Departing the launch cart
Jim Rooney - 2007/08/24 12:20:06 UTC
Bad things...
Having to push out of the cart.
Your AOA is too high or you're pulling in (or both!).
If you're having to push out when pro-towing (and your cart AOA is right), then you're allowing yourself to get pulled through the control frame. This is an easier mistake to make pro towing as YOU must transmit all the energy of the tow to the glider (through your hang strap). In three point towing, 1/2 the energy is transmitted to the glider, 1/2 to you. In pro towing, you're it.
The tug will "want" to pull you through the bar.
If you let it, you're essentially pulling in.
All result in leaving the cart at too high a speed.
Why is this bad? I thought speed was good?
Too much of anything is bad.
You pretty much guarantee that you will slam into the propwash. Not only does this make the glider harder to control (you're now swiming in the rapids instead of a calm lake), it tends to help break weaklinks.
This is normal everyday highspeed cart exit.
Taking things a bit further...
Take the "I shouldn't need to do anything on tow" mentality (UHG!) and mix it with transitioning to pro towing.
This gets really interesting really fast.
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). So instead of holding the bar where it is, bad habit pilot just lets the tug pull him. This pulls him through the control frame with the same effect as the pilot pulling in... a LOT.
I've seen gliders go negative while still on the cart this way.
The results are never pretty.
Ok, on to a less dramatic (and much more prevalent) problem...
Taking the cart with you, then dropping it.
This comes from 582s vs 914s and crosswind launching with bad AOAs.
582s take longer to get you to flying speed.
Bad AOAs in crosswinds have you at high AOAs and low speed (dangerous).
The two combine to put you in harms way longer.
So the idea of holding the cart till it's lifted off the ground was born.
Not a bad hack solution.
If I'm out in a crosswind with a WW glider and an old style cart (no AOA adjustment), I'd probably do the same.
But we have better equipment these days.
With a proper AOA, you should simply slide out of the cart... no need to take it flying with you. I teach students to feel for the glider tugging against the rope and let the rope slide out of their hands.
So what's the bad side of holding on?
Behind a 582, not much.
Behind a 914, it gets a bit more exciting.
Your wingloading is changing dramatically.
Behind a 582, you're not accelerating nearly as fast as a 914.
Things happen faster.
Holding on a second too long now has dramatic results.
You wind up slaming into the propwash at the same time you're radically altering your wingloading (dropping a 100lbs).
I can't count the number of weaklinks I've seen break due to this alone.
It's not a horrible problem, but it just makes me shake my head.
Jim Rooney - 2007/08/26 11:34:17 UTC
582 technique... let me explain
Yes, it's the accelleration. 115hp gets you flying much quicker.
Add to this the fact that it's a 4 stroke engine so it develops power imediately. A 582 has to spool up. It develops power much more gradually.
That transitional time in the cart where the glider is flying, but just barely, gets extremely short behind a 914.
Where as with a 582, it's a noticeable thing. With a 914, it's over in an instant.
So waiting till you're lifting the cart, which can help behind a 582, can actually become a hindrance behind a 914.
See in the window for holding the cart "a few inches" becomes an instant... then you're in the 'radically cahnging your wingloading' arena.
You'd have to get a pretty knarly wind shift behind a 914 for it to matter... you're accellerating around twice as fast.
I see people that are used to flying behind 582s breaking weaklinks behind 914s all the time.
The worst are people that pull in a bit "for sufficient flying speed", then push out of the cart (that never goes well).
Consider footlaunching for example.
Footlaunching has a much more distinct "akward" time, where the glider is flying but not fully supporting your weight.
Behind a 582, you get to 'moon walk' a long time.
Behind a 914, as soon as you start to moon walk, I litterally yank you off the ground (I add power). A 582 hasn't yet spoolled up enough to do this.
Jim Rooney - 2007/08/30 10:26:08 UTC
Yes, you can leave the cart too early, even behind a 914 (you just have to try harder), but guess what? You can leave late too. And more often than not, people used to 582s that get behind 914s do so, then they break weaklinks at 5 feet off the ground because they fail to adjust thier techniques to match the launch conditions. The regularity of this is saddening.
After the first couple weaklinks, they ask what's up (most often in the form of "can we tow slower?"... or my personal favorite "Why can't I use two weaklinks?") when I explain to them that taking the cart into the air with them might be counterproductive... that towing behind a 914 isn't the same as a 582... Then, amazingly, they stop breaking weaklinks.
Jim Rooney - 2007/08/31 12:57:14 UTC
If you forget to "resist the tug", as I put it (holding that bar in position prevents you from getting pulled through), the tug will pull you through the control frame while you're waiting for the keel to rotate.
Behind a 582, not too big of a deal.
Behind a 914, things get a bit more dramatic.
As the keel rotates, you're now essentially pulling in even more (the glider's nose has come down relative to you). You're behind a 914, so it accelerating at a very rapid pace. This extra speed "pins" you to the cart. Now you have to push out to get out of the cart. Now, you're at a high AOA, going a million miles an hour straight into the propwash. Or the glider goes negative and you faceplant.
I'm not speaking of theory here. I see this crap a lot.
It generally starts with someone that's been behind 582s.
I very often hear "I pull in a tad on the cart and wait for it to get lifted off the ground" a lot too (582 technique) when I discuss why someone's breaking weaklink after weaklink at 5ft in smooth morning air.
Jim Rooney - 2007/09/01 02:39:53 UTC
First off I guess is that a simple conversation fixes the problem, or the problem is unfixable.
Let me explain.
See one side is lack of information, the idea that 914s require a different launch technique.
The other is a pilots willingness to adjust.
The first is easily solved with a simple conversation but only if the second is possible.
See, there's no 'learning curve'. You either wait stubbornly till you're lifting the cart, cuz "that's the 'right' way", or you don't. The timing is easy. You actually have to work hard to leave the cart at the wrong time (early or late).
In the end, it really does boil down to a willingness to adjust.
It's not a skill thing. The timing is exceptionally simple. 1st time solos do it all the time.
It's as simple as saying "I'm going to let the glider fly out of the cart when it starts tugging on the handles/rope instead of insisting that the cart becomes airborn before I let go."
And ALL OF OUR ROONEY LINK INCONVENIENCE PROBLEMS are OVER.Jim Rooney - 2008/05/04 10:50:46 UTC
That "pop" out of the cart is cuz one of two things.
A) you're lifting the cart into the air and dropping a couple hundred pounds when you let go... might have a bit of an effect eh?
B) you're hitting the propwash of the tug.
Snapping weaklinks because of "thrust"
Yeah, that hits on the "how" a bit...
That thrust is applied smoothly. What you're doing with it isn't.
Smooth will not break weaklinks.
In the end, you're achieving the same tow force. With a 914, you're getting there faster.
This is why I say towing behind a 914 takes a different technique.
Behind a 582 you're free to make all kinds of sharp corrections... you can get away with it. Not so on a 914.
When I see someone breaking weaklink after weaklink... they're always hamfisting something.
Hanging onto the cart and dropping it "pops" you because you're dropping a few hundred pounds... you radically alter your wingloading. This is the same as pushing out sharply. Yeah, that puts a sharp load on the weaklink. People get away with it behind a 582 most of the time (I've seen 'em botch that up too, just not as often) because you're not accellerating as quickly.
With faster acceleration, everything happens faster so everything you do is amplified. So little things like a "small push" become a big push even though you haven't "done anything differently". It's the same as getting in your car and starting to drive normally... now think of doing the same while stomping on the gas... every little twitch matters.
http://ozreport.com/forum/viewtopic.php?t=31052
Poll on weaklinks
Problem solved.Jim Rooney - 2013/03/05 21:40:02 UTC
You want MORE.
I want you to have less.
This is the fundamental disagreement.
You're afraid of breaking off with a high AOA? Good... tow with a WEAKER weaklink... you won't be able to achieve a high AOA. Problem solved.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=2467
weak links
Doesn't sound like the problem had been solved under 32 days prior to your entry into the "Departing the launch cart" thread. You're not coaching the million hamfisted comp pilots on how to not be hamfisted when they're slaming into the hogwash. You're just telling them to suck it up so you won't hafta operate as a test pilot towing tandem aerotow weak links on gliders with too few people underneath them.Jim Rooney - 2007/07/22 22:30:28 UTC
I've heard it a million times before from comp pilots insisting on towing with even doubled up weaklinks (some want no weaklink). I tell them the same thing I'm telling you... suck it up. You're not the only one on the line. I didn't ask to be a test pilot. I can live with your inconvenience.
And obviously these Rooney Links are blowing all the fucking time and...
http://www.chgpa.org/forums/viewtopic.php?f=2&t=3600
Weak link question
...saving scores of tug pilot lives every month 'cause if that wasn't happening then why would they all be that rabid about not allowing solos to fly on standard tandem aerotow weak link? Like with guns to their heads they'd never consider driving a couple miles to the grocery store with their seatbelts unbuckled 'cause they have serious head on collisions two or three times a week and the seatbelts are making the difference between flying through the windshields and walking away smelling like roses.Jim Rooney - 2008/11/24 05:18:15 UTC
BTW, if you think I'm just spouting theory here, 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.
And...
http://www.chgpa.org/forums/viewtopic.php?f=2&t=6408
Highland : Party Sat Oct 25 & Seminar Spring 2015
You were there at Hiih Gland Aerosports through the 2015 season during which Hiih Gland never presented the "must attend" for all who fly at Highland or tow elsewhere seminar that covered the science and art of staying on tow in both smooth and thermic air. (Funny they didn't say anything about behind both 582s and 914s - the way you didn't say anything about both smooth and thermic air.)Ward Odenwald - 2014/08/30 01:44:02 UTC
To enhance towing safety, Highland will present a seminar that covers the science and art of staying on tow in both smooth and thermic air at the beginning of the 2015 season (3rd or 4th Saturday of March). This learning event should be considered a "must attend" for all who fly at Highland or tow elsewhere!
And Hiih Gland won't be hosting this learning event at the beginning of the 2016 season either. The knowledge of the science and art of staying on tow in both smooth and thermic air for those who flew at Hiih Gland and tow elsewhere...
http://www.chgpa.org/forums/viewtopic.php?f=2&t=6326
An OK Day at Ridgely
...has died with them and now the remaining AT universe is just shit outta luck.Matthew Graham - 2014/06/09 01:51:11 UTC
It was pretty quiet at Ridgely when we arrived at noon. Brian VH and Felix were there-- and Sammy (sp) and Bertrand... and Soraya Rios from the ECC. She was not flying.
Felix test flew Bertrand's T2C for about an hour and loved it. Brian had a short flight on a Falcon. I got on the flight line at a little after 1pm behind Sammi. She had a sledder. Then the tandem glider called rank and went ahead of me. The tandem broke a weak link and it took a while to sort out a new weak link. I finally towed around 1:30 and also broke a link at 450'. Back to the end of the line. Actually, my wife Karen let my cut in front of her. Bertrand and Sammi towed again. Each having sledder. The cirrus had moved in and things did not look good. Again I arrived at the front of the line only to have the tandem call dibs. And then the tug needed gas. I thought I would never get into the air...
Jim Rooney - 2007/09/01 02:39:53 UTC
I don't tow solos under full power... you could't keep up with me if I did. I wouldn't be going faster horizontally, but my accelleration and climb rate would be so extreme that most pilots couldn't keep up the timing needed to make it work. (I think Bo's the only one I've successfully towed at full boost)
Which brings us to the reason to have a 914 in the first place... you need one.
Something made you get a 914 instead of a 582. 914s are horribly expensive to own and maintain. If you own one, you need it... it's a safety thing. Short runways, tall trees, whatever. You've got a 914 to increase your safety margin. So when it comes down to my safety or having a conversation, we're going to have a conversation. Wether you chose to adjust is then up to you.
That's smoking gun GOLD. Highland's gonna present this "MUST ATTEND" seminar that covers the SCIENCE and ART of staying on tow in BOTH SMOOTH AND thermic air at the beginning of the 2015 season because...Jim Rooney - 2007/09/04 12:47:39 UTC
The cost of maintenance depends heavily on if you can do it yourself and if you're a club or business.
582 maintenance is pretty easy stuff, but will cost you if you have to pay for it.
914 stuff is harder and will cost you dearly if you can't do it.
582s typically break cheaper than 914s. The whole engine's not that expensive to start with... even a crankshaft isn't bad compared to the crap that breaks on a 914 (like the turbo). When a 914 breaks, open your wallet.
Here's the business part.
Downtime becomes money. With the low cost of the engine, it's easier to have a ready to go spare on the shelf. You can swap a 582 in about 1/2 hour. Try that with a 914. When they break, the plane is typically down for the day (at least)
http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
...they can't get any gliders airborne in soaring conditions. They've got all the expenses of 914s but they've gotta fly them as 582s and they're beating the crap out of them with zillions of extra launch and landing cycles doing "free" relights all season long.Jim Rooney - 2011/08/28 19:39:17 UTC
Weak links break for all kinds of reasons.
Some obvious, some not.
The general consensus is the age old adage... "err on the side of caution".
The frustration of a weaklink break is just that, frustration.
And it can be very frustrating for sure. Especially on a good day, which they tend to be. It seems to be a Murphy favourite. You'll be in a long tug line on a stellar day just itching to fly. The stars are all lining up when *bam*, out of nowhere your trip to happy XC land goes up in a flash. Now you've got to hike it all the way back to the back of the line and wait as the "perfect" window drifts on by.
I get it.
It can be a pisser.
But the "other side"... the not cautions one... is not one of frustration, it's one of very real danger.
Better to be frustrated than in a hospital, or worse.
No exaggeration... this is the fire that the "other side" is made of. Best not to play with it.
Great business model. How many people would be spending two, four hours on the road on a great soaring conditions Saturdays for four minute sleds because they'd only be permitted to launch in dead cycles. "The snow conditions are FANTASTIC today and you'll be able to have awesome speed runs. So we're gonna make sure you're bindings are really loose to make sure you have extra wide safety margins."
That "must attend" seminar was a desperation move to try to stem the operating cost bleed-out. But here's the "must attend" seminar that covers the science and art of staying on tow in both smooth and thermic air:
OK. Any questions? No? Cookies and lemonade on the table at the back of the room. You've been a great audience, thanks for coming and for your attentiveness.Davis Straub - 2011/08/26 14:04:52 UTC
...go ahead and double up (four strands of Cortland Greenspot).
Tad Eareckson - 2008/11/15 22:49:17 UTC
A DOUBLE loop of Greenspot IS a pretty good one size fits most. It would max out Karen at 2.0 if she towed one point but only puts her at 1.74 as is and it puts me and Janni at 1.09, 1.25 off the shoulders.
Jim Rooney - 2011/08/25 04:55:25 UTC
It always amazes to hear know it all pilots arguing with the professional pilots.
I mean seriously, this is our job.
We do more tows in a day than they do in a month (year for most).
We *might* have an idea of how this stuff works.
They *might* do well to listen.
Not that they will, mind you... cuz they *know*.
I mean seriously... ridgerodent's going to inform me as to what Kroop has to say on this? Seriously? Steve's a good friend of mine. I've worked at Quest with him. We've had this discussion ... IN PERSON. And many other ones that get misunderstood by the general public. It's laughable.
Don't even get me started on Tad. That obnoxious blow hard has gotten himself banned from every flying site that he used to visit... he doesn't fly anymore... because he has no where to fly. His theories were annoying at best and downright dangerous most of the time. Good riddance.
http://ozreport.com/forum/viewtopic.php?t=30971Jim Rooney - 2011/08/26 23:12:32 UTC
He has been banned from every flying site he's ever set foot at and some he hasn't.
And yes, he is a deranged megalomaniac.
I had the displeasure of having to put up with him before he was kicked out of one of the flight parks that I was working for.
Good riddance.
Zach Marzec
For saying double up your idiot fucking Rooney Links you IDIOT FUCKING MORONS - before the science and art of staying on tow in both smooth and thermic air had adequately evolved and the accepted standards and practices had changed.Jim Rooney - 2013/03/07 18:24:58 UTC
You're the one advocating change here, not me.
I'm fine.
These are only questions if you're advocating change. Which I'm not. You are.
You're the one speculating on Zack's death... not me.
Hell, you've even already come to your conclusions... you've made up your mind and you "know" what happened and what to do about.
It's disgusting and you need to stop.
You weren't there. You don't know.
All you have is the tug pilot report, who himself says he doesn't know... and HE WAS THERE... and he doesn't know.
Ever heard of "Confirmation Bias"?
Because you're a textbook example.
You were out looking for data to support your preconceived conclusion, rather than looking at the data and seeing what it tells you... which is why this is the first time we've heard from you and your gang.
Go back to Tad's hole in the ground.
While you're there, ask him why he was banned from every east coast flying site.
That fuckin' fishing line and all the waste, carnage, insanity that it and its perpetrators wreaked - and the related contempt for the recreational pilot and his safety - was what killed Ridgely - above all other factors.
http://groups.yahoo.com/group/skysailingtowing/message/4593
Weaklinks
Suck my Peter, dick.Peter Birren - 2005/02/08 19:22:49 UTC
What is the big issue? Re-launching? Oh, the wasted time! Oh, the hassle! Oh, the embarrassment! These are sure preferrable to Oh Shit!
