A collection of Videos about Hang Gliding

Re: Fatal hang gliding accident

Postby Bob Kuczewski » Mon Nov 21, 2011 7:13 pm

bobk wrote:So how many innocent people got "disemboweled" over that little mistake?

TadEareckson wrote:Zero.
  ...
So what's your point?

My point is that we all make mistakes, and "disemboweling" people because they disagree will lead to some number of injustices where people get raked over the coals ... for being right.

I'm sure you haven't appreciated when that's happened to you, and your quotes from Jack Axaopoulos remind me that I haven't appreciated it when it's happened to me either. So why do you feel the need to "disembowel" people when all you need to do is show that you've got a better mouse trap? You advertise yourself as "Mr. just the facts and science guy", but you take far too much pleasure in belittling people for that to be true.

I think the answer is that you care far less about the mouse traps and far more about the satisfaction you get by seeing your enemies bleeding to death in your rear view mirror.
Join a National Hang Gliding Organization: US Hawks at ushawks.org
View my rating at: US Hang Gliding Rating System
Bob Kuczewski
User avatar
Contributor
Contributor
 
Posts: 6343
Joined: Fri Aug 13, 2010 2:40 pm
Location: San Diego, CA

Re: Fatal hang gliding accident

Postby ZackC » Wed Nov 23, 2011 8:12 pm

Thanks Tad. I think I'm starting to get this, although all this interplay between gravity, CG, rotational moments, and stability is complicated and I doubt I'll ever have a real solid grasp of it. The confusion I had with the rope/magnet thing was not what would happen but rather why it would happen and why it wasn't a weight shift. I'm now seeing those scenarios as shifting gravity as opposed to the pilot's weight.

Tad Eareckson wrote:I dunno. Conditions were nasty, I'm having a hard time visualizing someone fighting a roll with his hands on the downtubes and letting go of a lot of pressure at a critical moment without a lot of incentive do do so, and I've never before heard of something like this precipitating an incident.

I didn't mean to suggest he transitioned while fighting a roll. The witness said he let the nose up and hopped into the glider as he launched. I'm thinking maybe he transitioned immediately after becoming airborne, letting the glider to trim in order to do so, and then having insufficient speed to deal with the roll.

Transitioning is one of the things I talked to Joe Greblo about. He saw me launch at Garlock and said I transitioned very soon after launching. He was concerned because some pilots he says do this habitually without making a conscious decision of when to transition. He described a fatal crash just off launch of a very experienced pilot in I think Hawaii...the incident sounded very much like Danny's. He thought habitual early transitioning may have been the cause. (I told him I transitioned early at that site because I was flying straight away from the mountain and thus gaining clearance from it and will stay on the downtubes when maneuvering right off launch so it wasn't a habitual reaction...he seemed satisfied with that.)

Tad Eareckson wrote:Somewhat unfortunate example.

Unfortunate if I was trying to illustrate you being wrong, but I thought it was good for illustrating you being willing to admit to being wrong.

Zack
ZackC
User avatar
Contributor
Contributor
 
Posts: 36
Joined: Mon Feb 21, 2011 9:03 pm

Re: Fatal hang gliding accident

Postby Bob Kuczewski » Wed Nov 23, 2011 8:34 pm

ZackC wrote:Transitioning is one of the things I talked to Joe Greblo about. He saw me launch at Garlock and said I transitioned very soon after launching. He was concerned because some pilots he says do this habitually without making a conscious decision of when to transition. He described a fatal crash just off launch of a very experienced pilot in I think Hawaii...the incident sounded very much like Danny's. He thought habitual early transitioning may have been the cause. (I told him I transitioned early at that site because I was flying straight away from the mountain and thus gaining clearance from it and will stay on the downtubes when maneuvering right off launch so it wasn't a habitual reaction...he seemed satisfied with that.

That sounds like Joe, and I think it's good advice.

I'm sorry if I'm repeating this, but Joe often commented that intermediate and advanced pilots end up spending almost all of their time in the prone position. They'll often fly less than a minute or so upright with each hour-long flight. Over time, they lose their upright skills. So Joe has said that advanced pilots should spend some time once in a while just flying around upright to get a sense for how their glider flies in that configuration. If you've got a few thousand feet below you on a booming day, try going upright and pulling in for maximum speed. Try turning and manuevering in the upright position. Spend 5 or 10 or 20 minutes exploring how the glider feels in that position. Move your hands around on the downtubes to see what works best for whatever you want the glider to do. Explore every aspect of flying upright while you've got all the room and time in the world.

I can't say that I do that often enough myself, but I have spent a lot more time shooting imaginary landings a few hundred feet above the cliffs at Torrey than most pilots, and it does make me feel much more comfortable flying in the upright position.

Thanks again Joe!!!   :thumbup:
Join a National Hang Gliding Organization: US Hawks at ushawks.org
View my rating at: US Hang Gliding Rating System
Bob Kuczewski
User avatar
Contributor
Contributor
 
Posts: 6343
Joined: Fri Aug 13, 2010 2:40 pm
Location: San Diego, CA

Re: Fatal hang gliding accident

Postby TadEareckson » Fri Nov 25, 2011 4:40 am

My point is that we all make mistakes...

1. Yeah, we do. All the time. Which is precisely why when people get told that "just prior to launch" means do a hang check at the back of the ramp some of them WILL die.

2. The mistake I made in this case was capable of physically hurting no one - and I don't think I had even voiced it before. It would change NOTHING about how one designed, equipped, flew, controlled a glider.

3. Zack told me you're wrong because and I IMMEDIATELY said LIGHTBULB, thanks.

4. If Zack told me you're wrong because..., you moron I'd have still IMMEDIATELY said LIGHTBULB, thanks.

...and "disemboweling" people because they disagree...

I don't EVER disembowel people people because they disagree with me. I disembowel people because they disagree with Sir Isaac, put out dangerous misinformation, refuse to participate in rational, honest discussions, lie, cheat, and steal, and/or resort to edit, lock, delete, and ban buttons when it starts becoming obvious that they're evil scumbag morons.

...will lead to some number of injustices where people get raked over the coals ... for being right.

1. BFD. s*** happens when people exercise free speech rights. And more s*** happens when they're denied them.

2. I've been getting "raked over the coals" for being right for decades. But I'm not the one who repeatedly needs to have his body removed from the side of the runway or recovered from the rocks below launch. And it hasn't affected my ability to continue to be right. In fact, all it does is hone my skills in presenting solid cases and dealing with idiots.

3. It's IMPOSSIBLE to get raked over the coals if you're on the same page with Sir Isaac. The people who attempt to only succeed in making themselves look like the morons they are to others in the Sir Isaac camp.

I'm sure you haven't appreciated when that's happened to you, and your quotes from Jack Axaopoulos remind me that I haven't appreciated it when it's happened to me either.

Neither of us have ever been raked over the coals by Jack or any of his cult for being right. We were both stabbed in the back by a stupid, evil, lying scumbag when and because it was becoming obvious that we were right.

So why do you feel the need to "disembowel" people when all you need to do is show that you've got a better mouse trap?

1. That statement is off the scale stunning evidence that you have absolutely no freaking clue about what happens and is happening in the REAL world.

2. If you go to the public airport and start showing people you've got a better mousetrap you can expect to be blacklisted by the Flight Park Mafia cartel and have your aerotowing career ended. You need enforcement of existing regulations, accountability, lawsuits, jail time to start making things happen on any measurable scale. And unless/until ya can make any of that happen, ya go with disembowelings.

3. I don't EVER disembowel people who are engaged in honest rational discussions with me. If you wanna increase the disemboweling activity then just keep telling people like Peter to ignore what I'm saying and not bother addressing my points.

4. What's happening now has very little to do with mousetraps. Peter's got a pretty good mousetrap and I recommend it to people for certain applications. What's happening now is mostly about getting Peter to understand that Sir Donnell was and is seriously and dangerously out of touch with Sir Isaac.

You advertise yourself as "Mr. just the facts and science guy", but you take far too much pleasure in belittling people for that to be true.

Is it carved in granite somewhere that these are mutually exclusive profiles?

I think the answer is that you care far less about the mouse traps and far more about the satisfaction you get by seeing your enemies bleeding to death in your rear view mirror.

Yeah, so? Better mousetraps, evil lying scumbags bleeding to death - either or both accomplishments increase my nephew's chances for survival. And, unfortunately, the former will NEVER happen without a good measure of the latter happening first.
TadEareckson
User avatar
Contributor
Contributor
 
Posts: 456
Joined: Fri Feb 11, 2011 9:07 am

Re: Fatal hang gliding accident

Postby Bill Cummings » Sun Nov 27, 2011 1:17 pm

3. And whereas two hands on the basetube and fractions of a second were critical BEFORE the new Lookout GT (Gone Tomorrow?) Aerotow Release didn't...

(Gone Tomorrow?) :srofl: :srofl: :srofl: :srofl:
Bill Cummings
User avatar
Contributor
Contributor
 
Posts: 2916
Joined: Wed Jul 13, 2011 6:20 pm
Location: Las Cruces NM 88005 (Region 4)

Re: Fatal hang gliding accident

Postby brianscharp » Wed May 11, 2016 11:38 am

Bob Kuczewski wrote:
ZackC wrote:Last year I went to a clinic in Utah hosted by Ryan Voight. Ryan's into aerial photography and on a down day we were discussing camera mounts. He had a mount that attached to the base tube and extended out a ways in front of the pilot pointing aft. He said you didn't have to counterweight it because as far as the glider was concerned all the weight was on the base tube where the mount attached. I wasn't sure about that and Ryan isn't the most trustworthy source with regards to physics but he apparently had experimental verification that was the case so I went with it. It never occurred to me to apply that same principle to our hang points.

If the situation was as you describe it, then Ryan was absolutely wrong (or you misunderstood what he was saying). The torque applied by a weight attached forward of the base tube does affect the glider. He may have gotten away without counter-weighting because it was relatively minor (torque is force times lever arm ... as in "foot pounds"). If the arm wasn't too long, and the weight was relatively light, it might have been unnoticeable, but that doesn't mean it was zero. More importantly, a statement like that can plant dangerous misconceptions in his student's minds.

ZackC wrote:It's well known that if you put a heavy camera on a leading edge out near a wingtip it will cause a roll tendency. If the camera was in the same position but mounted to a beam attached to the keel at the hang point instead of the leading edge it would not (I think). If that's the case, the actual shifting of weight that occurs in a roll can't be the cause of the roll because the pilot is still attached to the same point on the glider. For a true weight shift roll to occur the hang point would have to move laterally.

This doesn't sound quite right to me. I believe the camera attached to the beam from the keel will still impart a rolling torque on the glider. Also, when the pilot shifts, his hands are applying a torque to the glider through the base tube (or down tubes). That's what allows him to shift his weight in the first place. So you can't really separate the two. You may be confusing this with a tow line situation where the force is just along the line because that's the ONLY connection between the glider and the tow force.

ZackC wrote:Even if I accept that shifting weight isn't responsible for a glider's response, there are still some things I'm not clear about. The control frame is fixed to the keel...what causes the left wire in your example to tighten? What causes the slop transference? If the roll is caused entirely by wing warping, how does differential wire tension effect pitch changes (which, to my knowledge, are not caused by wing warping)?

I think weight shifting is responsible for the glider's response. I believe that shifting weight applies a torque to the glider through the pilot's hands which is rolling the glider. The interplay between the torque and the wing warping is a little more confusing, but I believe that the torque is the prime mover in this situation.

http://www.hanggliding.org/viewtopic.ph ... 428#386428
AIRTHUG wrote: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 we are applying through the control frame. I will also present evidence of that silliness- Follow the forces! To move your weight left, you are pushing the base bar to the right. The base bar isn't able to go to the right, primarily because of the left side wire. Tension on that wire might be increased, but the cross-bar/leading-edge junction isn't pulled toward the corner bracket, primarily because of the upper side wire running to the kingpost. Possibly tension on that is increased, but the top of the kingpost isn't able to move toward the left cross-bar/leading-edge junction because of the upper right flying wire. Keep going in your mind, until you get back to the base bar... (it's a closed system folks).

http://www.hanggliding.org/viewtopic.ph ... 864#295864
AIRTHUG wrote: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.
brianscharp
User avatar
Contributor
Contributor
 
Posts: 267
Joined: Tue Nov 11, 2014 12:49 pm

Re: Fatal hang gliding accident

Postby Frank Colver » Wed May 11, 2016 11:46 am

It physically doesn't matter where a mass it attached, it is the position of the mass itself that determines the CG of the object it is attached to. Attaching the weight of a camera to either the LE or keel would make no difference if the camera itself is in the same position in relation to the rest of the glider. That is why shifting of the pilot's weight affects roll and pitch even though the hang point attachment doesn't move.

There is no magic in physics. ;)

FC
Frank Colver
User avatar
Contributor
Contributor
 
Posts: 1144
Joined: Tue May 24, 2011 11:21 am

Re: Fatal hang gliding accident

Postby Bob Kuczewski » Wed May 11, 2016 1:08 pm

Frank Colver wrote:It physically doesn't matter where a mass it attached, it is the position of the mass itself that determines the CG of the object it is attached to.


Frank is correct. This sketch (viewed from the rear of the glider looking forward) might help:

Camera_Torque.png
Camera_Torque.png (11.25 KiB) Viewed 4564 times


It doesn't matter if the camera is attached to the leading edge (top - in green) or some camera strut or "beam" (bottom - in blue). The glider will feel the same amount of torque applied about the keel ... at least when the glider is horizontal (when the glider is rolled, the vertical offset between the two positions changes the horizontal offset as a cosine of the roll angle).

Pictures speak a thousand words, and I think if Zack were to consider applying a downward force on either lever arm in the picture, he would conclude that the rolling force would be the same. Sometimes words can confuse the matter and that's what I think has happened here. That's why I stated: "If the situation was as you describe it, then Ryan was absolutely wrong (or you misunderstood what he was saying)". Of course, it could be a little of both.
Join a National Hang Gliding Organization: US Hawks at ushawks.org
View my rating at: US Hang Gliding Rating System
Bob Kuczewski
User avatar
Contributor
Contributor
 
Posts: 6343
Joined: Fri Aug 13, 2010 2:40 pm
Location: San Diego, CA

Previous
Forum Statistics

Who is online

Users browsing this forum: No registered users and 11 guests

Options

Return to Hang Gliding Videos