. Not much hope for another invisible dust devil write-off.

...and all pilots that flew reported easy launch conditions as well.

Guess they'd all been at an around all this plenty long enough to understand what's what and who's who.

I didn't speak to anyone who witnessed the incident...

As they've all been bought off.

...but apparently Jeff was seen reaching for something with his left hand just after launch (before the lockout). Bart noticed at the crash site that Jeff's radio (on his left) was out of its pocket and wondered if there was an issue relating to it, but an investigator later reported removing it. Bart inspected Jeff's release and said it was in good condition.

Just like...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3107
I have a tandem rating!!!

Lauren Tjaden - 2008/03/23 22:20:15 UTC

The barrel release wouldn't work because we had too much pressure on it.

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3391
More on Zapata and weak link

Paul Tjaden - 2008/07/22 04:32:22 UTC

I have never had a lockout situation happen so quickly and dramatically and had no chance to release as I have always thought I could do.

...Lauren's and Paul's before and after their flights. Really hard to find one of those that ISN'T in good condition. Hard to go wrong when you keep things simple.

Mitch Shipley is investigating.

I'm guessing the cause of death will be found to be the suffering of fatal injuries as a consequence of making no attempt to release.

That's all I know...

Thanks. Now Kite Strings has a little more than all of what all other members of the public knew.

Your posts on hg.org were always lucid and easy to understand.

And just look at all the positive changes they inspired over there.

It is a shame that they purposely and willfully ignored the mouth release.

As it has been with all other efforts to get stuff that doesn't stink on ice into circulation.

Oh well...

http://ozreport.com/forum/viewtopic.php?t=31052
Poll on weaklinks

Jim Rooney - 2013/03/03 19:37:19 UTC

My response is short because I've been saying it for years... and yes, I'm a bit sick of it.
This is a very old horse and has been beaten to death time and time again... by a very vocal minority.

See, most people are happy with how we do things. This isn't an issue for them. They just come out and fly. Thing's aren't perfect, but that's life... and life ain't perfect. You do what you can with what you've got and you move on.

But then there's a crowd that "knows better". To them, we're all morons that can't see "the truth".
(Holy god, the names I've been called.)

I have little time for these people.

It saddens me to know that the rantings of the fanatic fringe mask the few people who are actually working on things. The fanaticism makes it extremely hard to have a conversation about these things as they always degrade into arguments. So I save the actual conversations for when I'm talking with people in person.

A fun saying that I picked up... Some people listen with the intent of understanding. Others with the intent of responding.
I like that.

For fun... if you're not seeing what I mean... try having a conversation here about wheels.

Good to see Quest once again taking the lead on getting better equipment into the air after this one. Better late than never I always say.

[Tad Eareckson]

http://ozreport.com/forum/viewtopic.php?t=48131
We can and should have more directional control

Davis Straub - 2016/06/05 22:07:11 UTC

In autos in the US there is one fatal accident for every 100 million miles driven.
The last time we increased roll control we just extended the wings to get more performance by reducing induced drag.
Perhaps a hint at how we might go about getting increased roll control without going that route would be helpful.

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3107
I have a tandem rating!!!

Lauren Tjaden - 2008/03/23 22:20:15 UTC

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.

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3391
More on Zapata and weak link

Paul Tjaden - 2008/07/22 04:32:22 UTC

I have never had a lockout situation happen so quickly and dramatically and had no chance to release as I have always thought I could do.

http://ozreport.com/forum/viewtopic.php?t=24534
It's a wrap

Davis Straub - 2011/07/30 19:51:54 UTC

I'm very happy with the way Quest Air (Bobby Bailey designed) does it now.

Davis Straub - 2016/06/05 22:11:02 UTC

BTW, in aerotowing we pull on the VG almost half way or half way reducing further our roll control.

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?

Davis Straub - 2011/08/28 15:26:28 UTC

Then again, Russell Brown had us double up behind him after six breaks in a row at Zapata. We couldn't figure out why we had so many breaks so quickly. Maybe just coincidence.

Davis Straub - 2016/06/05 22:22:58 UTC

http://www.nytimes.com/2016/06/06/business/for-driverless-cars-citylike-test-sites-offer-the-unpredictable.html?_r=0

http://ozreport.com/forum/viewtopic.php?t=30971
Zach Marzec

Jim Rooney - 2013/02/16 05:05:41 UTC

Ok, keyboard in hand.
I've got a bit of time, but I'm not going to write a dissertation... so either choose to try to understand what I'm saying, or (as is most often the case) don't.
I don't care.

Here's a little bit of bitter reality that ya'll get to understand straight off. I won't be sugar coating it, sorry.
You see, I'm on the other end of that rope.
I want neither a dead pilot on my hands or one trying to kill me.
And yes. It is my call. PERIOD.
On tow, I am the PIC.

Now, that cuts hard against every fiber of every HG pilot on the planet and I get that.
Absolutely no HG pilot likes hearing it. Not me, not no one. BUT... sorry, that's the way it is.
Accept it and move on.
Not only can you not change it, it's the law... in the very literal sense.

Ben Reese - 2016/06/06 07:03:58 UTC

Before I logged in just now I was thinking the very same thing Steve "Dayhead" is saying. Even the best pilot is left helpless if they can't exercise roll control quickly at low altitude.

Really? So if hang glider roll control majorly sucks in general and totally sucks on tow then how come...

http://groups.yahoo.com/group/skysailingtowing/message/4633
Weaklinks and aerotowing (ONLY)

Steve Kroop - 2005/02/10 04:50:59 UTC

Davis,

Your weak link comments are dead on. I have been reading the weak link discussion in the OR with quiet amusement. Quiet, because weak links seem to be one of those hot button issues that brings out the argumentative nature of HG pilots and also invokes the "not designed here" mentality and I really did not want to get drawn into a debate. Amusement, because I find it odd that there was so much ink devoted to reinventing the wheel. Collectively I would say that there have been well over a 100,000 tows in the various US flight parks using the same strength weak link with tens of thousands of these tows being in competition. Yes I know some of these have been with strong links but only the best of the best aerotow pilots are doing this.

...Quavis puts the more highly skilled pilots up on less effective lockout protectors? Can somebody show me a shot of anybody exercising roll control more skillfully than this guy:

014-045415
http://c2.staticflickr.com/8/7337/27352666460_6e6bf9cb06_o.png


is? Feel free to use examples from Jeff and/or Davis Dead-On Straub.

As a sailplane pilot towing out of Truckee, CA I have been very close to emergency release even with full alieron and rudder control. The dynamics of the tow rope are very complex when things start going sideways.

Yes Ben. Misaligned thrust. Total rocket science.

The tug is an airplane and is moved through the air and controlled in it by different forces directing it on flight path. A Hang Glider is not a sail plane.

Course not. Sailplanes use releases that can be blown while maintaining...

31-B00050
http://c2.staticflickr.com/8/7658/27583391246_91c5048748_o.png


...full control of the aircraft, weak links proportional to the aircraft's max certified operating weight that protect it against overloading, and gently land on skids or wheels near the downwind end of the runway rather than violently whipstalling to dead-stop foot landings on the old Frisbee in the middle of the LZ or in narrow dry riverbeds with large rocks strewn all over the place.

Even if your flying free from tow flying close to terrain the glider can easily be overpowered by air currents pointing you at the mountain.

So it's a good thing to learn to fly upright with your hands at shoulder or ear height...

05-03223
http://farm8.staticflickr.com/7411/14165628916_bbdc682e28_o.png

08-43827
http://farm6.staticflickr.com/5120/14188732974_08536f5037_o.png

113-50017
http://farm6.staticflickr.com/5193/14002093889_95c09edf26_o.png


...for optimal roll control authority.

The best way to recover is increase speed...

So would it help to have...

07-03201
http://farm8.staticflickr.com/7200/14097626583_03972773c6_o.png


...a TWO point bridle with an upper attachment point on the keel to trim the nose down such that with the bar stuffed you're not just holding the glider down to tug level? Or is flying pro toad, the way Jeff was on his last flight, much safer - as Quavis insists it is?

...and get your weight on the side you want to turn on.

And ya wanna practice doing that with one hand so's to be properly prepared for Quavis brand hang glider aerotowing.

Often it is best to go in the direction the current is taking you while you increase speed then reverse your direction or choose another using the turn your forced with?

Go up to Cloud 9 and get Trisa to take you up for a few tandem training tows to learn how to do that properly.

This is a habit pilots get used to that must not be exercised while on tow.

Oh. Thanks for letting us all know that, Ben.

You must follow the tug or release...

...since with the crap that Quavis puts people up in it's physically impossible to do both at the same time - so pick one.

...and I can see no exceptions to this.

Yeah. That undoubtedly explains what went wrong with Jeff. His glider was easily overpowered by air currents pointing him away from where the tug was after it used its ailerons to whip a hard ninety, he instinctively went in the direction the current was taking him so that he could build up enough speed to enable crisp roll response and get back in line with the tug. He simply didn't understand that he either had to follow the tug or make the easy reach to the bent pin piece o' shit that Quavis had him put on his shoulder.

I may be wrong but my instincts tell me otherwise..

Can't go wrong listening to your instincts, Ben. And be sure to totally ignore three and a half decades of hang glider towing incident reports, data, common sense assessments.

This difference in HG'er Off tow flying and absolutely no go exception on tow could be a contributing factor as to why such experienced pilots enter a lockout and fail to release on time. A second or 2 more and they would realize the error but it's just to late so close to the ground.

Gee...

The United States Hang Gliding and Paragliding Association, Inc. - 2016/05/11
Standard Operating Procedure
12. Rating System
02. Pilot Proficiency System
11. Hang Gliding Special Skill Endorsements
-A. Special Skills attainable by Novice and above (H2-H5).
05. Aerotow (AT)

A Hang Two level Special Skill that can't be safely handled by a highly experienced and accomplished airline pilot.

-B. Special Skills attainable by Intermediate and above (H3-H5).
01. Assisted Windy Cliff or Ramp Launch (AWCL)
02. Turbulence (TUR)
03. Restricted Landing Field (RLF)
04. Cross Country (XC)
05. High Altitude Launch (HA)

Who'da thunk.

But isn't that why we always use an appropriate weak link with a finished length of 1.5 inches or less?

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?

Jim Rooney - 2011/08/28 10:40:24 UTC

I think what you're picking up on is my lack of willingness to discuss this with people that have already made up their minds.
Sorry for that, but it's just the nature of the beast.

I have no issue with discussing this with people that don't have an agenda.
I get very short with people that do however.

Am I "certain" about anything?
Nope.
However, some things get real obvious when you're doing them all the time. One is that weaklinks do in fact save people's asses.
You're 100% onto it... relying on the skill of the pilot is a numbers game that you'll lose at some point.

I find that so many people do not appreciate how fast and furious lockouts can happen.
They're exponential in nature.
Twice the time doesn't equate to twice the "bad"... it's four times the "bad"... then 16... it gets dramatic fast.

Is a weaklink going to save your ass? Who knows? But it's nice to stack the deck in your favour.

Now flip the argument and you start to see the devil.
A glider can take a whole shitload more force than a weaklink can.
So, if you're of the "sole purpose" cult, then you see no issue with a LOT stronger weaklink.

Well, it won't take long with that system before we've got a lot more dead pilots out there.
So they can stuff their philosophical purity bs... cuz I have no desire to tow someone to their death, no matter how willing they may be.

I'm not playing with this stuff in my head and just dismissing it. There's been a lot that's gone into this system.

I've seen too many people walk the "strong link" road only to find out the reality of things.
Fortunately, they've been unscathed, but there have been a lot of soiled underpants in the process.

I'm happy to discuss this stuff.
But I'm sick to death of arguing about it.

We relied the skill of the pilot - a numbers game that we lost at that point.

http://ozreport.com/20.102
The Quest Air Open Part 2

Davis Straub - 2016/05/22 02:26:08 UTC

Today we experienced a fatal aerotowing accident when a fellow pilot locked out very soon after coming off the cart. He plowed head first straight into the ground from too high right in front of us.

Fausto Arcos who was in the front of the launch line just in front of me watched the whole thing and said it was a "classic" progressive lockout. The pilot needed to release much earlier before it became non-recoverable.

Nobody appreciated how fastly and furiously the lockout was happening, we had an appropriate weak link with a finished length of 1.5 inches or less as mandated by Quavis, nearly half a decade more trail and error development had gone into that system since Jim Keen-Intellect Rooney had discussed this with us, the deck was stacked in his favour to the maximum extent possible...

Why do you think his ass wasn't saved? What more could possibly go into this system? We could use some kind of release that allowed the pilot to blow tow with BOTH hands on the basetube but that would necessitate increased complexity and increased complexity translates to increased failure rate so we'd end up killing ten times more pilots than we'd save. I'm not liking the looks of those numbers.

On tow close to the ground your going in the direction of the tug no matter what. Only a fast release...

...with one hand while maintaining max control authority with the other...

...will give you your own destiny on flight path.
If you go in direction counter to your tugs flight path, this will result in a lock out.

If only you could've explained all this to Jeff in time. And real bummer that the tug pilot was just as totally clueless at the same time. Did anybody get his name, experience level? Was he one of those banner jerkers used to just whipping stuff off the ground and flying wherever the fuck he felt like?

A sailplane can follow precisely the path of the tug. The nose hook is past the Forward CG and stabilizes the sailplanes natural tendency to follow the tug.

These dynamics are more complicated with Hang Glider and pilot being center of mass
with a moving CG. The tug pulls the pilot and the pilot pushes and pulls the glider..

So why not just use a...

http://ozreport.com/forum/viewtopic.php?t=9230
Departing the launch cart

Jim Rooney - 2007/08/24 12:20:06 UTC

Bad habit #1, not flying the glider... just letting the tug drag you around by the nose, combines with the fact that pro towing REQUIRES the pilot to do something (not let that bar move).

...three point bridal so you just let the tug drag you around by the nose? Not sporting enough?

There is allot going on and the fact that we do it somewhat safely is a real mystery.

But every once in a while we kill an airline pilot who's doing almost everything right but just doesn't really understand what's going on with a lockout. Maybe we should make this a Hang THREE and up level Special Skill.

A great deal of skill is required and displayed by both tugs and HG'er.

Bullshit. A great deal of skill is required to soar the dunes at Jockey's Ridge in light or turbulent air. There's ZILCH in the way of skill involved in aerotowing for the assholes at the front and back ends of the rope and you can't show me five seconds of video to provide the slightest degree of evidence to the contrary. Basic goddam Two level proficiency which is why AT is a basic goddam Two level Special "Skill".

But sadly at times no amount of skill is enough.

Total fucking asshole. Not a single mention of the pro toad bridle, easily reachable bent pin release, Tad-O-Link that didn't break when it was supposed to, tug driver who neglected to fix whatever was going on back there by giving the glider the rope until after the Tad-O-Link had kicked in. Totally detached from reality - ideal Davis Show Dedicated Sycophant.

[Tad Eareckson]

http://ozreport.com/forum/viewtopic.php?t=48131
We can and should have more directional control

Jeff Roberson - 2016/06/06 13:28:29 UTC

Steve Corbin - 2016/06/05 21:13:50 UTC

It's my firm belief that our current flex wing designs have adequate control for normal flying far from anything to hit. But in 40 years of flying a bunch of different gliders I've come to the conclusion that we don't have adequate control in many situations.

Here's a list of gliders I've flown during my 34 active years in this sport:
Spirit 180, Stratus VB 165, Comet 165, Comet 135, Comet II 165, Streak 165, Streak 135, Sensor A 165, Sensor B 155, Duck 135, Duck 165, Duck 180, ProAir 185, ProStar II 165, Magic III 177, Magic IV 166 (regular and full race), Magic 133, Axis 13, Vision 160, HP I 170, Sport 165, Glidezilla 155, Moyes Missile 190, K2 145, K2 155, K5 148, HP AT 158, Klassic 145.

In roll authority - THEY ALL SUCK! (Note that I'm a lightweight - under 140 lbs - and this is a big factor for roll control.)

Disclaimer: The most recent design I've flown is a PacAir Klassic 145. My buddy (who has over 4000 logged hours) says that the newer toplesses (e.g.Talon) roll much easier, but I simply don't believe him - the space truss structure and sail attachment configuration has not changed in any fundamental way at all.

p.s. I've never towed and never will - its simply too dangerous IMO.

Fuck you and your idiot opinion Jeff. The anecdotal evidence regarding and a basic common sense assessment of hill, mountain, cliff foot versus tow launch make the latter a no-brainer.

Bille Floyd - 2016/06/06 15:48:29 UTC

Steve Corbin - 2016/06/05 21:13:50 UTC

I've read too goddamned many reports of pilots dying or suffering serious injury due to this lock-out phenomenon.

@ Davis :
It almost kinda sounds like, your getting defensive on this one ? What could be bad, about more control ?

http://ozreport.com/forum/viewtopic.php?t=25550
Failure to hook in.

Bille Floyd - 2011/10/27 16:59:26 UTC

The Wind came back up and i picked up the glider & made a mental pre-launch check. Remembering that i had already hooked in previously --
i deleted the, "lift the glider" part to check for tension on the harness.
and signaled for the driver to GO !!

Jeff Roberson - 2016/06/06 16:16:38 UTC

Davis Straub - 2016/06/05 22:07:11 UTC

Perhaps a hint at how we might go about getting increased roll control without going that route would be helpful.

Something like this:



would greatly assist in accomplishing this:

Yeah Jeff, we'll all be holding our breath while you get that idea airborne and into widespread circulation. So many crash survivors are saying, "Shit! If only I'd had enhanced roll response in that situation.

Davis Straub - 2016/06/06 20:37:20 UTC

See if you can get Steven Pearson to give it a try.

You mean the Steven Pearson who's always wading into these disaster discussions and lighting the way forward? 'Specially when it's his glider designs...

19-04610
http://farm3.staticflickr.com/2809/13746340634_a74b33d285_o.png


http://farm8.staticflickr.com/7249/14019430712_8a80154df8_o.png
85-05328

http://c2.staticflickr.com/6/5788/23461251751_e98b9c7500_o.png


...involved?

No, I'm not being the slightest bit defensive.
Even now.

Suck my dick, Davis.

Ben Reese - 2016/06/07 06:01:27 UTC

Nice idea Ridgerunner.

Totally awesome. Amazing that in the entire history of hang gliding nobody else thought of anything along that line and attempted to get it airborne.

Trying to visualize the turn leverage and how the system helps you make a right turn?

Or we could just go with Atosses and their control surfaces.

If you go right the cable pendulum acctully pulls the sail tighter Reducing billow on the right? Should the initiation of a right turn increase billow reducing lift on the right and flatten sail on the left increasing lift on the left?

Your drawing is probably right but I am not seeing the details not shown out to the wing edges.

Just wait until he gets something airborne and produces a video. Everything will become glaringly obvious.

I was thinking about some kind of wing tip spoiler activated at extreme bar positions.

Like on an Atos?

Since the tips are out and behind the CG it seems the lift spoiling and induced drag would be very effective. Your lever action could also activate this system and change billow all in one control input..

Thanks, for sharing this and it seems I have seen it before?

Yes.

http://ozreport.com/12.083
Power steering

Over eight years ago and ZILCH as far as getting so much as a scale model produced. And how many lives have been ended or destroyed inside of that time span without Jeff doing jack shit about anything?

So...

- Anybody catch anything from Page 2 before Davis shredded this thread?

- Note that when Davis shreds yet another thread motivated by a desire to increase safety / put a dent in the fatality rate there's not a single whisper of protest anywhere from a single participant or reader.

[Tad Eareckson]

http://ozreport.com/forum/viewtopic.php?t=30971
Zach Marzec

Bill Cummings - 2013/02/28 06:11:37 UTC

I looked at the video ZC and what is not obvious is the type of bridle he was using.
I'm betting the pilot was not using a bridle to the keel release and that he couldn't hold the climb rate down while the truck was towing the pilot too fast.
What is obvious to me is that the pilot was using a very strong weaklink to be able to climb so fast with the keel more than 30 degrees to the horizon (even taking into consideration the tilted earth towing scenario).
When the pilot lost the towline it had the nose too high and due to that it climbed into a stall. My weaklinks would not allow me to climb that fast and develop into a stall like that.
Summery: I believe the strong weaklink breaking caused the stall and loss of control.
Now if you are going to say that the pilot should have been using an even stronger weaklink to stay on the line after seeing that climb rate it will prove beyond any reasonable doubt that you are in fact a ------------wait for it-----
INTERNET TROLL.

http://www.ushawks.org/forum/viewtopic.php?f=2&t=2527
Brainstorm, stop towline recovery chute entanglement.

Bill Cummings - 2016/06/25 14:20:12 UTC

Depending on the elasticity of a towline, releasing under much tension has proven to be a good way to instantly tie a bow or a knot in the falling towline. For this reason as well as not wanting to release into a climbing hammerhead stall I would always have the tow vehicle reduce (not totally) the line tension before releasing. I reduce tension for releasing while doing ST, (over land or water.) PL (over land or water.)

You're full o' shit, Bill. And Bob has the perfect forum/organization set up for you.

[Tad Eareckson]

Oops. How the hell did I manage to forget this one:

http://www.ushawks.org/forum/viewtopic.php?f=2&t=1563
Platform Launching (PL) Draft suggestions needed

Bill Cummings - 2014/06/05 19:44:19 UTC

The point here is if you are being towed into the air and not expecting that at any second you will be able to handle the loss of tow tension, YOU ARE DOING SOMETHING WRONG!

Bob Kuczewski - 2014/06/06 17:21:51 UTC

Great can of worms!!!!

I like the comparison between a release and a hang strap. That really drives home the point.

As forum moderator, I try to read every post on the forum. I know Tad has long pushed the "strong weak link" idea, and I'm glad to see the other side of the argument being presented.

I also like that this discussion emphasizes that breaking a weak link is something that can be practiced - just like we practice stalls - so we understand how to handle them and to not be afraid of them. I had a terrifying stall experience with my instructor when I was learning to fly airplanes back in the 70s. For a long time I feared getting close to stall. As long as I feared stalls, I was not spending much time getting comfortable with them, and that didn't make me a better pilot. So there's a lot to be said for safely learning to handle the inevitable rather than trying to come up with some way to avoid the inevitable.

Nice job Bill !!!!

Don't ever bother wasting your time registering over here, Bill.

[Tad Eareckson]

Hang Gliding - 2011/11

HigherEDUCATION

by Drs. Lisa Colletti & Tracy Tillman

THE ART AND ZEN OF LAUNCH CARTS

With appreciation and apologies to Robert Pirsig for yet another case of bromidic and platitudinous use of the title of his book: Zen and the Art of Motorcycle Maintenance [ref 1].

LISA: That picture reminds me of a Dharma wheel. Did you put our carts with the black cradles on one side on purpose?

TRACY: No, it just happened--seems like good cart Dharma Karma, I guess.

LISA: Ok, whatever. So, what does Zen have to do with launch carts?

TRACY: First, I think that every launch from a cart is spiritual and meditative, as it is a holistic experience that clears and centers the mind to a central focus.

LISA: Does that mean you have a mantra?

TRACY: I guess that you could say my mantra is "HIERTow," the acronym for our pre-launch checklist [ref 2]. I religiously go through it before every launch and maintain some level of awareness of it during the launch process.

LISA: I know what you mean about being focused, yet maintaining external awareness. It is important to maintain awareness of one's environment during launch, to avoid having to fix problems "on the fly," so to speak, while being focused on the details of the launch at hand.

I think that being able to focus on details while maintaining situational awareness is the Zen mastery part of flying.

TRACY: Also, it has been said that there is a little Zen involved in all authentic creative experiences [ref 3]. One example of that is the art of launch cart design.

LISA: You ought to know something about that. You were an engineer and manager in industry and taught engineering design and management as a professor for many years.

TRACY: Most engineering education is about teaching students how to apply science and crunch numbers to solve problems in theory. That science and math-based part of engineering design is necessary in our complex, technical world. However, engineering students have few opportunities to learn the art of using authentic experience to be creative and to solve real problems practically and pragmatically [ref 4], rather than just solving imaginary problems theoretically.

LISA: How did you teach your students to do that at the university?

TRACY: I provided an authentic creative experience to my students by establishing a holistic and practical learning environment for them. I did that by developing a series of junior and senior-level capstone classes that, all together, established an entire, integrated manufacturing business enterprise that required them to work together as departmental teams within classes and as a company across classes. Each year, the students initially performed a market study to identify a need or niche, followed by R&D and testing to create a working product concept, which they then would design for manufacture, develop a manufacturing system, mass produce, and sell. Profit made from one year's product sales would help fund a project for the following year. It was a thorough, integrated learning experience for them, as they learned not only practical design, but also practical project, teamwork, and business enterprise management skills.

LISA: One of your university students' most successful projects was the design and production of launch carts. You wrote an article about it for the July 1997 issue of Hang Gliding magazine [ref 5].

TRACY: Yes, that article described the students' model "A" cart design. A different group of students incorporated some additional design features and produced a model "B" cart the following year. We have been using both "A" and "B" model carts here at Cloud 9 for 15 years. Matt Taber now produces and sells a Lookout Mountain version of these carts [ref 6].

LISA: Our pilots really like those carts. What, in particular, are some features that make them a good design?

TRACY: First, the frame is wide enough, and the cradle supports for the base tube are high enough above the frame to provide clearance for almost any set of wheels commonly used on a hang glider, whether they are mounted on the base tube or as outrigger wheels that extend down and/or outside of the corner brackets.

LISA: We all know that smart aerotow pilots use wheels to help prevent a nose-over in case of a weak link break, line break, or premature release--or if they are pushed into the ground or settle to the ground just after launch due to a premature launch, downdraft, tailwind, or hitting the prop blast when just coming off the cart.

Other, more unusual causes of hitting the ground in front of the cart include getting stuck to the cart for some reason, aborting the launch due to realizing that you missed something important in your preflight check (like not in a leg loop), a tug engine power loss, or abort of the launch for some other reason by the tug pilot. There is no good reason for an aerotow operator to use a cart design that doesn't accommodate a reasonably wide range of wheels and wheel brackets that can be used on hang gliders. Although a wider cart is better, one simple fix for a narrow cart is to just use taller base tube cradles to provide more clearance above the cart frame for wheels on hang gliders.

TRACY: Another important feature of a good cart design is to be able to adjust the distance and height of the keel support relative to the base tube cradles, to provide clearance for hardware and a correct angle of attack (AOA) for a wide range of hang glider types and sizes.

LISA: Back when those carts were designed, in the mid-1990s, the students determined that the optimal AOA for a hang glider on a cart seemed to be about 25 degrees. It was found that most carts used by various aerotow operators around the country at that time provided for an AOA that ranged from 20 to 30 degrees. This is the angle as measured with an inclinometer placed on the keel, with the cart sitting on level ground. Some gliders from that time still had deep keel pockets; in that case, the angle would be measured with the inclinometer placed on the bottom of the sail.

TRACY: Right. So my students studied the dimensions of the smallest to the largest gliders produced at the time and designed a keel support to be adjustable from 20 to 30 degrees, for all glider sizes. Their recommendation at that time was that a 25-degree AOA was best.

LISA: Things have changed. First, you don't even need an inclinometer anymore--you can measure the AOA of your glider on a cart with your cell phone! Second, not many pilots are still aerotowing those old gliders with deep keel pockets. Third, almost all glider designs from the mid-1990s, basic through advanced, used luff lines and lots of washout, thus creating less total AOA relative to the keel, and as presented to the relative airflow while rolling on the cart. Today, advanced gliders are topless and/or use sprogs rather than luff lines and washout tubes for pitch stability, and thus have a flatter and tighter wing. And because these gliders tend to have high pitch pressure at low VG settings, pilots pull on a lot of VG to tow, all of which tightens the sail and creates more total AOA relative to the keel and as presented to the airflow. As a sail gets tighter and flatter, and has less washout and more total AOA, it should sit with the tail higher on the cart to present less AOA to the airflow while rolling on the cart.

TRACY: So today, a good AOA for most entry-level and low-intermediate gliders (as measured on the keel while sitting on the cart) is still about 25 degrees, but a good AOA (keel angle) for modern high-intermediate and recreational topless gliders seems to be about 22.5 degrees. The best AOA (keel angle) for very clean and tight competition topless gliders seems to be about 20 degrees.

LISA: Twenty degrees is still too much AOA on a cart for a modern rigid wing. Some rigid wing pilots have experienced lack of control when cart launching, as the wing is in a stalled condition or a wing's spoiler on is not effective because it is not in an area of clean airflow. Rather than reverting to foot launching, they should just fly off a cart with less AOA. We have found that a 15-degree keel-angle AOA is good for most rigid wings, and we have also had success with 12.5 degrees.

TRACY: Back in the old days, at the end of the last century, we found that we could just keep our carts set at one keel support height, and that all but the smallest gliders could be launched comfortably from those carts. If someone did have a very small glider, we would adjust the keel support to be lower for them, to help prevent them from sticking to the cart. As we acquired more carts, we found that we could just leave most of our carts set to a normal keel support height setting and just have one or two carts set to a lower setting for very small gliders. When we did that, we just marked the carts to be used for small gliders with red tape, so pilots with larger gliders would not use them.

LISA: As I said earlier, things have changed. Two standard height settings for our carts isn't good enough any more. Now, we use Black tape to mark carts with keel supports set very high for rigid wings (12.5 to 15 degrees AOA as measured on the keel), we use Blue tape to mark carts set high for comp flex wing gliders and large advanced gliders (20 to 22.5 degrees AOA as measured on the keel), we use Green tape to mark carts set for entry-level gliders and smaller to mid-size intermediate and advanced gliders (22.5 to 25 degrees AOA as measured on the keel), and Red tape for the smallest gliders (usually about 25 degrees AOA as measured on the keel).

TRACY: We are lucky to have enough carts on hand to not have to constantly adjust them for different glider models and sizes. Rather, we can leave the keel supports of our carts set at specific heights and color code them for use with certain gliders. Even if we didn't have that many carts on hand and had to adjust them from time-to-time, it would be useful to know the correct settings and color code them according to their adjustment. Obviously, a standardized, color-code system for cart settings would be helpful everywhere.

LISA: For sure. A standardized color code system would help pilots know they are on the right cart, no matter where they are aerotowing. Real bad things can happen if a pilot launches from a cart with the wrong AOA. Too high an AOA is a problem for rigid wings, just as it is for flex wings. With too much AOA, one side of a wing can be in a stalled condition at takeoff or be more likely to be lifted in a cross wind, either which can result in a high speed ground loop or lockout at launch.

TRACY: Too low an angle of attack is also a problem, as a glider may not want to lift away from the cart and can feel as if it is sticking to it. It may result in a very high speed take-off, longer ground roll and more likelihood of hitting the prop wash, and/or premature launch--with the glider being pulled forward off the cart rather than lifting away from it. This is particularly bad if you have a small glider with a long keel, as the tail of the keel will get lifted by the cart keel support as the glider gets pulled forward, thus lifting the tail, reducing the AOA, and pushing the glider down into the ground in front of the cart. Combine this situation with no wheels and perhaps an open face helmet, and the result ain't pretty.

LISA: We continue to hear reports about this kind of thing happening at comps and tow operations.

TRACY: What's up with that? Why do you think it continues to happen?

LISA: Insufficient aerotow training, lack of knowledge and ground school training on use of carts, and lack of standardization of cart settings. How about giving some examples of which gliders go on which carts?

TRACY: Sure. Our Black carts are set with our highest keel support setting for rigid wings like the Exxtasy and the Atos. Our Blue carts are set with a high keel support setting for topless gliders like the Litespeed RS 4/3.5, Litespeed 5/4.5, T2C 154/144, T2 154, Talon 160/150, and for kingpost gliders with very long downtubes like the U2 160, Sport 2 175, Falcon 225.

Our Green carts are set with a normal keel support height for topless gliders like the Litespeed 3 or 4, T2 144, Talon 140, Fusions, and mid-sized modern kingpost gliders like the U2 145, Sport 2 155, Sonic, Falcon 195/170, and most other older normal-sized kingpost gliders. Our Red carts are set with a short keel support setting for the very smallest topless gliders and small kingpost gliders with short downtubes, such as the Sport 2 135 and Falcon 140/145.

LISA: Are there any other features of your students' cart design that has made them work so well over the years?

TRACY: They are robust, utilizing a rigid triangular truss design, and have held up well over time; they are relatively lightweight, for quicker acceleration and lift-off; the base tube cradles are well back from the wheel axles, thus helping to avoid tipping over in ruts or bumps; they use sufficiently big 13-inch main wheels, so they roll easily and handle bumps well; the cut-out for the base tube in the cradles has a shape that securely holds a round or streamlined base tube, yet allows it to smoothly leave the cradle at lift-off; and the casters don't shimmy.

LISA: Tell us more about what causes casters to shimmy.

TRACY: First, there is more likelihood of shimmy at higher speeds and lighter loading on the caster, meaning casters are most likely to shimmy just about the time a pilot is about to leave the cart. It would be nice to just buy and use ready-made industrial casters--but they are designed with little caster angle, so they can support heavy loads, and they utilize ball bearings so they can rotate easily under a heavy load. At higher speeds and lower loads, industrial casters will shimmy due to insufficient caster angle and low friction of the ball bearings.

LISA: I recall that your students did some research on this.

TRACY: Right. They found that a brass or bronze bushing, rather than a ball bearing, for the vertical swivel bolt provides a nice bit of friction to help prevent shimmy, and that high-speed shimmy was reduced with more caster angle. Shimmy disappeared at a caster angle of about 40 degrees, and they found 45-and 50- degree angles to also work well--but the higher angles produced more friction and wear of the bushing, so they selected a 45-degree caster angle. This worked great throughout initial hang glider launch tests, as well as in very exciting high speed tests behind a pickup truck in the football stadium parking lot. Since then, that caster design has proven to work well over more than 15 years of service.

LISA: For folks who have these carts in service, are there any upgrades that you recommend?

TRACY: First, if you have a model "A" cart, it is good to replace the caster swivel bolt with a larger 5/8" diameter bolt, as used on the model "B" cart. The smaller bolt works just fine, but can end up bending a bit if heavy pilots stand on the cart or if pilots tend to pick it up and drop it a few feet from the air (which is poor launch technique). Also, it looks nicer and works a bit better if the pinch point protectors between the frame tubes of the model "A" cart are replaced with the style used on the model "B" cart, which are simply short PVC tubes cut at each end with a hole saw for snug fitting on the frame tubes.

LISA: Anything else?

TRACY: We have shortened the keel support posts above the keel rests on all the carts to provide more clearance for gliders that require horizontal stabilizers, but we made them even shorter on our Black carts that are used for rigid wings. We have also replaced the original cross rope and looped rope handles on the cradles with a flexible plastic tube, used as a handle. Use of a flexible plastic tube handle helps to prevent problems like an instrument lanyard cord, harness cord, or vg cord getting caught on the hold-down rope. We use a 12-inch-long, 5/8" outside diameter, bright orange plastic air line hose, fed snugly through a hole in the cradle where the original rope went through (2 inches below the basetube) and locked in place with a smooth round head carriage bolt screwed into the end of the hose that is in the cradle.

LISA: What about proper technique for launching off of a cart?

TRACY: In the earlier days of aerotowing, when most tugs had less power, acceleration, and climb rate than tugs use today, pilots were told to hang on to the cart until it was lifted a foot-or-two off the ground and then drop it, to assure that they had sufficient airspeed to fly and get clearance to climb away from the cart.

LISA: That approach still makes sense, if launching behind a very slow and very low-powered tug. But, most tugs now in service have much better performance. Also, a cart dropped from the air can bounce back up and hit or catch onto the pilot or glider, and the glider is likely to zoom up too high behind the tug, if it is flying fast when the cart is dropped.

TRACY: Right. So these days, the right time to let go of the hold down tubes and fly away from the cart is usually just prior to when the cart would be lifted off of the ground. It is not that difficult for a pilot to be able to feel when they are holding most (but not all) of the weight of the cart up by the handles, and know that it is time to release the handles to fly away from the cart.

LISA: Another issue is where your body should be positioned relative to the base tube while you are rolling on the cart. It usually works well to position the base tube about where it would be at best glide speed for your glider in free flight. That is close to being where the base tube will be while you are on tow, if your upper tow point is located in the correct position on your keel.

TRACY: However, there is no upper tow point when pro-towing, so there is nothing but your body weight to hold down the nose of your glider while launching and towing. In that case, you should hold your weight farther forward than at best glide speed when lying prone in the cart just prior to launch, because your body needs to be farther forward while towing. In fact, vertical lockouts are all too common with pro-towing, because sometimes pilots cannot move far enough forward to keep the nose down. A vertical lockout is very dangerous for both the tug pilot and the hang glider pilot.



LISA: Pilots should also realize that the cone of safety is much smaller when pro-towing than when using a normal 3-point aerotow bridle with an upper tow point, and that lockouts occur much quicker when pro-towing. For these reasons, we discourage pro-towing here at Cloud 9. It is a safety risk that some top comp pilots may wish to take for a miniscule amount of better high speed glide performance, but otherwise is a risk that just isn't worth taking for the vast majority of other pilots who aerotow.

TRACY: Another thing that we can talk about is crosswind cart launch technique. Pilots are required to get training on crosswind launch technique in order to get their AT rating. It's fairly simple. The pilot should just hold his/her weight an inch or two toward the upwind side of the wing while rolling on the cart, then center himself and fly the glider as necessary when leaving the cart. The more crosswind there is, the more the pilot should hold his weight over to the side while on the cart to keep the upwind wind down.

LISA: And then there is the issue of getting helped properly by a launch assistant.

TRACY: Right. Make sure the launch assistant is behind your side wires, and standing next to you--not behind you. It is difficult to communicate clearly with a launch assistant who is standing behind you, because you won't be able to see if he/she makes an incorrect or premature launch signal to the tug pilot if they are standing behind you. Therefore, ask your launch assistant to stand beside you, rather then behind you, before you give the "go, go, go" launch command.

LISA: Finally, we should mention the issue of stuff hanging out.

TRACY: Do you mean like a Tudor tube [ref 7]?

LISA: Not exactly, but if it is real long and hanging out, that would be a problem, too. What I'm talking about are things like VG cords, harness zipper cords, and anything else that dangles that could get stuck on the cart when launching.

TRACY: That includes feet. Some pilots launch with a foot hanging out of the harness, thinking that it will be quicker for them to get the other foot out and make a foot landing if their weak link breaks--or they are using their dangling leg to help bring their weight forward when pro-towing.

LISA: The smart approach is to not pro-tow, so you don't have to use a dangling leg to help keep your weight forward and the nose of your glider down. Also, you need to have wheels on your basetube, so you don't have to try to land on your feet if you have a weak link break close to the ground. Rather, with wheels on your basetube, you can keep your feet in your harness, while leaving your harness unzipped when you launch. That way you have the option of landing on wheels--if a weak link happens when you're very low--or you can do a foot landing, if higher. And you don't have to fumble around with trying to open your harness after the weak link breaks, because your harness leg doors are already open.

TRACY: Right. The problem with a dangling foot is that it is like a dangling harness or VG cord. A pilot's foot can get caught on the cart just like a dangling harness or VG cord. It happens; we've seen it.

LISA: And then the other problem is the Darwin Award approach of using launch carts--by lashing your glider to your cart to transport it across the field, then forgetting to undo the lash before launching. Just don't lash your glider to the cart. If it is so windy that you can't transport your glider across the field on the cart without lashing it to the cart, it's too windy to fly.

TRACY: A related, issue is mounting your instruments on to your glider when it is sitting on the cart and then lanyarding your instruments to both your glider and to the cart. That's another Darwin Award approach. That's not a Happy Ending.

LISA: Speaking of Happy Endings, it looks like we are done with this article. Since it's a bit windy for flying, you can take me on a date tonight and tow me up tomorrow.

TRACY: I'm up for that!!

Lisa is the Associate Dean and Professor of Surgery at the University of Michigan Medical School, and is currently Chair of the USHPA Towing Committee. Tracy is a retired university professor, a past Chair of the Towing Committee, and is currently Regional Director for Regions 7 & 13. He is also a FAAST Team Safety Counselor for the FAA Detroit FSDO area. They are both very active multi-engine commercial airplane and glider pilots, tug pilots, and tandem hang gliding instructors for the Dragon Fly Soaring Club at Cloud 9 Field (46MI), Michigan. Please feel free to contact them about towing related issues at cloud9sa@aol.com.

REFERENCES

1. Zen and the Art of Motorcycle Maintenance, by Robert Pirsig, 1974. Harper Collins.

2. HIERTow pre-launch checklist. In "Higher Education: How to Get the USHPA Aerotow Rating." by Lisa Colletti and Tracy Tillman, Hang Gliding and Paragliding magazine, July 2011, p. 24.
http://issuu.com/us_hang_gliding_paragliding/docs/1101_web?mode=embed&viewMode=presentation&layout=http%3A%2F%2Fskin.issuu.com%2Fv%2Flight%2Flayout.xml&showFlipBtn=true

3. http://en.wikipedia.org/wiki/Zen

4. http://en.wikipedia.org/wiki/John_Dewey

5. "University Students Launch a New Product." by Tracy Tillman, Hang Gliding magazine, July 1997, pp. 34-37.

6. Lookout Mountain Flight Park Launch Cart information:
http://estore.hanglide.com/Aerotow_Tow_Dolly_p/14-9011.htm

7. A tool used for relief on record-breaking flights, per Larry Tudor, distance record holder.

[Tad Eareckson]

Hang Gliding - 2011/11

HigherEDUCATION

by Drs. Lisa Colletti & Tracy Tillman

THE ART AND ZEN OF LAUNCH CARTS

TRACY: First, I think that every launch from a cart is spiritual and meditative, as it is a holistic experience that clears and centers the mind to a central focus.

Being prepared at every moment to recover from a standard aerotow weak link increase in the safety of the towing operation, rotate to upright, and execute a perfectly timed flare.

LISA: Does that mean you have a mantra?

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?

Jim Rooney - 2011/08/25 21:40:25 UTC

We know what we're doing.

Jim Rooney - 2011/08/26 17:34:33 UTC

Say it over and over and over in your head until it sinks in.

TRACY: I guess that you could say my mantra is "HIERTow," the acronym for our pre-launch checklist [ref 2].

Yeah. Everybody go to Reference 2 to find out what the fuck "HIERTow" means so's you can always be assured of a really safe launch and climb through the kill zone behind some total moron on a Dragonfly with all your Industry Standard equipment always within easy reach.

I religiously go through it before every launch and maintain some level of awareness of it during the launch process.

Great. Religion is definitely the name of this game so your religious beliefs and rituals should serve you quite well.

LISA: I know what you mean about being focused...

...yet maintaining external awareness. It is important to maintain awareness of one's environment during launch, to avoid having to fix problems "on the fly," so to speak, while being focused on the details of the launch at hand.

Of course, Lisa. That makes perfect sense to me. Probably to your students - like Tom Lyon - as well.

I think that being able to focus on details while maintaining situational awareness is...

...a total load o' crap.

...the Zen mastery part of flying.

And so in line with Jim Keen-Intellect Rooney's encyclopedia on landing perfection. All of our problems finally solved.

TRACY: Also, it has been said that there is a little Zen involved in all authentic creative experiences [ref 3]. One example of that is the art of...

..."aerotow release"...

06-02914
http://c2.staticflickr.com/2/1582/25806739256_8b0dc95171_o.png

08-03206
http://c2.staticflickr.com/2/1707/25806738026_c5b53178e3_o.png

10-03225
http://c2.staticflickr.com/2/1504/25711850432_5d577ba88c_o.png

14-04225
http://c2.staticflickr.com/2/1684/25532098020_9a643d13d2_o.png


..."design".

...launch cart design.

Fuck you, Trisa. That's at Wallaby but Webberville is pretty much home base for Bob (Grant) and he and other untold scores of assholes fly the same crap there. (And...

http://c2.staticflickr.com/2/1523/25679752020_89cc46e0e3_o.jpg


...great job, Quest.)

LISA: You ought to know something about that. You were an engineer and manager in industry and taught engineering design and management as a professor for many years.

http://groups.yahoo.com/group/skysailingtowing/message/4049
Towing errata

Bill Bryden - 2004/04/01 16:20:18 UTC

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 three hundred pounds to be modestly confident.

Maybe eight to ten 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 eighty to a hundred 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.

TRACY: Most engineering education is about teaching students how to apply science and crunch numbers to solve problems...

Dr. Trisa Tilletti - 2012/06

We could get into details of lab testing weak links and bridles, but this article is already getting long. That would be a good topic for an article in the future. Besides, with our backgrounds in formal research, you and I both know that lab tests may produce results with good internal validity, but are often weak in regard to external validity--meaning lab conditions cannot completely include all the factors and variability that exists in the big, real world.

...in theory.

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?

Jim Rooney - 2011/08/26 06:04:23 UTC

Hahahaha.
That seriously made me chuckle.

If someone's got a problem with it... we've got over ONE HUNDRED THOUSAND TANDEM TOWS and COUNTLESS solo tows that argue otherwise. So they can politely get stuffed.

As my friend likes to say... "Sure, it works in reality... but does it work in theory?"
Hahahahhaa... I like that one a lot

That science and math-based part of engineering design is necessary in our complex, technical world. However, engineering students have few opportunities to learn the art of using authentic experience to be creative and to solve real problems practically and pragmatically [ref 4], rather than just solving imaginary problems theoretically.

Oh. So you looked at the state of aerotowing and immediately realized that the most critical problem we had was with our...

http://www.hanggliding.org/viewtopic.php?t=11497
Aerotow release options?

John Glime - 2009/04/13 18:09:32 UTC

Rick,

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.

http://www.questairforce.com/aero.html
Aerotow FAQ

Quest Air
Equipment and Accessories
Weak Link

The strength of the weak link is crucial to a safe tow. It should be weak enough so that it will break before the pressure of the towline reaches a level that compromises the handling of the glider but strong enough so that it doesn't break every time you fly into a bit of rough air. A good rule of thumb for the optimum strength is one G, or in other words, equal to the total wing load of the glider. Most flight parks use 130 lb. braided Dacron line, so that one loop (which is the equivalent to two strands) is about 260 lb. strong - about the average wing load of a single pilot on a typical glider. For tandems, either two loops (four strands) of the same line or one loop of a stronger line is usually used to compensate for nearly twice the wing loading. When attaching the weak link to the bridle, position the knot so that it's hidden from the main tension in the link and excluded altogether from the equation.

IMPORTANT - It should never be assumed that the weak link will break in a lockout.
ALWAYS RELEASE THE TOWLINE before there is a problem.

...launch carts. Excellent job of prioritization there, Trisa.

LISA: How did you teach your students to do that at the university?

Beats the fuck...

Dr. Trisa Tilletti - 2012/06

What we have covered in this article is practical information and knowledge gleaned from the real world of aerotowing, developed over decades and hundreds of thousands of tows by experts in the field. This information has practical external validity. Hopefully, someone will develop methods and technology that work better than what we are using as standard practice today. Like the methods and technology used today, it is unlikely that the new technology will be dictated onto us as a de jure standard. Rather, to become a de facto standard, that new technology will need to be made available in the marketplace, proven in the real world, and then embraced by our sport.

...outta me.

TRACY: I provided an authentic creative experience to my students by establishing a holistic and practical learning environment for them.

Ever think about trying something like that in hang gliding?

I did that by developing a series of junior and senior-level capstone classes that, all together, established an entire, integrated manufacturing business enterprise that required them to work together as departmental teams within classes and as a company across classes. Each year, the students initially performed a market study to identify a need or niche, followed by R&D and testing to create a working product concept, which they then would design for manufacture, develop a manufacturing system, mass produce, and sell. Profit made from one year's product sales would help fund a project for the following year. It was a thorough, integrated learning experience for them, as they learned not only practical design, but also practical project, teamwork, and business enterprise management skills.

Meanwhile US hang gliding, under total control of its non pilot corporate lawyer, is headed towards extinction.

LISA: One of your university students' most successful projects was the design and production of launch carts. You wrote an article about it for the July 1997 issue of Hang Gliding magazine [ref 5].

TRACY: Yes, that article described the students' model "A" cart design. A different group of students incorporated some additional design features and produced a model "B" cart the following year. We have been using both "A" and "B" model carts here at Cloud 9 for 15 years. Matt Taber now produces and sells a Lookout Mountain version of these carts [ref 6].

Matt Taber - 2009/07/12

GT Manufacturing Inc. (GT) and Lookout Mountain Flight Park Inc. (LMFP) make no claim of serviceability of this tow equipment. There is no product liability insurance covering this gear and we do not warrant this gear as suitable for towing anything. We make no claim of serviceability in any way and recommend that you do not use this aerotow gear if you are not absolutely sure how to use it and or if you are unwilling to assume the risk. Towing and flying hang gliders is inherently dangerous.

LISA: Our pilots really like those carts.

Despite their relatively short track records? Go figure.

What, in particular, are some features that make them a good design?

They're within easy reach.

TRACY: First, the frame is wide enough...

Oh! So WIDE is a good thing. So don't you defeat the purpose to a significant extent...

02-0926
http://c2.staticflickr.com/8/7627/27788503732_62b4191a6a_o.png


...by setting the basetube cradles at shoulders width?

13-1921
http://c2.staticflickr.com/8/7433/27277536864_6c0ea23ca9_o.png

...and the cradle supports for the base tube are high enough above the frame to provide clearance for almost any set of wheels commonly used on a hang glider, whether they are mounted on the base tube or as outrigger wheels that extend down and/or outside of the corner brackets.

Outrigger wheels...

http://farm8.staticflickr.com/7597/16975005972_c450d2cdda_o.png


Always a great idea for hang glider towing ops.

http://c2.staticflickr.com/6/5788/23461251751_e98b9c7500_o.png

LISA: We all know that smart aerotow pilots...

...have either been threatened to shut the fuck up about what they're seeing or blacklisted out of the sport.

...use wheels to help prevent a nose-over in case of a weak link break, line break, or premature release-

Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974

"The greatest dangers are a rope break or a premature release."- Richard Johnson

REALLY smart hang glider pilots don't tow with flimsy crap between themselves and the tug or behind total douchebag drivers who can fix whatever's going on back there by giving them the rope - ya dumb bitch.

-or if they are pushed into the ground or settle to the ground just after launch due to a premature launch...

Smart aerotow pilots don't launch prematurely. I don't even know of any stupid aerotow pilots who launch prematurely. The stupid ones tend to stay on the cart way too fuckin' long.

...downdraft...

Yeah smart aerotow pilots... Ya just never know when one of those downdrafts is gonna push you into the ground as you're coming off the cart.

...tailwind...

- There's no such thing as a relative tailwind as one approaches takeoff speed on aerotow.

- So you eat up more time, runway getting to takeoff speed with a tailwind - just like you do with a less powerful tug, higher density altitude. Big fuckin' deal. Not an issue for anyone who has any business being hooked up behind a tug.

...or hitting the prop blast when just coming off the cart.

Prop blast... Tears your wings off and/or breaks your standard aerotow weak link plus causes you to settle into the ground. I think another Higher Education article is needed.

Other, more unusual causes of hitting the ground in front of the cart include getting stuck to the cart for some reason, aborting the launch due to realizing that you missed something important in your preflight check (like not in a leg loop), a tug engine power loss, or abort of the launch for some other reason by the tug pilot.

Bullshit.

There is no good reason for an aerotow operator to use a cart design that doesn't accommodate a reasonably wide range of wheels and wheel brackets that can be used on hang gliders.

But...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3107
I have a tandem rating!!!

Lauren Tjaden - 2008/03/23 22:20:15 UTC

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.

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3391
More on Zapata and weak link

Paul Tjaden - 2008/07/22 04:32:22 UTC

I have never had a lockout situation happen so quickly and dramatically and had no chance to release as I have always thought I could do.

http://www.hanggliding.org/viewtopic.php?t=21033
barrels release without any tension except weight of rope..

Bart Weghorst - 2011/02/25 19:06:26 UTC

Most of the time. But I've had it once where the pin had bent inside the barrel from excessive tow force. My weaklink was still intact. The tug pilot's weaklink broke so I had the rope. I had to use two hands to get the pin out of the barrel.
No stress because I was high.

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?

Davis Straub - 2011/08/28 15:26:28 UTC

Then again, Russell Brown had us double up behind him after six breaks in a row at Zapata. We couldn't figure out why we had so many breaks so quickly. Maybe just coincidence.

No problem whatsoever.

Although a wider cart is better, one simple fix for a narrow cart is to just use taller base tube cradles to provide more clearance above the cart frame for wheels on hang gliders.

Hey Trisa... If wheels, skids are such big fuckin' deals in aerotow launch/landing then how come you don't make them mandatory? Name one operation from the history of the sport - club, commercial, comp - in which wheels, skids have been required.