Departing the launch cart - Davis Show

General discussion about the sport of hang gliding
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Tad Eareckson
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Departing the launch cart - Davis Show

Post by Tad Eareckson »

http://ozreport.com/forum/viewtopic.php?t=9230
Departing the launch cart
Davis Straub - 2007/08/23 14:58:11 UTC

http://ozreport.com/11.167
2007 Worlds - nobody died
Davis Straub - 2007/08/23 14:58:11 UTC

The one accident that happened on the line came when a pilot had taken off his wheels (he was the only pilot flying with wheels) and when he came off the cart slow and too early. His English wasn't good so he may not have understood the requests for him to hold on and he was one of the least experienced pilots at the Worlds.
Yeah Davis, awesome write-up of the Big Spring safety issues and the awesome job y'all did building safety into your system. The more of your dedicated sycophants who hear about it the better off they and the sport will be.
Bill Jacques - 2007/08/23 23:11:27 UTC
Boca Raton

I find this interesting because over my last two years of aerotowing (over 100 tows now) I have twice forgotten to grab on to the rope/hose(s) prior to the commencement of towing.
Where was this and who was launching you?
It's one of those "Oh Sh&t!" moments as the cart starts accelerating and you can't reach down and over in front of the basetube and cart to grab onto the rope/hose(s) with any type of safety.
- Don't worry. The weak link will break before you can get into too much trouble.
- Just hold the fuckin' bar back and wait until your glider's flying.
Each time, the glider came off the cart on its own and I pushed forward to make sure it gained a couple feet of altitude relatively quickly (which, thankfully, happened!).
Yeah. Whenever you're afraid you may not have enough airspeed push out a little bit to find out for sure.
Within a long second, the glider was flying fast enough to be very controllable.
:roll:
As I am flying a Falcon 3, does this "automatic" liftoff at controllable speed not happen to the higher performance wings?
No. They're totally different beasts. You need to fly upper intermediate gliders for years to gain any useable understanding of how toplesses behave.
(BTW - This may seem silly, but for safety why not install cheap wind gauges on the front of the cart?
Because if you can't tell whether or not you have safe flying speed without looking at a cheap wind gauge you shouldn't be flying anyway. But if it really floats your boat stick one on your glider and knock yourself out staring at it.
That way each pilot could determine when he should let go of the tubes based on the airflow over his wings.)
Each pilot who has half a fuckin' clue can do that without a gauge.
Tommy Thompson, Sr. - 2007/08/23 23:52:38 UTC
Whitewater

When a glider lifts from the dolly is controled by the upper tow point.

Image
Right.
- When you have an upper attachment on the keel at the trim point the glider comes off when it's supposed to.
- If you move the upper attachment too high/forward/fast you won't be able to push the glider into the air.
- But if you eliminate the upper attachment altogether (eliminate the trim force) you HAVE TO push out to get airborne.
Gerry Grossnegger - 2007/08/24 00:03:49 UTC
Winnipeg

You sure about the 3rd image? Done that, don't think I had to push out to lift, had to pull in during the tow.
What? 'Cause you didn't have the upper split of the tow force to trim the glider faster? Do ya think?
As to the 2nd one, gee, imagine the pilot actually having to fly the glider! It should fly him, right, no input required, it knows when it's flying and you have no idea, etc... Image
WHAT?
George Stebbins - 2007/08/24 01:31:00 UTC
Palmdale

At first glance this seems good, but... Do you really want some stick or other object out there where your tow bridle might catch it and haul the cart up non-symetrically?
But you're totally cool with a pro toad bridle that can and does haul the pilot/glider combo up lethally non-symmetrically. That plus a magic one-size-fits-all fishing line Pilot In Command which very clearly provides protection from excessive angles of attack for that form of towing.
Even for a second? I think I might refuse to tow on a cart like that.
But you're also totally cool with towing behind a Dragonfly controlled by some idiot total dickhead like Jim Keen-Intellect Rooney with an ability to fix whatever's going on back there by giving you the rope and is equipped with a tow mast breakaway protector to make goddam sure that you don't ever tow with a functional inappropriate weak link with a finished length of 1.5 inches or less.
I'd have to see it to decide.
Get fucked, George.
George Stebbins - 2007/08/24 01:33:52 UTC

The images are right.
Damn straight. Nothing the least bit wrong with them.
I think the wording just needs work.
Yeah. Change it to the polar opposite of what he's saying about trimmed two point and "pro-tow".
I suspect (but am not sure) that what Tommy means is that with the pro-tow, the pilot is pulled in.
The "pilot" is pulled THROUGH.
Then the PILOT must decide to leave the cart by raising the nose. If that's pushing out, ok, but really it is stoping pulling in. Just a wording issue, I think.
Yeah, right.
But I've pro-towed enough to know that you do make the decision yourself.
Nah, the glider couldn't POSSIBLY make the decision with no upper attachment and the Dragonfly approaching takeoff speed - or later when it climbs out. The glider's gonna stay glued to the cart - and the cart's gonna stay glued to the runway - no matter what.
The glider doesn't do it for you. Unless things are horribly wrong somehow... Image
Things couldn't POSSIBLY go wrong - horribly or to any other degree. You've got an appropriate weak link with a finished length of 1.5 inches or less to keep you from getting into too much trouble.
And Davis has pro-towed way more than almost all of us, I'd wager...
Fuck yeah! He's been at an around all this plenty long enough to understand what's what and who's who. So he should be the one setting us all straight and making all of our pilot and safety decisions for us.
Bill Jacques - 2007/08/24 02:20:03 UTC

1. Never Pro-Towed...
Better get with the program. You need to pro tow for the extra safety margin you'll need at all the comps Davis runs. Lose the wheels while you're at it - asshole.
- so I guess you could push out to raise and then stall out before the tug gains enough speed to allow you to control the glider (especially if the oncoming winds die down just as you lift off).
Bullshit. Start paying attention to the real life issues that kill people in AT.
2. I suggested the wind gauge because I learned via platform tow, and we never released until we saw the airspeed reached a certain level.
And you'd have been fuckin' DEAD just doing it by feel - INSTANTLY. Too slow and you hit the runway. Too fast and your lungs explode from the pressure drop.
Additional stuff on the cart does seem silly, and I always make sure my front wheel lift a little before I let go of the rope/hose...
That's not a reasonably good airspeed indicator?
- keep it simple, right?
Right. That's why pro toad bridles are so much safer than three pointers. And lose your reflex bridle and tip struts. You can get down a lot quicker when you really need to.
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Tad Eareckson
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Re: Departing the launch cart - Davis Show

Post by Tad Eareckson »

http://ozreport.com/forum/viewtopic.php?t=9230
Departing the launch cart
Gerry Grossnegger - 2007/08/24 02:36:51 UTC
George Stebbins - 2007/08/24 01:33:52 UTC

Then the PILOT must decide to leave the cart by raising the nose.
True enough. The pilot's pulled forward more with that brdle.
Oh really?

http://www.hanggliding.org/viewtopic.php?t=22233
Looking for pro-tow release
Zack C - 2011/06/16 03:14:35 UTC

I've never aerotowed pilot-only, but it is my understanding that this configuration pulls the pilot forward significantly, limiting the amount he can pull in further.
Davis Straub - 2011/06/16 05:11:44 UTC

Incorrect understanding.
That's not what Davis Dead-On Straub says.
That's probably why it says that.
It says that 'cause Tommy's an idiot and doesn't understand that a towline pulling the pilot forward has the precise opposite effect of the pilot pulling himself forward.
By the way (everyone), it's properly called a single-point tow bridle (the single point being the pilot, even though there's 2 straps).
Oh really?

http://www.hanggliding.org/viewtopic.php?t=26429
Pro Tow vs Three Point
Davis Straub - 2012/06/26 00:06:02 UTC

Why is pro-tow sometimes thought of as single point towing when it is clear to me that there are two points?
That's not what Davis Dead-On Straub says.
"Pro Tow" is a brand name that has been used by various companies.
"Pro Tow" is a snake oil term used to justify decertifying an aerotowed glider and thus violating FAA Exemption 4144.
That's like getting a nosebleed and frantically asking for a Kleenex. Sorry, don't have any, but we have lots of these tissues of other brands, just try not to die from blood loss while we go get that particular brand for you, though why you'd be so picky as to demand one brand versus another, when what you really want is just a tissue...
If that's pushing out, ok, but really it is stoping pulling in.
It's shifting your weight farther back than where it's being pulled by the tow force.
It's stuffing a bar that's already mostly stuffed as a consequence of dropping the thrust line way the fuck down from where it would be on a sane, properly trimmed...

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...configuration.
George Stebbins - 2007/08/24 03:46:54 UTC
Bill Jacques - 2007/08/24 02:20:03 UTC

...and I always make sure my front wheel lift a little before I let go of the rope/hose - keep it simple, right?
That's pretty much right. If the wheels come off the ground (other than "bouncing") then you are flying even with extra weight. Without the cart weight, it is even better.
Bullshit. The cart weight is fuckin' negligible.
Easy. Simple. Nothing to get caught in your tow bridle...
Yeah. That's only a problem...

http://www.hanggliding.org/viewtopic.php?t=14230
pro tow set-up
Jim Rooney - 2009/11/02 18:58:13 UTC

Oh it happens.
I have, all the guys I work with have.
(Our average is 1 in 1,000 tows)

Oh yeah... an other fun fact for ya... ya know when it's far more likely to happen? During a lockout. When we're doing lockout training, the odds go from 1 in 1,000 to over 50/50.
...when you're trying to free your Industry Standard bridle in a lockout emergency.
Just don't take it too high. Image
Yeah George. He probably never picked up on that in the course of his AT training and certification and subsequent experience.
Rob Clarkson - 2007/08/24 07:27:57 UTC
Dickhead.
Make sure you are going fast enough. Not too hard to do. When you lift the cart off the ground your going fast enough. When you drop it you will shoot up...
Bullshit.
...so pull in. Getting high on the tug when he's still on the ground is not cool.
Yeah. We killed close to a dozen of them that way last year. That's why Ridgely is having to fold.

But nobody should ever say anything to the tugs about getting high on the gliders...

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Tuggies can do no wrong. Besides, we glider muppets all understand that anything bad that can ever happen to us on tow is ENRIRELY...

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...*OUR* fault.
You can also tell your going fast enough when the tug leaves the ground.
Ya think?
Oh crap, but better than coming out too slow.
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Tad Eareckson
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Re: Departing the launch cart - Davis Show

Post by Tad Eareckson »

Tad Eareckson - 2016/02/22 19:42:18 UTC

Sure is a good thing you meet heads, experienced and well trained tug pilots, very experienced and very much in charge ground crew leaders had one of one of the least experienced pilots at the Worlds - who may not have understood the requests for him to hold onto the cart and came off slow and too early on a pro tow bridle, isn't it Davis?
No they didn't...

http://c2.staticflickr.com/2/1562/25190537495_d9a39e894f_o.jpg
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Two point Quallaby piece o' crap with the bicycle brake lever velcroed in the usual easily reachable place on the starboard downtube.

http://ozreport.com/11.167
2007 Worlds - nobody died
Davis Straub - 2007/08/23 14:58:11 UTC

You can leave safety up to the individual pilots or you can build safety into your system. There was only two minor accidents that resulted in injury to pilots during the 2007 Worlds. That is, if we ignore the pool party. Beer, vodka, Red Bull, and water - a dangerous combination.

We planned for two years for safety building on the record of the Flytec Championships held at Quest Air and the previous meets in Big Spring. There was an absolute requirement for certain types of bridles, weak links, and secondary releases.
The Quallaby Industry Standard garbage that everybody uses anyway and everybody and his fuckin' dog knows fails all the time and is totally useless...

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http://ozreport.com/pub/images/fingerlakesaccident3.jpg
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...in anything and everything remotely resembling an emergency situation. Keep planning and building on those records, Davis. It boggles our minds to imagine the advancements we'll be seeing in the course of next quarter century.
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Re: Departing the launch cart - Davis Show

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Jump to next post:
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Departing the launch cart
Detective Shaft - 2007/08/24 11:17:21 UTC
Chattanooga

Where's Your Checklist?
In my head - asshole. I don't need a goddam piece of paper to look over before commencing an AT dolly launch.
Not attatching one self to the dolly will generate a few whacks on the;
- head
- base tube wheels
- base tube
- helmet
Definitely. If you haven't got the hold-downs disaster is inevitable.
If you survive a few of these whacks you'll eventually come to your senses and develop a checklist.
Bullshit. There's NOBODY who ever whacks more than once blowing a dolly launch.
Maybe someday you'll remember to prepare for launch using a checklist?
Maybe I will. And maybe there's a reason that paper launch checklists are totally nonexistent at all major AT operations.
Jim Rooney - 2007/08/24 11:48:03 UTC

I'm going to back up a bit and describe a good way to leave the cart, then why some other ways that have been suggested might not be as good as they seem at first...
Oh good. If we're lucky maybe we can get twenty pages out of you on the finer points of dolly launching. Stuff that all of our instructors were all too stupid to be able to get through to us muppets and all we muppets were too stupid to figure out ourselves.
What I'm looking for when exiting the cart is what I call "sliding out of the cart".
How lucky we are to have you to establish aerotowing terminology for us.
It's flying out of the cart, but without doing anything. This is determined by various adjustments, but that to me is the ideal exit... slipping into the air.
So we're in agreement that Alejandro's left a bit to be desired.
First off is the pilot.
You mean...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3600
Weak link question
Jim Rooney - 2008/11/24 05:18:15 UTC

Well, I'm assuming there was some guff about the tug pilot's right of refusal?
Gee, didn't think we'd have to delve into "pilot in command"... I figured that one's pretty well understood in a flying community.

It's quite simple.
The tug is a certified aircraft... the glider is an unpowered ultralight vehicle. The tug pilot is the pilot in command. You are a passenger. You have the same rights and responsibilities as a skydiver.
It's a bitter pill I'm sure, but there you have it.

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.
...the guy on the Dragonfly?
What you should need to do is focus on moving the cart and glider as one.
Would that be the Zen AT dolly launch approach?
That's what those handles are about. Sure, they keep you from bouncing out of the cart too, but their other function is to allow you to keep the cart moving with you.
And here I was thinking that they were just there for decoration and orange because that's everybody's favorite color.
Put simply... you want to maintain bar position.
Don't push out.
Don't pull in.
Don't let the tug pull you through the control frame (this is the same as you pulling in).
Both before and after the wing starts flying, right?
Next up is your AOA.
Modern carts have adjustable tail heights.
Really? You make adjustments in AT launch equipment to handle differences in individual gliders?

http://ozreport.com/forum/viewtopic.php?t=31052
Poll on weaklinks
Jim Rooney - 2013/03/04 19:31:36 UTC

We all play by the same rules, or we don't play.
Morningside decided that they were happy with 200lb weaklink. They changed their tug's link and they don't just pass the stuff out either. If you'd like to know more about it... go ask them.
The law of the land at comps was 130lb greenspot or you don't tow. Seriously. It was announced before the comp that this would be the policy. Some guys went and made their case to the safety committee and were shut down. So yeah, sorry... suck it up.
Sounds awfully complicated to me. Wouldn't it be a lot simpler, safer, fairer to establish a law of the land and have everybody play by the same rules or not play at all?
This was brought into being due to crosswinds...
Right A long time ago in a galaxy far, far away there was a standard keel support that was a good rule of thumb for all 260 pound gliders. This worked well for many years until crosswinds were discovered.
...some gliders (WW in particular) sit at a much higher AOA on the cart, needing to rotate further to get to a flying AOA. This shows up most in crosswinds as it's easier to have a low speed exit resulting in a dropped wing with bad results.
As opposed to a dropped wing with improved results.
This is (at least partially) where the theory of holding the cart till you lift it off the ground comes from (more on this later).
It's just a THEORY though - like evolution, global warming, a Rooney Link decrease in the safety of the towing operation when a glider's climbing hard in a near stall situation. So just go with whatever you feel like on a crosswind AT launch.
Now that we can set the AOA on the cart...
Wow. I wonder who the fucking genius who worked that out was. Bobby Bailey?
...you shouldn't have to deal as much with it as you roll.
Your wingtips should be nearly level with the ground, erring on the tip high AOA. Talk to someone that does ground crewing for more info.
Like the very experienced and very much in charge ground crew leaders who did such a great job of getting Alejandro safely airborne twelve days ago?
Last we come to glider trim.
If your glider isn't trimed well for towing (keel point tow off...
By keel point "off" do you mean a bit fore or aft of the trime point? Or completely off...

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...the way your cool pro toad buddy preferred to have it?
...vg set wrong) it will have the effect of wanting to pull you through the bar...
Yeah. No matter which way you go from the optimal trime and VG settings the consequence will be getting pulled through the bar more.
...same thing as the tug.
Please just shut the fuck up and go back to paraglider tandem thrill rides in New Zealand.
So
With everything set right, you should just slide happily out of the cart.
You shouldn't need to push out of the cart and you shouldn't need to lift the cart.

Next up... bad things and why they're bad
Homemade equipment, straight pin barrel releases, Tad-O-Links, and what else?
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.
Which is why it's called THREE point towing. 'Cause the energy - or PRESSURE - is split evenly in half between you and the glider. Asshole.
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.
Exactly. So if you do nothing with all the tension going to the pilot and nothing on the keel to trim the glider faster you'll be pulled into the ground 'cause of all the weight way the hell forward under the nose.
All result in leaving the cart at too high a speed.
Damn straight.

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Pro Toad Steve Blenkinsop here should be pushing out to get that excessive speed of his under some kind of reasonable control. If he keeps going like that it's pretty much guaranteed that he's gonna slam into the propwash. That'll make the glider harder to control and might not help to break his weak link enough. And then he might tear his wings off or lock out. And even if he doesn't he'll still be on tow - which is infinitely more dangerous than being off tow, regardless of what the assholes who make the crappy argument to the contrary might say.
Why is this bad? I thought speed was good?
Isn't the glider, as long as it's reasonably well lined up and level, going to be going exactly the same speed as the tug, which hasn't left the ground yet, no matter what? Have we ever, in the entire history of aerotowing, had an account of a glider being able to put slack in a towline before getting up to a substantial altitude? And can we find a video of even that happening? You'd hafta climb way the fuck above the tug and instantly stuff the crap outta the bar. You wouldn't be able to do it pro toad and I doubt you could do it two point. The tug would just accelerate and climb.
Too much of anything is bad.
Except, of course, for...
Jim Rooney - 2013/03/05 21:40:02 UTC

You want to break off the towline? Push out... push out hard... it will break.
As others have pointed out, they've used this fact intentionally to get off tow. It works.

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.

I'm sorry that you don't like that the tug pilot has the last word... but tough titties.
Don't like it?
Don't ask me to tow you.

Go troll somewhere else buddy.
I'm over this.
...weak link effectiveness. You never have them TOO safe.
You pretty much guarantee that you will slam into the propwash.
Damn straight. Last year in Florida alone there were six muppets who were killed when they slammed into propwash. Two others had their wings torn off but were medevaced out in time to keep what was left of them alive.
Not only does this make the glider harder to control (you're now swiming in the rapids instead of a calm lake)...
Damn straight. Just look at the videos:

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Definitely not for the faint of heart.
...it tends to help break weaklinks.
So?

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Jim Rooney - 2011/08/26 02:44:10 UTC

The "purpose" of a weaklink is to increase the safety of the towing operation. PERIOD.
You're saying that it helps to increase the safety of the towing operation. PERIOD. If weak links aren't working then how can they possibly be fulfilling their purpose - which no one but a total moron would want to interfere with? It's like the airbags in my car. Every once in a while I drive into a telephone pole at thirty miles an hour so they can do their job and make my drive safer.
Bart Weghorst - 2011/08/28 20:29:27 UTC

Now I don't give a shit about breaking strength anymore. I really don't care what the numbers are. I just want my weaklink to break every once in a while.
Wouldn't that be a good opportunity for u$hPa's 2015 Hang Gliding Instructor of the Year award recipient to get what he wants from the focal point of our safe towing system?
This is normal everyday highspeed cart exit.
Oh. So it's normal everyday stuff and terribly dangerous but somehow we never seem to hear about all the crashes and near misses, see the videos, read the there-I-was-thought-I-was-gonna-die accounts on the Jack and Davis Shows and none of these highly professional and safety conscious AT operations around the county seem to be able to get us muppets on the right track.
Taking things a bit further...
Fuck no. That was way too scary already.
Take the "I shouldn't need to do anything on tow" mentality (UHG!)...
Yeah?
You are a passenger. You have the same rights and responsibilities as a skydiver.
And here I was thinking I was just a passenger, with the same rights and responsibilities as a skydiver - but without the Coke and peanuts I get on a regular commercial flight.
...and mix it with transitioning to pro towing.
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This gets really interesting really fast.
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Way too interesting for my tastes, thanks. And I hear Ben Dunn hasn't been much of a fan lately either.
Bad habit #1, not flying the glider... just letting the tug drag you around by the nose...
I don't tie anything to my nose - dickhead.
...combines with the fact that pro towing REQUIRES the pilot to do something (not let that bar move).
So you want us to have BOTH hands...

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...on the basetube? Or are we OK with just one for the nanosecond it takes to pry our Industry Standard easily reachable bent pin releases open with the other?
So instead of holding the bar where it is, bad habit pilot just lets the tug pull him.
Yeah. This happens in real life. Pro toads just take a nap and go up in thermal conditions to a couple thousand feet - never getting any feedback from the air or the highly professional staff a couple hours later when they land.
This pulls him through the control frame with the same effect as the pilot pulling in... a LOT.
Fuckin' lying stupid piece o' shit.

http://www.hanggliding.org/viewtopic.php?t=27217
Bad Launch!
Ryan Voight - 2012/09/26 14:23:55 UTC

Running to the right = weight shift to the right.

It's all about what the glider feels. Running to the right pulls the hang loop to the right, just like when you weight shift at 3,000 ft. Glider doesn't know or care what means you used to pull the hang loop to the right.
Birds of a feather.
I've seen gliders go negative while still on the cart this way.
Like?:

Image
http://ozreport.com/pub/images/fingerlakesaccident2.jpg
http://ozreport.com/pub/images/fingerlakesaccident3.jpg
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The results are never pretty.
And here I was thinking your dear friend Davis Dead-On Straub had been at an around all this plenty long enough to understand what's what and who's who.
Ok, on to a less dramatic (and much more prevalent) problem...
Taking the cart with you, then dropping it.
Yeah. These are all prevalent problems - that none of the AT pros doing the instruction and running the operations are ever able to put the slightest dent in.
This comes from 582s vs 914s and crosswind launching with bad AOAs.
That would certainly explain John Claytor. By the way... Which one of you dickheads was driving the tug on that one?
582s take longer to get you to flying speed.
And here I was thinking...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3661
Flying the 914 Dragonfly
Jim Rooney - 2008/12/06 20:01:49 UTC

You will only ever need full throttle for the first fifty feet of a tandem tow. Don't ever pull a solo at full throttle... they will not be able to climb with you. You can tow them at 28 mph and you'll still leave them in the dust... they just won't be able to climb with you... weaklinks will go left and right.
...that the Rooney Link was the limiting factor on how fast a tug could accelerate and hold onto its passenger module.
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.
What a marvelous hang gliding historian you are.

http://ozreport.com/forum/viewtopic.php?t=30971
Zach Marzec
Jim Rooney - 2013/02/13 19:09:33 UTC

It was already worked out by the time I arrived.
Are there no limits to your knowledge and expertise?
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.
My, what incredibly insightful and creative individuals we are. A keel support which adjusts to trim gliders with different control frame heights. Who'da thunk.
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.
Gawd. If only other AT instructors were capable of following your leads.
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.
Dramatically! To a HUGE percentage of your six G positive certified glider's capacity.
Behind a 582, you're not accelerating nearly as fast as a 914.
And if you're using a Rooney Link pitch and lockout protector on a grass strip you might not be accelerating at all if your launch assistant is a little slow in getting you moving - no matter what's on the other end of the string.
Things happen faster.
Up to Mach 5. Maybe more. Who knows?
Holding on a second too long now has dramatic results.
Suck my dick.
You wind up slaming into the propwash at the same time you're radically altering your wingloading (dropping a 100lbs).
Right. Fifty pounds per hand on orange hold-down.
I can't count the number of weaklinks I've seen break due to this alone.
And not at all to the fact that you total douchebags think that the standard aerotow weak link is good for 520 pounds of towline pressure.
It's not a horrible problem, but it just makes me shake my head.
http://www.brooklyndaily.com/stories/2015/14/all-nfn-gliding-2015-04-03-bd_2015_14.html
Jo shakes her head at tween hang-gliding - Brooklyn Daily
Joanna DelBuono - 2015/04/01

Lunacy rears its ugly head again. Several days ago a 12 year old was killed in a hang-gliding accident in Nevada when the boy and the instructor crashed into a dry lake bed.

What is wrong with parents to day? And where has all the common sense gone?

In these United States you have to be 21 to drink, 18 to vote and in most states 16 to drive. So how come there is no restriction on hang gliding? Or shooting an automatic weapon on a range in Arizona for that matter.

Why hasn't the FAA enacted an age restriction on all types of aviation practices?

I don't care how safe an instructor says it is. There is no way on this green earth that I would allow my 12 year old child to step into a glider and soar into the wild blue yonder with anyone. I don't care how experienced, or what the guarantee. No one is taking my child on such an adventure.

Not for all the "Please, mommy, pleases," in the world.

"Hang gliding was this year's adventure" reported KMVT.com. "The 12-year-old wanted to be first," said a relative. Who cares if he wanted to be first? If it isn't safe you just say "no." That's why we are the adults and they are the children - we know better.

The accident occurred when the team in the truck made a sharp turn while the glider was still attached and the glider came crashing down.

According to the story in the NY Daily News: "The boy's family had hired the man to take him hang gliding near Jean, Nevada." They hired him? SMH.

Not for Nuthin™, but what is wrong with parents today? Why do parents feel they have to allow their children to make these decisions, and why do they feel the more dangerous the activity, the more fun it is? What the heck ever happened to visiting a museum, the beach, or a famed landmark for a good, old-fashioned, fun-filled, family vacation adventure?
You got this douchebag's phone number?

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http://www.kitestrings.org/post9062.html#p9062
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Re: Departing the launch cart - Davis Show

Post by Tad Eareckson »

Had a bit of a lightbulb moment regarding the physics/dynamics of hang glider aerotowing working on the previous post.

When we're being pulled up by a tug we want the thrust line running through our center of mass / center of drag (close to synonymous for the purpose of the exercise)...

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...just as the assholes on the other ends of the strings...

http://www.zenadsl2877.zen.co.uk/mf-aerotow/8-GermanDF-AWier.jpg
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...are configured.

When we're rolling on the cart our jettisonable takeoff gear is generating a lot of drag through rolling resistance and inertial opposition as we're accelerating (which we always are when we're on the cart).

So we're lowering the center of drag pretty substantially and hooking up pilot-only ain't a bad alignment...

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The moment we kiss that crap bye-bye however...

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Another way of expressing that... While a:
- one pointer is rolling the cart's pulling back on the bottom of the glider and trimming the nose down
- two pointer is flying the upper bridle attachment is pulling forward on the top of the glider and trimming the nose down
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Re: Departing the launch cart - Davis Show

Post by Tad Eareckson »

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

So we have:
Gerry Grossnegger - 2007/08/24 02:36:51 UTC

By the way (everyone), it's properly called a single-point tow bridle (the single point being the pilot, even though there's 2 straps).
And then seven posts later:
Jim Rooney - 2007/08/24 12:20:06 UTC

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.
Doesn't "CORRECT" and "EDUCATE" Gerry in his campaign to get all the key players on the same page and the sport on the right track. Just ignores him and refers to two point as three - with the inescapable implication that pro-tow is a synonym for two point.

Also note that if one were just delusional one would NEVER discuss the idiosyncrasies of three point and pro-tow. One would flip between three and two point. Just as one would never discuss Hang Twos versus Beginners. There's a telltale awkwardness here that betrays a deliberate, calculated intent.

And also note while these motherfuckers will ALWAYS refer to two point as three they will NEVER refer to pilot-only as two point because they understand how blindingly stupid it would sound and make them look.
Tad Eareckson - 2011/04/06 23:12:31 UTC

I DESPISE the term "pro tow".
And, of course, the assholes who use the terms "pro tow" and "three point". I get overpowering urges to beat faces to bloody pulps.
Mike Lake - 2012/10/22 22:29:26 UTC

For the first twenty years the terms used for the two flavours of towing caused little or no confusion.
EX fuckin' ZACTLY! Find me some crap that flows from the pens of these motherfuckers that isn't engineered to confuse and obfuscate. They can only thrive in this sport...
Mike Lake - 2012/06/09 00:25:14 UTC

Cone of safety, flying with a fin is better for your weak-link, too many other examples from the last few pages.
What a load of shit.
Who are these people?
...in a climate of confusion and obfuscation. And how better to maximize their margins than to corrupt the language and...

http://www.hanggliding.org/viewtopic.php?t=22233
Looking for pro-tow release
Zack C - 2011/06/16 03:14:35 UTC

I've never aerotowed pilot-only, but it is my understanding that this configuration pulls the pilot forward significantly, limiting the amount he can pull in further.
Davis Straub - 2011/06/16 05:11:44 UTC

Incorrect understanding.
...science? 1984 and Newspeak.

A one point bridle would be a dangerous compromise - possibly a contributing factor...

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...in a fatal crash preceded by a standard aerotow weak link inconvenience.

A pro tow bridle...

http://www.hanggliding.org/viewtopic.php?t=22233
Looking for pro-tow release
Davis Straub - 2011/06/16 12:31:33 UTC

Well, that may be his opinion, but it is nothing more than that. Protow requires more experience and skill and you certainly wouldn't use it as the first method for a new aerotow pilots, but is not less safe (nothing in hang gliding is safe) than the two point method.
...is every millimeter as safe as a three pointer - as long as one has been at an around all this plenty long enough to understand what's what and who's who - and is what all the cool kids use. Like the way only muppets land in Happy Acres putting greens. REAL pilots always land in narrow dry riverbeds with large rocks strewn all over the place AT LEAST as safely than the muppets on the putting greens - usually much more so.
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Re: Departing the launch cart - Davis Show

Post by Tad Eareckson »

http://ozreport.com/forum/viewtopic.php?t=9230
Departing the launch cart
Bill Jacques - 2007/08/24 13:00:55 UTC

Well, that answers my bewilderment why the glider eased out so easy the two times I forgot to grab the rope/hose(s)!
'Cause when you move a wing through the air really fast it goes up?
Okay, but I like to lift the wheels up only and inch or two.. especially when I have a varying headwind. That gives me reassurance the wings are really working. That's okay, I assume?
- I dunno... Let's ask Jim Keen-Intellect Rooney.

- And the sound and feel of the wind and your wing doesn't?

- Just as long as the extra cart time doesn't have you separating just as you're hitting the deadly 914 propwash that's claimed so many of the lives of our brothers over the years.
Two other question areas:
- What's the best way to use my Rooney Link as an instant hands free release when I'm swiming in the rapids of the propwash in the unlikely event it doesn't break when it's supposed to?

- I hear there's also a way to swing my body way outside the control frame so it stays up there while I reach out with one hand and release. Can you give me a link to a video so's I can see exactly how it's done?
1. Immediately after I lift off, I adjust to about 6 - 10 ft off the ground and wait for the tug. And I hold it there until you lift up. Then I follow the tug (wing to wheel level) up, right?
Exactly. If you get up this high:

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above the tug you're very likely to nose him in and kill him. Fortunately we have a standard aerotow weak link...

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...which senses the danger of which the tug pilot is totally unaware and automatically...

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...increases the safety of the towing operation.
2. Also, is single point tow ("pro tow")...
Oh. A single point tow is the same thing as a pro tow?
Jim Rooney - 2007/08/24 12:20:06 UTC

In three point towing, 1/2 the energy is transmitted to the glider, 1/2 to you. In pro towing, you're it.
So a Jim Keen-Intellect Rooney three minus a Jim Keen-Intellect Rooney one equals a Gerry Grossnegger / Bill Jacques one?
So why are you talking to this dickhead who thinks that one plus one equals three?
...much harder than keel/harness tow?
- Notice Bill terms it a "keel/harness tow" rather than a three point. He understands that one plus one equals two but won't refer to it as a two point tow 'cause he doesn't wanna contradict Jim Keen-Intellect Rooney and risk...

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Jim Rooney - 2011/08/31 09:25:57 UTC

Oh how many times I have to hear this stuff.
I've had these exact same arguments for years and years and years.
Nothing about them changes except the new faces spouting them.

It's the same as arguing with the rookie suffering from intermediate syndrome.
They've already made up their mind and only hear that which supports their opinion.

Only later, when we're visiting them in the hospital can they begin to hear what we've told them all along.

Nobody's talking about 130lb weaklinks? (oh please)
Many reasons.
Couple of 'em for ya... they're manufactured, cheap and identifiable.

See, you don't get to hook up to my plane with whatever you please. Not only am I on the other end of that rope... and you have zero say in my safety margins... I have no desire what so ever to have a pilot smashing himself into the earth on my watch. So yeah, if you show up with some non-standard gear, I won't be towing you. Love it or leave it. I don't care.
http://ozreport.com/forum/viewtopic.php?t=30971
Zach Marzec
Jim Rooney - 2013/02/17 10:37:47 UTC

I'm not sure who you're arguing with Zack, but it's sure not me... cuz man... you've got some pretty big hangups mate.

Ra ra ra... burn the greenspot!!!!
Get real man.
You think that's all we use?
Hell, just in this thread, you seem to have missed the 200lb orange links.
Ah, but your strawman argument lives and breaths by your black and white hyperbole.
When you come back to reality, let me know.
Till then, I'm sick of it.

You're hear to argue. Plain and simple. I've got better stuff to do.
Go blow smoke somewhere else. I couldn't give a rats ass... I won't be towing you so what do I care?
...getting on his shit list and being blacklisted by the AT industry at large.

- Well yeah, it's...

http://www.hanggliding.org/viewtopic.php?t=22233
Looking for pro-tow release
Davis Straub - 2011/06/16 12:31:33 UTC

Well, that may be his opinion, but it is nothing more than that. Protow requires more experience and skill and you certainly wouldn't use it as the first method for a new aerotow pilots...
...HARDER. But, after you've acquired the requisite experience and skill, it's...
...but is not less safe (nothing in hang gliding is safe) than the two point method.
...every bit as SAFE.

http://4.bp.blogspot.com/-bRrpHNa68iY/UQ6Pv9gRZyI/AAAAAAAAjTg/Hc22bx5122Q/s2048/20943781_BG1.jpg
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It's like wheels. You certainly wouldn't have new pilots flying without wheels but after they've gotten the experience and skill needed to perfect their flare timing...

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.
...there's absolutely no downside to leaving them at home in the closet.

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When should a pilot switch over to that?
- Whenever he feels like becoming one of the cool kids.

http://2.bp.blogspot.com/-9Ek9_lFeSII/UZ4KuB0MUSI/AAAAAAAAGyU/eWfhGo4QeqY/s1024/GOPR5278.JPG
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http://2.bp.blogspot.com/-Xh_NfnOcUns/UZ4Lm0HvXnI/AAAAAAAAGyk/0PlgrHfc__M/s1024/GOPR5279.JPG

- Oh. It's a SHOULD thing. It's something you naturally and inevitably graduate to as your pilot experience accumulates and skill increases. After you're about a 3.5 aerotower you wouldn't wanna be caught dead flying two point.

http://www.hanggliding.org/viewtopic.php?t=29884
Hat Creek Power Whack
Mike Bilyk - 2013/09/07 17:07:26 UTC

Wheel landings are for girls!
Unless you're a fuckin' girl or fag or sumpin'.

- Whenever he feels comfortable towing with the bar so far back that it's nearly...

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...or totally...

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...stuffed just coming off the cart and well before the tug has even gotten airborne.

- After he's considered all worst case scenarios...

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...and concluded that he'll never benefit significantly from having the thrust line running through his center of drag whenever any shit hits the fan such that the glider's flying in the configuration for which it was certified - in accordance with the terms of FAA Exemption 4144 under which aerotowing hang gliders is legal.

Image
What are the advantages/disadvantages to single point?
Advantages? Since the fuckin' glider manufacturers refuse to build quality AT releases into their gliders you don't hafta fly around for the two or three hours after the release with a bunch of draggy crap in the airflow.

Disadvantages? Once you've acquired the requisite experience and skill there's nothing really worth mentioning - 'specially if you use a really safe weak link which will very clearly provide protection from excessive angles of attack, high bank turns and the like for that form of towing.
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Re: Departing the launch cart - Davis Show

Post by Tad Eareckson »

http://ozreport.com/9.074
It was Ricky Duncan
Davis Straub - 2005/04/05

He flew the glider and waited to get high enough to get the dolly released.
Ricky Duncan

I noticed the dolly video clip sent in by Billo.
http://www.youtube.com/watch?v=QLuYBZMT0GE
He neglected to mention that it was me.

As you can see the glider was rolling hard to the left. There was about a dozen cars that I was heading straight towards but managed to get the glider back on line. I was fortunate only received mild back strain from having to high side and push out to allow a bit of altitude to remove the dolly. I guess after doing so much aero towing over the years (since 1983) I had become a bit complacent. It was a good cheap wake up call!

I like the concept you mention about handles rather than rope. We will probably change our dollies to incorporate handles.
The handles are shown here:

Image

The handles consist of 1 foot lengths of 3/8" pneumatic hose, air hose, shoved through a 5/8" hole drilled through the wooden cradle. An 11/16" machine bolt a little longer than the thickness of the cradle with a flat washer is screwed into the hose to hold it in place. I haven't been able to pull out the hose. You can see (if you look hard) that the hose is placed about five or six inches directly below the slot in the cradle for the base tube.

In the cart you hold onto your base tube and the air hose. Your grip is a bit wider than perhaps you would normally use if you had a rope under the bar all the way across.

When I went to Wallaby Ranch today to fly the Wills Wing Attack Falcon, Malcolm Jones was nice enough to tie down the rope on one side on my cart to shorten it. Otherwise it could easily have gone over my speed bar and I could have very easily taken the cart with me. I would have been able to get rid of the cart, but it would have easily hung on until I made a strenuous effort to get rid of it.

The ropes on these carts (and previously on the carts at Quest Air) are long enough to allow pilots with big plastic wheels to hold onto the ropes. That makes them too long and dangerous to pilots who don't have such wheels. I got to experience really tight ropes on carts at the Worlds in Oz where I had to stretch my fingers just to get their tips onto the rope. No one was flying with big plastic wheels there.

As I recall the ropes at Cloud 9 where quite a bit tighter than the ones I saw here at Quest Air and still see at Wallaby Ranch.
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- 00 - seconds
- 00 - frame (24 fps)

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Release.

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Cart is dumped a fraction of a second after this frame.

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Dangerous turn under two hundred feet.

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Re: Departing the launch cart - Davis Show

Post by Tad Eareckson »

http://ozreport.com/8.163
Flying with the dollie
Davis Straub - 2004/08/06
Big Spring

Flying with the dollie
It's a DOLLY - you moron.
Greg DeWolf captures Pete Lehmann taking the cart with him.
Just keep calling it a cart. Harder to fuck up.
A few days ago Pete Lehmann took off with one of the carts here at the US Nationals. Greg DeWolf has been capturing people's launches and landings for a video project and he happened to capture the whole sequence of Pete's launch.
Everybody's launching on wheels. How are they landing?
Image

A reconstruction of what happened has indicated that Pete's bridle was routed over the forward horizontal bar of the cart and under the next horizontal bar.
http://ozreport.com/11.167
2007 Worlds - nobody died
Davis Straub - 2007/08/23 14:58:11 UTC

It wasn't an accident (Big Spring, Texas)

You can leave safety up to the individual pilots or you can build safety into your system. There was only two minor accidents that resulted in injury to pilots during the 2007 Worlds. That is, if we ignore the pool party. Beer, vodka, Red Bull, and water - a dangerous combination.

We planned for two years for safety building on the record of the Flytec Championships held at Quest Air and the previous meets in Big Spring. There was an absolute requirement for certain types of bridles, weak links, and secondary releases. The tug pilots were experienced and well trained. The ground crew leaders were very experienced and very much in charge.
Guess they were pretty busy enforcing the absolute requirement for certain types of bridles, weak links, and secondary releases.
When Pete got enough speed to start flying he took the cart with him.
So why didn't he just abort the tow? Did he need...

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...BOTH hands to fly the glider?

How 'bout his experienced and well trained tug pilot? I was under the impression that those guys could fix whatever was going on back there by giving the glider the rope.
The bridle pulling down on the front bar and up on the bar behind was able to keep the back of the cart from rotating down.
Bill Bryden - 1999/06

Rob Richardson, a dedicated instructor, died in an aerotowing accident February 27, 1999 at his flight park in Arizona. He was conducting an instructional tandem aerotow flight and was in the process of launching from a ground launch vehicle when the accident occurred.

Rob had started to launch once but a premature tow line release terminated this effort after only a few meters into the launch roll-out. It is suspected the cart was rolled backwards a bit and the tow line was reattached to begin the launch process again. During the tug's roll-out for the second launch attempt, the tug pilot observed the glider clear the runway dust and then begin a left bank with no immediate correction. At that point he noticed that the launch cart was hanging below the glider and immediately released his end of the 240 ft. tow line. The tug never left the ground and tug pilot watched the glider continue a hard bank to the left achieving an altitude of approximately 25 feet. Impact was on the left wing and then the nose of the glider. Rob was killed immediately from severe neck and head trauma. Rob's body likely cushioned much of the student's impact. She was basically uninjured but suffered short term memory loss (not uncommon in hard crashes) and did not recall the events of the accident.

Of particular note is that the launch cart was not observed dangling from the glider. Rather it was seen positioned below the glider exactly as when the glider is resting upon the cart when on the ground. The cart construction was a rather typical triangle type arrangement. Approximately midway between the rear wheel and two front wheels, a cross member was connected between the two main frame rails running fore and aft. This cross member was parallel to the glider's control bar and located at about the pilot's waist when the pilot is positioned ready to launch. The tug pilot noted after the incident that the tow line was routed under this frame member on the cart and then connected to the release.

It is speculated, that after the aborted first launch, the bridle fell below this frame member and when it was picked up to reattached the tow line, it was pulled up but inadvertently was looped under the cross member. This would be consistent with the tug pilot's observations of the tow line after the crash and would explain how the cart could be held beneath the glider with the glider still positioned in the control bar and keel cradle points while airborne.
At about thirty feet...
Oh. They got up to thirty feet. Pete hadn't done anything on his end and the experienced and well trained tug pilot (whom you're conspicuously not identifying) - who was still on the ground when Pete lifted off with the cart - had just continued to accelerate and climb out normally. So was Pete planning on going on task with this thing?
...the weaklink broke under the strain of keeping the cart from rotating.
- Which was essentially the same strain at the front end of the towline, right?

- So under what strain did THIS:

http://www.chgpa.org/forums/viewtopic.php?f=2&t=4931
Zapata
Pete Lehmann - 2011/06/24

Blood on the Tracks

BJ Herring's intention was to attempt a gigantic world-record distance triangle of 260 miles, Mike Barber needed to test fly his new glider locally, while the Brazilians too wanted to do some gear-sorting and experience the tow operation. In the end, the soft lift and constant cross wind resulted in BJ's triangle being truncated into an outnback to Laredo (circa 80 miles), Mike's test flight proved his glider's pitch to be badly out of trim, something that may have contributed to his belly-flop landing on the runway, and the Brazilians had a bunch of broken weak links, part of an unusual number that have been experienced here.

And then there's my weak link break. I had been looking forward to attempting an unusual eighty mile flight to the south east along the Mexican border towards McAllen. But the instant I came off the cart my weak link broke. That shouldn't have been a problem as I had good speed to transition to a landing. However, I had zipped up my harness a bit too far and couldn't unzip it in the seconds available to me.

Still in my harness, I opted to belly land on the runway. Unfortunately the repaved runway has an extraordinarily coarse texture, that of a heavy grit sand paper, which resulted in my harness and knee being shredded. The harness can be fixed with Shoe Goo, but the knee required three stitches to pull together the resulting mess. The doctor who treated me at the clinic was sufficiently impressed by it to take some pictures for his colleagues. I was extraordinarily lucky, and can walk well and should be flying in a couple of days.

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weak link of Pete's break to increase the safety of the towing operation?
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The cart flew through the air making a perfect three point landing...
What? It didn't whipstall itself to a dead stop to maintain the skill it needs to land in narrow dry riverbeds with large rocks strewn all over the place?
...and was ready for the next pilot.
Did the next pilot's very experienced and very much in charge ground crew leader find time to make sure his bridle was routed straight to the tug - in addition to enforcing the absolute requirement for certain types of bridles, weak links, and secondary releases?
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Pete did a good job flying the glider...
With both hands...

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...on the basetube at all times, right?
...and not worrying about the cart.
Or anything or anyone it might have fallen on when the focal point of his safe towing system decided to increase the safety of the towing operation. Yeah, Pete did a really great job. Much better than all the pilots there that day who DIDN'T take their launch dollies flying with them.
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Tad Eareckson
Posts: 9150
Joined: 2010/11/25 03:48:55 UTC

Re: Departing the launch cart - Davis Show

Post by Tad Eareckson »

http://ozreport.com/forum/viewtopic.php?t=9230
Departing the launch cart
Jim Rooney - 2007/08/24 12:20:06 UTC

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).
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What an off-the-scale incredible asshole.
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