2016/04/03 Tres Pinos fatality

General discussion about the sport of hang gliding
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<BS>
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Re: 2016/04/03 Tres Pinos fatality

Post by <BS> »

But still can't be named. I think we're forging ahead on the all time world record of information suppression on this one. Day 5 now and we still don't even have a name.
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Steve Davy
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Re: 2016/04/03 Tres Pinos fatality

Post by Steve Davy »

http://www.wingsofrogallo.org/board/viewtopic.php?f=6&t=2009
April 19th Meeting Cancelled
Chris Valley - 2016/04/19 20:46 UTC

Received an email that tonight's meeting is cancelled - so posting here to let folks know.
Good idea. Don't want a bunch of folks getting together and asking questions about what the fuck happened three Sundays ago.
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Tad Eareckson
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Re: 2016/04/03 Tres Pinos fatality

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=34277
"evidence of that silliness"
Ryan Voight - 2016/04/19 05:36:02 UTC

With the center of mass moved laterally from center, you could look at it as- splitting the wing down the middle- one wing has more mass than the other... or you could look at it as the center of mass is the central point, and so the distance from CM to wingtip is longer on one side than the other... and therefore drag is greater on one side than the other.
Shove it, Ryan.

- The wings have identical MASS - and WEIGHT.

- The central point - however you're gonna try to define what the hell that is - is always gonna be defined by a plane defined by the centerline of the sail and the midpoint of the control bar with the glider balanced and symmetrical.

- The center of mass changes every time the pilot does something.

But yes... When the pilot DOES something with respect to roll the distances from the center of mass to the wingtips become unequal. Try staying with that and we might get somewhere.
Entirely exaggerated, shifting the aircraft's center of mass to the right, the right wing is the bowling ball, the left wing the feather.
1. Which is like saying that a rope lifting a bowling ball weighs more than a rope lifting a feather.

2 If the "pilot" shifts his mass to the right of the runway by running the wings remain equally loaded and symmetrical and react to the new vector by rolling left.

3. If the PILOT (without the quotes) pulls himself towards the right downtube / the right downtube towards him he'll more heavily load the right wing and the glider will roll right.
We don't fly in a vacuum lol
Try it sometime.
And to Brian Scharp, I'm very glad you are thinking about how to correct a lifted wing on launch...
You also are thinking about how to correct a lifted wing on launch. It's just that you don't have the wiring to process the physics. And/Or you're doing backflips to try to salvage your credibility after painting yourself into multiple corners with your prior creative truthfulness.
...but I was under the impression this thread was about why weight shift makes a hang glider roll, spurred by Jono's "I'm the center of everything and I roll the glider around me" theory.
He's not and didn't say so. The center of everything is between the pilot and the wing and considerably closer to the pilot.
Yes, that came up while discussing "pull against the lifting wing", to which I elaborated in the other thread that is a CUE, and I think you are taking it a bit too literally... If you're running and the glider is lifting up on your harness, your harness is pulling down on the glider...
Yes. And if you're running without a harness or...

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...without your harness being connected to your glider the glider will lift up on your hands and your hands will pull down on the glider. And you can use your hands to torque the bar/glider around your center of mass to turn or correct turns. And you can get fully airborne and fly for a little bit...
Mark Johnson - 2008/08/31

Randy and Kunio were both ready to launch at the same time. Randy stepped up first and was talking to the guys at the [launch zone]. Concerned about the landing wind conditions he was thinking whether or not he wanted to launch. Kunio was ready and in a hurry and decided to go to the north launch. I was with Mark Knight at the south launch holding wing wires and Mark Knight was holding nose wires waiting for Randy's decision. Both Mark and I wanted to see Kunio launch so as soon as we got someone to take our place, we started over. We had not gone 10' when I heard "Kunio just launched". I stopped and looked and got my first glance at him. Then all hell broke loose. "He's unhooked, shit..." Guys yelling at him over the radio to throw his chute, "Kunio don't think, throw your chute throw your chute". We all watch in horror not believing this was happening.
...before anyone back at launch has a fuckin' clue that something is wrong.
...which means you can weight shift.
Of course you can. You can use the traction of your feet on the ground to push your mass off to the side and the effect will be identical to that created by the traction of a towline pulling your mass to the side. Unresisted with torque on the control bar we call this a lockout.
The only difference is, when you're flying at altitude, the glider feels all of your weight when you move it... and when you're still running, the glider is only feeling a portion of your weight...
Bullshit motherfucker.

- You can be running on the ground with the wing flying and supporting anywhere from zero to one hundred percent of your weight. Watch Eric's second launch of the shallowish slope in the light air

http://www.youtube.com/watch?v=t9G8ERElpjM
http://www.youtube.com/watch?v=t9G8ERElpjM

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From standing and commencing with strap and sail slack through running with the wing flying and being totally airborne between widely separated extra thrust push-offs to kissing the ground goodbye for the duration there's no point at which he will do anything different to level his wing.
and for this reason, I agree with you weight shift roll control is limited.
He's not telling you weight shift "control" is LIMITED - dickhead. He's telling you - as does the glider back in the REAL world - that weight shift in the absence of bar torque rolls the glider to the OPPOSITE side.
I disagree heartfelt and fully that it matters whatsoever whether weight is shifted by pushing or pulling on the control frame, or my using our legs and feet on the ground.
How heartfelt, motherfucker? Enough to produce a video showing what you say happens actually happens?
If the glider is lifting some of the pilot's weight... then moving that weight laterally moves the CG/CM of the aircraft (because the aircraft is the pilot+wing... or while running, at least the portion of the pilot being pulled up by the lifting wing)
Got me convinced. Next time I see one of my students getting sideways to the tow I'm gonna floor it - just the way Mike Robertson helped me out when I came off the cart in a strong crosswind.
But like I just said above... I thought THIS thread was about why a hang glider rolls via weight shift (period)...
Big mistake. Brian started it and put the title in quotes.
...the launching thing is kind of a spin off topic here, don't ya think?
No. It was you who introduced two videos...

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...showing us how gliders could be roll corrected by running to the opposite side without using one's hands.
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Tad Eareckson
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Re: 2016/04/03 Tres Pinos fatality

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=34277
"evidence of that silliness"
Tormod Helgesen - 2016/04/19 09:06:14 UTC

I see torque mentioned as a means of controlling a hangglider. It's true that while you're shifting your weight you're putting a force/torque into the system. BUT that force is only for a split second AND it's nulled by the force you use to stop that motion. (Newtons 3rd, for any force there is an equal and opposite force.) Remember you're suspended from the center of the glider with a flexible strap so you don't have leverage to move the controlbar, you're only able to move your body relative to the bar.
Goddam! You're right, Tormod! I'm gonna run my flexible strap through an aluminum tube so I'll be able to have leverage to move the controlbar while I'm moving my body relative to the bar. That'll make the fuckin' glider do what I tell it to.
So for all practical purposes, the only pilot induced force controlling a hangglider is weight-shift.
Well how you gonna weight-shift while I'm suspended from the center of the glider with a flexible strap?

This is what stupid people do to make the world a safer place for them. They pump so much idiocy and lunacy into conversations that anybody with an IQ in the top half of the double digit range or better is marginalized, no longer able to rub anybody the right way, kicked out of Jack's Living Room.

(Everybody keeping a tally on the number of posts Jack's contributed to the Nancy spawned discussion? And Davis, while there's been not the slightest mention of the Tres Pinos fatality on his own rag, has "contributed" 35 posts to "Fatal HG crash in Tres Pinos CA 4-3-2016". They're all short, mostly:
- substanceless
- pro u$hPa
- Blue Sky infomercials)
Christopher LeFay - 2016/04/19 12:56:31 UTC
Dave Pendzick - 2016/04/18 17:41:20 UTC

The control frame of the hang glider is not a steering wheel by which you turn the glider, it is merely a tool by which you use to shift your weight from one side to the other hereby changing the CG of the aircraft which causes the roll.
Ever rotated the glider around YOUR center of mass in the air?
Just every time I fly.
I have- with the wing not flying and the nose straight up... and not while landing. Close to 90 degree change in "heading". Something to think about.
Ryan Voight - 2016/04/19 05:36:02 UTC

But like I just said above... I thought THIS thread was about why a hang glider rolls via weight shift (period)... the launching thing is kind of a spin off topic here, don't ya think?
Evidently, the cause- the inception -of this line of conversation has not- and I say should not -be divorced from present consideration.
Anybody got some aspirin?
Dave Pendzick - 2016/04/18 19:32:18 UTC

You need two things, airspeed & a loaded hang strap to steer the glider. You get both of those things from running.
That ain't accurate- go fly your glider from the control frame on flat ground without hooking in for a vivid demonstration.
Oh Gawd. He's making one of the points I am.
Tormod Helgesen - 2016/04/19 09:06:14 UTC

Remember you're suspended from the center of the glider with a flexible strap so you don't have leverage to move the controlbar, you're only able to move your body relative to the bar.

So for all practical purposes, the only pilot induced force controlling a hangglider is weight-shift.
That ain't strictly true...
Not STRICTLY... But pretty much on the ball nevertheless.
...either- see the example of twirling the glider like a baton, above. Of course, while in motion, the pilot typically has a certain inertia much in excess of that of the glider; at the same time, aerodynamic forces become "dominate" (hesitant to say "greater").
Ever been in a lockout?
Anyway, as much as I enjoy all this cerebral exploration...
Dizzyingly cerebral.
...somebody needs to demonstrate, on camera, a roll correction while hands-off tractoring the glider. Preferably in calm air. Preferably Ryan.
Ryan's been much too busy working to feed his family to be able to produce or find a proper video illustrating this - as he told Brian the better part of six and a half days ago - 2016/04/14 03:41:18 UTC. Just endless posts assuring us that it does and how effective it is.
You might start with the wing tipped a couple degrees off to one side, then cause the glider to roll to center- or, better still, roll in the opposite direction! -merely by pulling on the hang strap. This simultaneously tests "Pud"'s lock-out theory- so a "twofer".
Thank you Christopher - but you're still banned.
Erik Boehm - 2016/04/19 13:00:06 UTC
Ryan Voight - 2016/04/18 15:56:56 UTC

Well when CM moves to one side, we have a "heavier" wing and a "lighter wing"...
This is true at first glance...
Not my first glance - motherfucker.
...but there are assumptions that do not hold.
Read: It's bullshit.
That assumes the whole system can be treated as one single mass, which only works if the masses are rigidly (or at least semi-rigidly) attached to each other.
Rubbish. We ARE semi-rigidly attached to our gliders. And when the shit hits the fan we tend to be extremely semi-rigidly attached to our gliders. And the glider has no way of measuring the rigidity of the connection at any given moment.
You can't treat everything as one mass just because of some physical contact...
Yes you can. If the glider's flying and the suspension's loaded you can, at any given moment, identify the center of mass of the system. If the glider goes weightless and you're not maintaining a significant grip on the control bar your mass becomes irrelevant to the glider's and what it's doing but otherwise...
...just like you don't consider the mass of the tow system when calculating CoM just because you've got a line going to it (or even more ridiculous, considering the Earth's mass when calculating CoM, just because your feet are on the ground during the run)
You BETTER fuckin' consider the force (pressure) the towline is exerting on the pilot and vicinity of the suspension point when you're doing the math. The whole idea of mass is irrelevant in the absence of external forces acting on it. If you launch yourself off the International Space Station on a hang glider you'll just be another piece of space junk. On the other hand, you could have a little RC glider model IN the ISP and tow and control it just fine 'cause towline tension functions as artificial gravity - it's A vector down here on the planet and THE vector in orbit it a contained atmosphere.
If its just the hangstrap, then the force is only transmitted to the center of the wing, and the load is equally distributed to each wing.
Bull's-eye. (Paying attention to this, Ryan Instant-Hands-Free-Release Voight?)
With your hands, you can exert a force on the control bar that winn increase tension on the flying wires to one wing...
There's only one flying wire going to one wing.
...and decrease tension on the other...
As we morph back into singular here.
...which is exactly the situation when a PG increases the loading on one half of its lines while decreasing the tension on the other.

If you move your body to the side by pulling against the control frame, you will have different effects than if you move your body to the side by pushing against the ground.
(Paying attention to this, Ryan Instant-Hands-Free-Release Voight?)
Ryan Voight - 2016/04/18 15:56:56 UTC

It's now believed that a hang glider's wings do not deform to act as ailerons might on a traditional aircraft... but that the deformation occurs AFTER the wing begins rolling, and is due to the changes in relative airflow on each side. Watch a video of a hang glider turning, from behind, and notice the sail does not deform at the time of weight shift, but only after the wing begins to roll. It blew my mind, too...
You act as if this is mutually exclusive when it isn't. In this example, you still have the deformation of the wing, and I'm guessing the nuances you refer to include the delayed response to a roll input. This could be explained by the initial response of only the effects of weight-shift, followed by the effects of deformation of the wing.
This "theory" you talk about is really quite irrelevant to the question of rolling a glider just by pulling through the hangstrap from different directions, without applying forces to the control frame.
The whole idea is to bog the discussion down with lunatic crap to distract the reader away from the fact that Ryan's stated...

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.
michael170 - 2012/09/26 19:52:56 UTC

Are you sure about that, Ryan?
Ryan Voight - 2012/09/26 20:05:16 UTC

You were never taught to run toward the lifting wing?

Yes, I'm sure.

I can (and have) run across a field and steer the glider without ever touching the DT's by simply changing the direction I run. At the beach (or South Side) I like to practice kiting my wing with no hands, and just moving my hips (and stepping if necessary) left/right.

Pulling the hang loop to the right is pulling the hang loop to the right- glider don't care if you're dangling beneath it or still touching the ground. As long as your mains are tight, you can weight shift it!
...and won't, refuses to, can't produce a single frame of video evidence to support that total crap.
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Tad Eareckson
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Re: 2016/04/03 Tres Pinos fatality

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=34277
"evidence of that silliness"
Brian Scharp - 2016/04/19 15:25:24 UTC
Mike Lake - 2016/04/18 21:32:16 UTC

If you are running without holding onto the control frame you are simply towing the glider from the hang point with a very short tow line.
Any misalignment (great word that) is the very seed of a lockout. Running towards the upwind wing only serves to increase the misalignment.

If a tow pilot turns to the right and the tow vehicle turns to the left to compensate I don't think anyone would doubt that this would be an unwise manoeuvre.
Same thing, longer towline.
That's a silly correlation. You're just setting another good example of "you don't know what you don't know". So the glaring question then is, pud- do you tow ever, and with whom?

http://www.hanggliding.org/viewtopic.php?p=386251#386251
http://www.hanggliding.org/viewtopic.php?t=34243
Fatal HG crash in Tres Pinos CA 4-3-2016
Ryan Voight - 2016/04/13 21:24:53 UTC

Brian also sets us a good example of "you don't know what you don't know", thinking he's clever and pointing out a contradiction in my posts, when in reality he's actually pointing out his own lack of understanding.

Which isn't his fault! Hard to fault someone for not knowing something that was never taught to them... and he didn't ask at first because he thought he understood. It's human nature and we all do it, right?!

The glaring question then is, Brian- do you tow ever, and with whom?
2016/04/13 21:32:31 UTC - 3 thumbs up - Christopher LeFay
Dave Pendzick - 2016/04/19 15:33:48 UTC
Christopher LeFay - 2016/04/19 12:56:31 UTC

Ever rotated the glider around YOUR center of mass in the air? I have- with the wing not flying and the nose straight up... and not while landing. Close to 90 degree change in "heading". Something to think about.
What are you talking about Mavi?
That ain't strictly true, either- see the example of twirling the glider like a baton, above. Of course, while in motion, the pilot typically has a certain inertia much in excess of that of the glider; at the same time, aerodynamic forces become "dominate" (hesitant to say "greater").
WHAT THE HELL ARE YOU TALKING ABOUT!?!?!?
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Brian Scharp - 2016/04/19 17:22:41 UTC
Tormod Helgesen - 2016/04/19 09:06:14 UTC

Remember you're suspended from the center of the glider with a flexible strap so you don't have leverage to move the controlbar, you're only able to move your body relative to the bar.
Your off centered weight against the control frame is leverage.
Not if you're hanging from a flexible strap. Ya gotta run it through an aluminum tube if you wanna play the leverage game.
Christopher LeFay - 2016/04/19 17:56:51 UTC

I flew straight up, at apogee (no velocity) rotated the glider around my considerably greater mass, pointing the left wingtip down. My one-and-only hammer-head stall.

Many things seem "crazy" (or magical) when not understood; I suppose the "!" and "?" was about "twirling the glider like a baton"; you can do the same thing with a glider, if there is no airflow- or to a lesser degree, with airflow... as when ground handling. As to inertia, need we address it?
And you always go outta your way to express everything with such unambiguous clarity. What's wrong with that asshole?
Mike Lake - 2016/04/19 19:22:34 UTC

My CV?
I tow all the time especially if it's warm. Two days a week or more at the moment provided my bones will take it.
I'm a rated winch operator and tow coach in the lovely flatlands of Suffolk, England.

I also have experienced such delights as frame towing, payout winches, static winches, just about every bridle configuration known to man, one point, two point, err three point, even eight point (if you include all my harness strings).

I know how to put pressure on a tow line by squeezing it between my figures (not that that achieves much) and tension on the line by pulling it (which is actually much better for flying).

I'm an oldish, greying, unfit, crap flyer from the '70s with an XC fetish. Fortunately I can still recall the essential knowledge that if a glider goes out of alignment, regardless of how long the tow line is, it's not a very good idea to take action to make it go out of alignment even more because if you do it will go out of alignment even more more.
Any thoughts on using a Rooney Link to increase the safety of the towing operation?
Rolla Manning - 2016/04/19 23:20:35 UTC

Simple question, how do you control a flex wing glider?
Rotate to upright and put your hands on the control tubes at shoulder or ear height for better leverage.
Simple two word answer!
Anyone?
Asymmetrical wingloading - dickhead. I know that's three words but I wasn't able to pare my answer down to just two.
Jim Gaar - 2016/04/19 23:43:45 UTC

Weight shift...
I believe he meant control it for sustainable flight - but I've been wrong before.
Ryan Voight - 2016/04/19 23:44:45 UTC

Controlbar Torquing? Image
Rolla Manning - 2016/04/19 23:51:21 UTC
Weight shift...
Bingo Image
Dickhead.
What is this a picture of?

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It's a crappy low resolution screen shot of:

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Ryan Instant-Hands-Free-Release Voight correcting a roll...

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...without torqueing the bar with his hands on which some kindergartener has put a green crayon mark.
Simple two word answer again!
Angled suspension.

Wanna see some more angled suspension - motherfucker?

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How come this Peter Holloway victim ends up going the other way...

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Dickhead? What predictions could you have made about what the glider was or would be doing if I'd just shown you the angled suspension?
R6crys - 2016/04/20 00:10:30 UTC
Maine
Joined: 2016/04/17

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Wanna join a forum on which you WON'T be confused?
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Tad Eareckson
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Re: 2016/04/03 Tres Pinos fatality

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=34277
"evidence of that silliness"
Bouyo - 2016/04/20 00:32:50 UTC

It's kind of ironic that a forum full of highly experienced HG pilots can't agree on the simplest functioning of their wings!
So what's that say about the:
- value of experience
- quality of instruction from:
-- highly exprerienced instructors like:
--- Pat Denevan
--- Joe Greblo
--- Mike Robertson
--- Steve Exceptionally-Knowledgeable Wendt
--- Jim Keen-Intellect Rooney
--- Bart Weghorst
-- usefulness of Dennis Pagen books
- integrity of the u$hPa
- collective intelligence of hang gliding culure in general and glider forums in particular
Here's my two cents (not two words sorry):
Fuck you. This is hang gliding. If you can't explain an aeronautical concept in two or fewer words it ain't worth our attention.
When you pull on the control frame you move yourself and NOT the gilder in a roll input.
I can't stand in one place in dead air or a lifting breeze, pull on the control frame and move the glider relative to me and the planet on which I'm standing? And I can't run in a straight takeoff line and correct rolls? I can't stand at the top of a dune in a 25 mile per hour breeze and correct and/or induce rolls before nosing the glider up and climbing out into the lift band? Fully airborne if I initiate a roll the glider won't move in relation to my mass?
You DO move the glider when you pull forward or back and change it's angle of attack.
What if I roll and push out at the same time for a coordinated turn? Wouldn't that tend to confuse the glider and trick it into to moving in a manner it knows it shouldn't?
When you load your wings asymmetrically the heavier loaded wing flys faster and produces adverse yaw, but then the sail billow increases and makes the loaded wing produce less lift than the unloaded wing, hence a roll moment occurs.
The sail billows isntantaneously - idiot. That's most of what makes it go faster - EXACTLY the way things work with ailerons.
If you doubt any of that, then ask yourself what happens to the roll and lift ability of a glider with full VG on (tighter sail).
The same goddam thing - less effectively.
If the sail billow wasn't responsible for creating the asymmetric lift (rolling), and if it was all down to weight distribution or even torque applied to the control frame, then you could roll a stiff sailed gilder no problem, but you can't.
The billow shift IS responsible for creating the asymmetric lift. And the asymmetric weight distribution is responsible for the billow shift. And the asymmetetric lateral forces applied by the pilot to the control frame and sidewires bracing it is responsible for the asymmetric weight distribution - you moron.
Someone tell me I'm wrong!
You're on The Jack Show. For every one individual who tells you you're wrong they'll be thirty telling you're abso fuckin' lutetly spot on and complaining to Jack about the know-it-all asshole who's rubbing everybody the wrong way.
Rolla Manning - 2016/04/20 01:29:00 UTC

Bouyo, You have to start with post #160 on the thread link here:
http://www.hanggliding.org/viewtopic.php?t=34243
and read through several pages.
in order to figure out what this thread is about.
http://www.hanggliding.org/viewtopic.php?t=34243
Fatal HG crash in Tres Pinos CA 4-3-2016
Brian Scharp - 2016/04/13 18:08:33 UTC
Christopher LeFay - 2016/04/13 17:26:10 UTC

We can't afford to squander this moment, leaving scrupulous instructors to fill in knowledge gaps by trail and error- good people who just don't know what they don't know.
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.
Ryan Voight - 2016/04/06 22:08:19 UTC

Does the tow operator instinctively try to "pull" the student back on course with the winch- which actually would do the opposite, accelerating them into deeper trouble.
1. What does knowing what the thread's about hafta do with addressing basic aeronautical theory?
2. So I take it you're totally on board with his post? Or did you skip over it when you got to:
Here's my two cents (not two words sorry):
Bouyo - 2016/04/20 02:02:05 UTC

Seems like you're upset with Airthug's contention that he can maneuver the glider by running in certain directions, and correcting for roll without pulling on the control frame (with tight hang straps of course).
Nah. We think it's great. We just wanna see a video of him or one of his students doing it so we can learn how to pull it off.
I think Airthug is right. I've done this practice myself as well...
Oh good. Then you can post one of your videos and Ryan can get back to feeding his family.
...and you can too by running fast with your glider in a field.
Oh. Just in a field. And ya gotta be running fast. I was hoping to use it for starting out on mountain slot launches in tricky air when I'm starting my runs. If I've gotta be running fast I might as well just take off at that point. Bummer.
Not sure where this is going now ...
Farther south now with your participation.
Rolla Manning - 2016/04/20 02:06:51 UTC

100% WRONG assumption on your part. Image
Hang in there, you'll see.
Still waiting on the two word answer.
Here I will help those out that can't use just two words
_____ ___ to the left.
First word - five letters. Second word - three letters. I got nuthin'.
Rick Maddy - 2016/04/20 04:25:08 UTC
Dave Pendzick - 2016/04/18 16:33:25 UTC

In a vacuum, like the moon, a feather & hammer will fall at the same rate. Here on earth, heavy shit falls faster. I have witnessed this in skydiving many times.
Sorry but this isn't true (the 2nd part) in general.
It fuckin' IS true in general.
Of course there are many cases where a heavier object will reach the ground before a lighter object here on Earth.
I'd say the vast majority of them.
But there are plenty of examples where a lighter object will hit before a heavier object.
Those tend to be the exceptions, the special cases. An arrow versus a steel garbage can lid.
It's all about air resistance, not weight (or mass).
It's all about BOTH.
I didn't see anything that shouldn't have been pretty fuckin' obvious to a halfway competent pilot. But, for The Jack Show...
Tormod Helgesen - 2016/04/20 06:05:53 UTC
Brian Scharp - 2016/04/19 17:22:41 UTC

Your off centered weight against the control frame is leverage.
No, because of Newtons third law again.
YES, because of Newton's third law again.
The force you're applying to the control bar is opposed by an increase in the tension in the hang strap so the net leverage is zero. The weight has shifted though.
The force you're applying to the control bar is opposed by an increase in the tension in the hang strap which is distributed to the keel which is opposed by the keel pocket which is opposed - with somewhat limited success 'cause it's not fixed in position all that well - by the sail:

07-0911c
Image

So the sail is pulled from right to left to the limit of what the pilot wants to or can do.

Meanwhile the control bar motion is opposed by an increase in the tension of the sidewire on the side towards which the pilot is pulling himself which is opposed by a pretty hefty bolt at the leading edge - cross spar junction. Thus the pilot is able to hold his weight off center under the wing he wants to go down as he would if we were lying in a hammock and pulling on a rope tied ten feet up to a tree off to the side.
All this shit works in concert and simultaneously - ain't we lucky - and the only fly in the ointment is adverse yaw which Wilbur and Orville dealt with by using a rudder and we deal with by using a swept wing.
Ryan Voight - 2016/04/20 11:42:47 UTC
Bouyo - 2016/04/20 00:32:50 UTC

If the sail billow wasn't responsible for creating the asymmetric lift (rolling), and if it was all down to weight distribution or even torque applied to the control frame, then you could roll a stiff sailed gilder no problem, but you can't.
Picture for a moment...
If you produced a video of what you've told us all what you can do so easily we wouldn't hafta be picturing anything for a moment.
...holding a hang glider underwater, and rolling it- one wing lifts up, one wing lowers down. When you roll the glider, you're moving the airframe, so the leading edges of each wing move, obviously.
You wouldn't be able to do this unless you were wearing lead boots. So also picture yourself for a moment wearing lead boots and breathing through gills.
But the trailing edge is unsupported, so the wing that lowers ends up washing out more, and the wing the raises ends up flatter.
Why do we hafta do this at the bottom of a swimming pool? Why can't we do it at the top of a hill in a nice breeze?
When flying, rolling the glider increases the angle of attack (relative airflow) on one side, while decreasing it on the other... and the unsupported trailing edge reflects this- like the underwater example.
Duh.
*IF* hang gliders truly roll because of the offset of lift and CG... and the sail deformation is a side effect of the wing rolling through the air (which I initially strongly objected to- but after studying a buttload of video-
Speaking of video...
...I'm a total believer!)...
1. Yeah, who'da thunk.
2. And a total few other things that come to immediate mind.
...then loose/tight VG, and the resistance of the wing to roll, makes perfect sense!
Every bit as much sense as your claim that you can roll control the glider without using your hands while running across a field. So none of us need to see a video depicting this now.
Tormod Helgesen - 2016/04/20 06:05:53 UTC

No, because of Newtons third law again. The force you're applying to the control bar is opposed by an increase in the tension in the hang strap so the net leverage is zero. The weight has shifted though.
Is that kind of like bending down and grabbing your ankles, and trying to pick yourself up?
No motherfucker. It's kinda like hanging on the middle swing of a three-swing swing set with ropes tied to the ends of the pipe supporting the swings and staked down tight beneath you in the middle. Grab the one to your left and pull yourself sideways. The left end of the beam will feel more weight, the right end will feel less, and if the ground is saturated and soft enough you'll be able to achieve a bit o' roll.
Or like trying to push yourself while hanging on a swing? Push on the chains all you want, it don't make you swing! Move your CG... and something starts happening...
See above, boychick.
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Tad Eareckson
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Joined: 2010/11/25 03:48:55 UTC

Re: 2016/04/03 Tres Pinos fatality

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=34277
"evidence of that silliness"
Dave Pendzick - 2016/04/20 15:06:26 UTC
Rick Maddy - 2016/04/20 04:25:08 UTC

Sorry but this isn't true...
I come from a skydiving background...
Shoulda used more supplemental oxygen for more of those really high altitude jumps.
...& we use a tool called a space ball which is a essentially a tennis ball filled with BBs & has a streamer attached to its surface. Its used as a reference point as it falls perfectly straight down.
No it doesn't. It'll be affected by the wind - same as anything else falling through the air. Think Norden Bombsight. Not enough to matter for the purpose of what you're doing but...
If what you are saying is true, why is the only difference between the 170mph space ball & the 135mph space ball weight & not streamer length????
I can design an arrow configuration missile the weight of your 135 which will leave your 170 in the dust. Also... You can freefall as slow as 120 and I'm assuming most of you guys weigh more than the 135.
Davis Straub - 2016/04/20 15:14:07 UTC

OMG.
Thanks for your carefully considered contribution to the discussion, Davis.
Steve Corbin - 2016/04/20 15:26:19 UTC

I have always thought that the billow shift happens as the pilot's mass is moved, and not as a result of the glider rolling.
Keep thinking that. You'll be fine.
This is all quite interesting...
So's a train wreck.
...and I for one appreciate your coming back to the org.
Me too. 'Specially when he says stuff. Makes him a lot easier to dismember.
I don't at all mind finding out I had the wrong idea.
You should. If you had the wrong idea all these years you sent a lot of student off with deadly misconceptions.
I'd really like to see these videos you're speaking of.
I'd really like to see the video Ryan doesn't have the time to produce.
Brian Scharp - 2016/04/20 16:33:50 UTC
Rolla Manning - 2016/04/19 23:51:21 UTC

What is this a picture of?
It's a harness suspension offset to the left and a glider in a slight right bank. If there's not a hand resisting the glider's steepening roll, the right wing will hit the ground.
Rubbish.

05-0907
http://c2.staticflickr.com/2/1634/25820929693_34fbcc0744_o.png
Image

Ryan's only got his hands on the tube to hold the nose down. 'Cause when you shift your weight FORWARD under the NOSE by running forward the nose goes UP. It's not like when you run shift your weight to the left by running to the left and your wing goes DOWN.
Brian Scharp - 2016/04/20 16:42:35 UTC
Bouyo - 2016/04/20 00:32:50 UTC

Here's my two cents (not two words sorry)...
If you think you can reverse a rolling flexwing merely by exerting a lateral pull in the opposite direction, please video it.
You can't capture this kinda stuff on video. It's like vampires and mirrors. Or emperor's clothes.
Brian Scharp - 2016/04/20 16:50:14 UTC
Tormod Helgesen - 2016/04/20 06:05:53 UTC

The force you're applying to the control bar is opposed by an increase in the tension in the hang strap so the net leverage is zero. The weight has shifted though.
I wish it went to zero.
Get a Falcon. That's the glider Wills Wing designed for all the faggots who...

http://www.hanggliding.org/viewtopic.php?t=34243
Fatal HG crash in Tres Pinos CA 4-3-2016
Ryan Voight - 2016/04/17 04:48:42 UTC

Also, just briefly touching on the whole torque/what makes a glider turn thing... I'll try to be kind and say that I find it most unlikely that our gliders turn because of the minimal rolling torque pressures...
...couldn't even handle big boy minimal rolling torque pressures.
The force remains as long as I'm pushing or pulling.
I remember back at the end of the season at Kitty Hawk in '82. In lighter air dune soaring you're doing hard turns at slowish airspeeds back and forth nonstop. My Comet 165's floating crossbar wasn't working to enhance billow shift as well as advertised and gawd did it take muscle.

In September there was a period in which every fuckin' day it was light air soarable for healthy periods and one did not squander opportunities to rack up airtime no matter what one felt like. I was in excellent physical shape but my arms were screaming all the time and every morning I woke up I prayed that the streamer on the flagpole outside the cottage wouldn't be popping in a good direction.
Brian Scharp - 2016/04/20 17:01:37 UTC
Ryan Voight - 2016/04/20 11:42:47 UTC

Picture for a moment...
You can't reverse a rolling flexwing merely by exerting a lateral force to your suspension and making no other contact with the wing.
Can too. You just wait till I get a break from feeding my family and make the video.
Brian Scharp - 2016/04/20 17:04:53 UTC
Steve Corbin - 2016/04/20 15:26:19 UTC

I'd really like to see these videos you're speaking of.
He's not speaking of them because they don't exist.
YouTube is the worst thing that ever happened to u$hPa. Back in the stone age these motherfuckers could say anything they wanted and one would tend to believe them if one had under a couple hundred hours. Now we can see everything that is and isn't there the world over.
Rolla Manning - 2016/04/20 17:54:58 UTC

The method of control on a flex wing glider is weight shift.
And the purpose of the weak link is to increase the safety of the towing operation. PERIOD.
In a running takeoff with the harness suspension lines tight and the wing is not yet carrying the full weight of wing and pilot you still must control the glider by weight shift. You can call it pulling the wing down all you want but it is still weight shift.
So you're saying that it's physically impossible to have a glider to torque a glider to or from a roll when it's on your shoulders full weight or floating above a bit with the suspension slack. If you pick it up cockeyed at launch you've either gotta put it back down on the ground to level it or start your launch run and get it up to the speed at which there's enough tension on the suspension for you to run to the high side and weight shift the wing back down.

I can't find a really good video to illustrate how moronic and certifiably insane this is 'cause people seldom edit their videos to include the hook-in checks they did two seconds prior to launch or anything after they've plopped their gliders down in the LZ and unhooked - but I shouldn't hafta provide such an illustration.
If you can control a flex wing without weight shift get it on video!
Wouldn't a video of Ryan doing what he claims he can do so easily and does so often much more definitively prove your point?
If the pilot pushes the control bar to the right with the right hand only while holding AoA with the left hand, is that not weight shift to the left?
I dunno... Has he shifted his weight? Can he stand with both feet on a bathroom scale and torque the glider from a twenty degree left bank to a twenty degree right bank without spinning the dial significantly?
If the pilot pushes his weight to the left side of the control bar with the harness suspension lines tight with their feet, while controlling the AoA with their hands on the control bar. Is that not weight shift to the left?
Is he using weight or muscle? Could you design a fifteen pound robot - essentially weightless - that you plugged into a wall socket that could be secured to the control frame and be able to pitch and roll the glider into and out of the kinds of attitudes we can encounter in typical foot launches? Could we bolt this assembly to the International Space Station where there's no such thing as weight and achieve solid results?
Or is pulling on the left down tube to shift the weight to the left really the only way possible to control the glider?

Image
There's a difference between weight and weight shift and TORQUE - asshole. Weight we do in pounds and torque we do in foot pounds. And when we do hang glider or conventional fixed wing aircraft control we're doing foot pounds. That's why our control frames are high and we try to hang as low over our basetubes as possible, to the point of going with dangerous side mounted parachutes, Steve Pearson can't control his glider with his hands at shoulder or ear height, and ailerons are way the fuck outboard near the tips.

Better shot of the same frame:

06-0910
http://c2.staticflickr.com/2/1531/26273295910_7ae30345f4_o.png
Image
Steve Davy
Posts: 1338
Joined: 2011/07/18 10:37:38 UTC

Re: 2016/04/03 Tres Pinos fatality

Post by Steve Davy »

The force you're applying to the control bar is opposed by an increase in the tension in the hang strap...
Depends on how you run the experiment.

I hung a three pound weight on a strap that was connected to a load cell at the fulcrum. Using a string attached to the weight I pulled the weight off center being careful to keep the pull string perpendicular to the strap and found that the load on the strap decreased. No surprise there. Second experiment I pulled the weight off center but kept the pull string parallel to the floor, in that case the load on the strap increased. Again, no surprise, but it was a fun and easy thing to do.

PS - I suspect that folks that have a good feel for the glider instinctively don't load up the suspension much more than necessary as it's a waste of energy.
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Tad Eareckson
Posts: 9150
Joined: 2010/11/25 03:48:55 UTC

Re: 2016/04/03 Tres Pinos fatality

Post by Tad Eareckson »

If I understand what you're doing...

- In the first experiment you're heading to zero.

- In the second you're heading to infinity and illustrating how the load on the weak link (and release) increases above half towline on a two point bridle.

http://www.hanggliding.org/viewtopic.php?t=34277
"evidence of that silliness"
Jim Gaar - 2016/04/20 18:10:37 UTC

I think Ryan was saying that in that frame you show Rolla, that his "light touch" was not affecting the wing in that he was just getting the job done by running towards the lifting wing and no real control (weight from his hands) is being applied to the downtubes.
Yeah. That's what he was saying. Can't understand why can't show us a video of a "no touch" instead of a "light touch". See that long green arrow shifting his weight over towards the left wingtip...

Image

...with the little green arrow he's using to run to the left? That should do the trick. And there aren't any little green arrows anywhere near his hands. What's the point of hands on a hang glider...

27-04007
http://c2.staticflickr.com/2/1712/25329473884_1688d05c0c_o.png
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...anyway? If hands were important why would we put our aerotow releases...

07-300
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...within easy reach?

And hey Ryan... Notice the way that towline is helping Ollie weight shift to the right to help him get that wing back down? That's gotta be a twenty degree pull in the desired direction...

15-413
Image

Probably not enough time for the billow shift to kick in and do the job. (Seriously people of varying ages... That's a really excellent example of weight being shifted to the high side, an extremely light touch on the control bar, the glider trimming to what it perceives as gravity, and the billow not shifting in response to the not asymmetrically loaded wings.)
...Ryan correct me if I'm wrong!
Fuck that, Rodie. You've never been wrong about anything. And even when you are it's always somebody else who ends up getting killed.
Brian Scharp - 2016/04/20 18:12:45 UTC
Rolla Manning - 2016/04/20 17:54:58 UTC

The method of control on a flex wing glider is weight shift...
Using your hands (legs or whatever) to push or pull against the control frame (thereby shifting your weight) to roll, is not in contention. He may have used his legs to get there, but without the use of his hands, the glider would've continued to roll right.
http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Jim Rooney - 2011/08/25 04:55:25 UTC

Ditto dude.

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*.
That video shows excellent control.
Obviously because of his extremely light touch.
Tormod Helgesen - 2016/04/20 20:33:36 UTC

Brian scharp: Please show a video of you lifting yourself by your hair. It's basicly what you're advocating here.
Brian Scharp - 2016/04/20 22:04:18 UTC

Exactly, the probability of seeing that video is the same as the one I'm asking for.
Timothy Ward - 2016/04/21 02:19:29 UTC
Dave Pendzick - 2016/04/20 15:06:26 UTC

I come from a skydiving background & we use a tool called a space ball...
Terminal velocity is when drag is equal to weight. You can vary the weight, or you can vary the drag coefficient, or you can vary both.
Skydivers have gotta be even bigger dickheads than hang gliders. Even more of a dickhead magnet, even less in the way of brains required to learn and do it.
Tormod Helgensen - 2016/04/21 05:52:50 UTC

At least you understand that lifting yourself by your own hair is impossible, that's a beginning.
Or maybe skydivers AREN'T bigger dickheads than hang gliders. Who really knows fer sure?
Steve Davy
Posts: 1338
Joined: 2011/07/18 10:37:38 UTC

Re: 2016/04/03 Tres Pinos fatality

Post by Steve Davy »

If I understand what you're doing...
You do. But I am interested to know how I could have written it such that there would be no "If" in your reply.
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