Weak links

General discussion about the sport of hang gliding
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

Yeah, I need to tear myself away from this forum long enough to...

- set up the load tester and get Antoine some numbers on the Three-String

- put together some bridles and stuff so I can get the tension gauge off to you and stop feeling rotten about that

- locate the slide I took of a Western Kingbird we found on a Christmas Count 33 years ago so Maryland can put another species on the official state records list

I don't think there's any question that the hang gliding industry has degenerated into a massive disinformation generator. Tracy's a goddam engineering professor. He didn't do all the work of setting up and recording a test session which produces such totally useless/misleading information as that one did by mistake. Just like he doesn't walk out of online battles he's obviously gonna lose because he finds the incivility offensive.
Zack C - 2012/08/01 13:56:41 UTC

Don't forget...a good release isn't that important because you can always intentionally break your weak link.
Excellent, if depressing, post.
Starting to wish I had been born with a predisposition to prey upon, appeal to, nurture other people's stupidity rather than fight it. Hard to imagine how rewarding that path must be.
Zack C
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Re: Weak links

Post by Zack C »

Tad Eareckson wrote:- put together some bridles and stuff so I can get the tension gauge off to you and stop feeling rotten about that
Don't sweat it...you're under no obligation and if you want to do it there's no rush.

Zack
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=27809
Tug accident in Ohio
Jim Gaar - 2012/12/19 19:17:01 UTC

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

On November 4, 2012, about 1245 eastern standard time, a Dragonfly-C, N667DF, experienced a total loss of engine power during takeoff, and collided with terrain near Darbyville, Ohio. The pilot, the sole occupant of the aircraft, received minor injuries. The aircraft received substantial damage to both wing spars and the vertical stabilizer. The aircraft was registered to a limited liability corporation and operated by an individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The airplane had just departed the WesMar Aerodrome, Orient, Ohio.

According to a statement provided by the pilot, the airplane was towing a hang glider, and was about 80 feet above ground level when the engine stopped producing power. The hang glider was released and the pilot attempted to perform a forced landing. The engine was retained for further examination.
Steve Baran - 2012/12/19 19:39:28 UTC

The usual cause of such a shut down when I flew ULs back in 70s/80s was lack of fuel due to fuel line shut off (never turned on and engine was only running a short time prior to takeoff). Water in fuel tank can also cause same - especially in winter due to condensation. I also remember a faulty kill switch issue cropping up at one time causing loss of power. Never experienced these myself but saw each happen.

Glad pilots are reasonably OK.

Added .... As for loss of power results ... If most of what produces drag is above the center of mass the craft's nose will rotate upwards. At 80 feet off the ground this can be problematic (stall) - and exaggerated if climb angle is high. Also doesn't help if tug is already over an area where a dead stick landing can't be made safely. I hope we learn more about the entire cause and ensuing consequences.
Craig Hassan - 2012/12/19 20:03:06 UTC
Ohio

What happens when you pump cold water into an engine?

I can tell you, you get a complete loss of power.

The next day everything turns and spins as it should.

Tearing the engine apart you can see the piston and sleeve didn't play nice.

The engine was warmed up, but left to sit for to long before the tow. When the thermostat opened it pumped cold water into the water jacket. The temp difference was enough to cause the motor to cold seize.

Photos were taken shortly after by the pilot's wife. She posted them to facebook.

http://farm9.staticflickr.com/8498/8289751632_6412429f87_o.jpg
Image
http://farm9.staticflickr.com/8224/8288694927_b0504a614b_o.jpg
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http://farm9.staticflickr.com/8501/8289756466_6537ea336e_o.jpg
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The last photo I think was the following day. You can see the pilot in his walking cast in the back ground, and the smashed seat he was in.
Jim Gaar - 2012/12/19 20:22:49 UTC

Ahh thanks. Good to hear the causes!

Looks very similar to our tug accident after getting waked by another GA aircraft that had just done a touch and go.
Steve Baran - 2012/12/19 20:25:26 UTC

Interesting, never have flown a water cooled UL. Would a remedy have been to run the engine up a few times prior to takeoff and/or taxi around a bit?

Looks like the vertical rudder extension may have helped lessen prop damage.
Brad Barkley - 2012/12/19 20:32:49 UTC
Frostburg

I'm glad to know everyone involved survived!! :shock:
Dave Hopkins - 2012/12/19 22:25:55 UTC

Seems the front cage doesn't offer much of a crumple zone for the pilot. When it folds you are in for a bruising. It's good to have small wheels or skids so the cage doesn't dig in if the nose goes down.
Craig Hassan - 2012/12/19 22:34:43 UTC

Letting the engine warm up slow is key. Then you have to let the thermostat open and ALL of the water heat up.

Same thing can happen on cold days if you go to idle and take a long slow decent, or nose down and dive. At idle the thermostat won't open enough and the water in the radiator will cool too much. Hit the throttle and bam! It is not a sputter and die. There is no partial power loss. It is lights out for the engine. I'm told it leaves a tell tale scarring on piston and sleeve.

I think I read somewhere you can run a bypass of some sort so there is always a bit of water circulating. This helps keep the water in the radiator from cooling to much.

This is actually the second accident for our tug. First time the bridle got draped in front of the elevator. On roll out it caught in the tailwheel and wound up. It pulled, and locked, the rudder in a full deflection.

Happily our tug pilot walked away both time with little to no injuries. Sadly he may be done being our tug pilot. He has been a huge, HUGE part of our club. Not sure where that leaves us. Waiting on insurance and tug owners to decide. Talk of a couple ultralight tugs, but we will see.
Dennis Wood - 2012/12/19 22:38:04 UTC
Suffolk, Virginia

i've often wondered about a welded chrome moly cockpit for the D-fly. i don't think the weight would be that prohibitive, but not all assembly men are versed in TIG welding.
Dan Harding - 2012/12/19 22:40:13 UTC
Burlington, Washington

Thermostats do not just open to full, or close quickly, unless they are faulty. It is unfortunate that a part as vital as that can not be preflighted. I have seen new thermostats not work as they should and have replaced the radiator because of a bad one.
On November 4, 2012, about 1245 eastern standard time...
So how come we're just hearing about this now?
a Dragonfly-C, N667DF, experienced a total loss of engine power during takeoff...
DUDE!!! A TOTAL loss of engine power during TAKEOFF!!! What an unimaginably horrible experience that must've have been!
...and collided with terrain...
I don't understand. Why didn't he just land?
...near Darbyville, Ohio.
Wings to Fly!
The pilot, the sole occupant of the aircraft...
Who's remaining nameless because?
...received minor injuries.
Bummer.
The aircraft received substantial damage to both wing spars and the vertical stabilizer.
GOOD. That goddam plane and the total douchebags who developed and fly it constitute one of the worst disasters ever to befall hang gliding.
According to a statement provided by the pilot, the airplane was towing a hang glider...
Who, by the way, under the right set of circumstances could've also been seriously fucked up as a direct consequence of this engine failure.
...and was about 80 feet above ground level when the engine stopped producing power.
Try having your Dragonfly mandated standard aerotow weak link blow ten feet off the cart and see how much you like it - motherfucker.
The hang glider was released and the pilot attempted to perform a forced landing.
BOTH pilots had to deal with forced landings. But that's pretty routine for us - motherfucker.
The usual cause of such a shut down when I flew ULs back in 70s/80s was...
Not much fun whatever the cause - is it, ChattaroyMan?
Also doesn't help if tug is already over an area where a dead stick landing can't be made safely.
None of these things are safe. They're all deviations from the flight plan and the FAA defines them - for planes at both ends of the string - as EMERGENCY landings.
The engine was warmed up, but left to sit for to long before the tow.
So pilot error. Right, Craig?
Photos were taken shortly after by the pilot's wife. She posted them to facebook.
Give her a kiss for me. They're GOLDEN.
Looks like the vertical rudder extension may have helped lessen prop damage.
Given what idiot fucking Bobby Bender Bailey designed it to do - AMAZING.
I'm glad to know everyone involved survived!!
Sure. Why not?
Seems the front cage doesn't offer much of a crumple zone for the pilot.
Neither, apparently, does the airframe of a North Wing T2 after the tug does to him what this engine did to this guy. Just ask Jeremiah Thompson's next of kin.
This is actually the second accident for our tug.
That's not even the first "accident" for your tug, Craig.
Sadly he may be done being our tug pilot.
Yeah Craig, I got tired of wondering if I was going to get dumped every time I took off too. Pretty shitty way to run an airline.
He has been a huge, HUGE part of our club.
Fuck your idiot club.
Not sure where that leaves us.
Hopefully grounded - right where you assholes deserve to be.
i've often wondered about a welded chrome moly cockpit for the D-fly.
Maybe the focus should be more along the lines of making sure nobody ever loses power on takeoff - 'cause not all losses of power on takeoff are survivable no matter how good your welders are.
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=27809
Tug accident in Ohio
Bob Flynn - 2012/12/19 23:07:34 UTC

I'm glad the pilot walked (limped?) away. That could have been a whole lot more serious. The engine should have definitely been thoroughly warmed up and a full power check done before committing to a take off. Seems like a procedural oversight maybe.
I think you're onto something there, Bob. Maybe we should really preflight our systems to make sure that the chances of anyone losing power on takeoff are at an absolute minimum.
NMERider - 2012/12/19 23:35:46 UTC

Does anyone know how many Dragonfly tugs are still operating?
Too fuckin' many.
It seems like there have been quite a few wrecks with several fatalities in the past few years. Are we going to run out of stick and rudder controlled tugs at some point and be going up behind trikes?
Oh gawd I hope so. And maybe we can kill a few of the more deserving drivers in the process.
Patrick Halfhill - 2012/12/20 00:04:03 UTC
Pittsburgh

How sad, I towed up with these guys a week or 2 before this incident. It's a great airport with a great club and a great bunch of people. I hope everything gets back on track for spring.
If you like these people it's a no brainer that I feel the precise opposite about them. Fuck you, Pat.
Larry Howe - 2012/12/20 00:19:52 UTC

What kind of engine was in this dragonfly cold seizures are usally not a problem with water cooled such as the Rotax 912 series or the 582, once warmed up the liquid keeps a pretty steady engine temp even when I'm doing touch and goes on cold days. The 503 is air cooled and when free air cooled instead of fan cooled cold seizures can be a real problem if you cut power as in coming in for a landing and then go full throttle as on go arounds. However at 53hp I have a hard time believing a Dragonfly would have a 503. IMO cold seizure was not the culprit, be interesting to find the NTSBs final report.
It would be even more interesting to find out why Keavy Nenninger's Dragonfly slammed in at Ridgely a couple of summers ago - but so far we haven't heard shit.
Glad no one was hurt
Read the reports again and look at the pictures. Someone WAS hurt.
Red Howard - 2012/12/20 00:57:33 UTC

Campers,

I don't know much about ultralights, but if the coolant thermostat-valve can kill an engine dead, that needs fixing.
Can you think of anything else in these operations...

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Davis Straub - 2011/08/26 14:04:52 UTC

We had six weaklink breaks in a row at Zapata this year.
...that needs fixing, Red?
The big Diesel trucks do not have a thermostat-valve that cuts off coolant flow from the radiator. The coolant flows at full volume, at all times. The radiator has louvers that can close to cut off the air flowing through, which regulates the engine temperatures. Yeah, I realize, it's a little more weight and cost, but it could save the tug, so I would opt for safety. A temperature probe in the coolant then would tell you that everything was good, not just the coolant in the engine or in the radiator.

Water in the fuel lines? You can get a fuel filter / sediment bowl that will let you see when water has collected in the fuel lines or tank. A cheap one is pictured below, but they come in all flavors. Find a good quality unit, and drain out any water on every pre-flight. I use in-line glass tube-and-filter-element units on my bikes, which have no drain but they will let you see if there is a water problem.

:mrgreen:

Image
Any thoughts on how we might go about addressing problems like this one?

http://groups.yahoo.com/group/TTTFlymail/message/11545
Cart stuck incidents
Keith Skiles - 2011/06/02 19:50:13 UTC

I witnessed the one at Lookout. It was pretty ugly. Low angle of attack, too much speed and flew off the cart like a rocket until the weak link broke, she stalled and it turned back towards the ground.
Just kidding.
Casey Cox - 2012/12/20 01:45:11 UTC

Seems like that would have been a pretty good time to pull that red handle! Heard of 100' deployment.
- Eighty feet. Good freakin' luck.

- Nobody's gonna be thinking parachute in a situation like that. The pilot's gonna be in full stall recovery mode.

- We need to be focusing on the implications of power loss on takeoff...
Wills Wing / Blue Sky / Steve Wendt / Ryan Voight Productions - 2007/03

NEVER CUT THE POWER...

Image

Reduce Gradually
Increase Gradually
...and ways to minimize the chances of it happening.
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

http://www.hanggliding.org/viewtopic.php?t=27809
Tug accident in Ohio
Craig Hassan - 2012/12/20 01:47:32 UTC

Ok I was running off the top of my head on the cold seize. I believe that I what was determined in the teardown, but my reasoning for the cause of a cold seize may be off.
There's an absolutely astounding wealth of material illustrating the degree to which your "reasoning" is off. (And your proofreading could use a bit of work too.)
It may be more likely with NO thermostat. I don't know if the Ohio tug had a thermostat or not. I would guess yes, but I don't know.
We still have a local with a workhorse trike. To be honest the tow behind the trike is as, if not more, comfortable than the Fly.
We may end up with a couple ultralight tugs.
Good. Get as many as possible of those goddam Dragonflies with their goddam:

- drivers ready to fix whatever's going on back there by giving us the rope, forcing us to fly with illegally understrength weak links, and dictating that we're only allowed to fly with the shitrigged equipment they sell us;

- tow mast breakaways; and

- triple strand tow mast breakaway protectors

out of circulation so more people have a shot at benefitting from the six hundred pound front end weak link they're using at Columbus (Texas - not Ohio).

Here's the report:

http://www.thekathrynreport.com/2012/11/pickaway-county-ohio-pilot-escapes.html
Nancy Radcliff - 2012/11/04

Investigating the scene where a small single-engine aircraft crashed Sunday afternoon are, from left, Deputy Casey Thress, Sergeant Cory Bachnicki and Deputy Erick Eberhard of the Pickaway County Sheriff's Office.

Image

Image

The Pickaway County Sheriff's Office investigated the crash of a small single-engine aircraft at 12:31 p.m. Sunday near London Road, about a mile north of Darbyville.

Larry Lindsey, a witness, said Frank Murphy had just taken off towing a glider when the engine of the 2010 Dragonfly aircraft he was flying failed.

Lindsey said the aircraft was about 80 feet in the air when the engine quit and Murphy managed to bring the aircraft in to a controlled landing about 1,500 feet from where he took off from.

Murphy said the aircraft is worth $20,000 and there was about $10,000 worth of damage to it.

According to Pickaway County Deputies at the scene, Murphy, 57, of Hilliard, was not injured in the crash.
that Jim Gaar discovered about the incident that nobody from that neck of the woods thought worthy of a mention before. (Nice controlled landing, by the way. Plane upside down and half totaled with the pilot's left leg in a cast. I wonder what an uncontrolled landing or a crash looks like.)

Note that we're not hearing the slightest murmur about what an incompetent douchebag this tug driver was the way we always do about a glider that piles in after getting dumped by one of these operations.
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Re: Weak links

Post by Warnarr »

http://www.thekathrynreport.com/2012/11/pickaway-county-ohio-pilot-escapes.html

I get a message saying to log into google blogs to read this?
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

That's odd.
Yesterday - when I found it on a Google search for the N number - it was freely accessible.
When I checked again just now it made me log into my gmail account and then told me:
This blog is open to invited readers only
The good news is that I still had the page open and saved a copy to disk - so I can email it to you if you want. But there's really nothing of substance from it that hasn't already been posted here.
Warnarr
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Joined: 2011/03/31 20:10:40 UTC

fear leads to secrecy

Post by Warnarr »

http://www.hanggliding.org/viewtopic.php?t=27809
Tug accident in Ohio
Jim Gaar - 2012/12/19 20:22:49 UTC

Looks very similar to our tug accident after getting waked by another GA aircraft that had just done a touch and go.
---
Last edited by blindrodie on 2012/12/19 20:25:55 UTC; edited 1 time in total
Where is the NTSB report on this?
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

I dunno. Was the NTSB looking at Dragonfly crashes at whatever point in history that was?
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Tad Eareckson
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Re: Weak links

Post by Tad Eareckson »

http://www.ohioflyers.org/showthread.php?t=1188
Frank Murphy - 2012/11/08 00:43
Hilliard, Ohio

Things I've Learned
Since when, Frank?
I would like to share a bit of hard earned knowledge with all those who aerotow.
This should be really good. I'm trying to think of any knowledge in aerotowing that needs to be hard earned and I'm not coming up with anything.
It may be just me that it escaped...
I doubt it. I've found the depths of ignorance and stupidity one typically finds amongst the people pulling gliders and running aerotow operations to be pretty much unfathomable.
...and if so, excuse my ignorance but...
Sorry dude.

- There's not a whole helluva lot that needs to be understood to conduct a competent and safe aerotowing operation.

- What DOES need to be understood is all ten year old kid common sense stuff.

- There are FAA regulations which cover aerotowing operations which provide for the safety of the people at BOTH ends of the string which one hundred percent of you Dragonfly motherfuckers violate the hell out of with virtually EVERY tow you make.

- Y'all have crashed thousands of gliders and killed a few by:
-- towing:
--- with:
---- inadequate weak links
---- shit equipment
--- totally unqualified glider pilots
-- making good decisions in the interest of the glider's safety

- When you tow a glider you've got a lot more ability to kill him than he has to kill you and you are supposed and need to have your shit together really well BEFORE you start pulling up gliders in anything other than your qualification exercises.

So no. I'm not gonna excuse you on something this fundamental. And I'm even more not gonna excuse the asshole who signed your ticket.
For those who tow:

If you have a complete loss of power during a tow, make the very first thing you do, without a moment of hesitation, RELEASE THE TOW LINE AND DROP THE NOSE.
No shit.
For those on tow:

When the tug is experiencing engine problems, GET OFF THE LINE WITHOUT HESITATION.
That's not the job or the responsibility of the glider. His primary responsibility is the safety of his plane just like your primary responsibility is the safety of yours.

I'm gonna do everything I can to stay in position and make things as safe and easy as possible for both of us but in the unlikely event that I'm in a position to keep you from crashing your plane at a cost of crashing my plane that ain't gonna happen.

You've got a dump lever on your joystick. If you need to use to keep from crashing then use it - and I'll do what I can to deal with my situation. But don't expect me to do your job for you - and please don't do mine for me.
While towing and with a complete loss of power, the tug stalls immediately.
Yeah. The same thing can happen to the glider. So DO make make sure the gliders you're pulling have adequate weak links and make goddam sure that you've got something stronger on your end as per FAA regulations.
Any hesitation to release only amplifies the problem and with no altitude to recover, bad things happen.
So don't hesitate to release. You're almost always gonna be able to beat the glider anyway 'cause Bobby built in a half decent system for his end and used a bunch of chintzy slap on crap for the back.
The Following User Says Thank You to fdmurphy44 For This Useful Post:

Scott Corl
You found that useful, did you Scott? What was it that you didn't understand before?
Mike Flamm - 2012/11/08 01:30
Columbus

Frank,

Just saw a write up in the Circleville paper yesterday. Glad to hear you were unhurt.
He wasn't.
Sorry to hear about the Dragonfly though.
You mean the Dragonfly he trashed by failing to:
- warm the engine up properly; and
- dump the glider and get the nose down the millisecond the engine seized up?
Thanks for the debriefing as to proper action in such an event.
Idiot.
Along that line, I would like to see debriefings offered on the site with all adverse events.
Here. Try these:
Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974

"Never take your hands off the bar." - Tom Peghiny
"The greatest dangers are a rope break or a premature release." - Richard Johnson
"A bad flyer won't hurt a pin man but a bad pin man can kill a flyer." - Bill Bennett
That's pretty much all you need but, of course, if you were capable of getting what's being said you wouldn't be asking for information about aerotowing emergency procedures.
I think it would be extremely educational for all flyers and foster a high level of vigilance in all our activities.
So where have you assholes been when the handful of us who know what the fuck we're talking about have been out on the forums trying to drive some of these points home?
Again, glad you and the glider pilot were unhurt.
AGAIN, he WAS hurt.

P.S. Hey Frank...

http://www.chgpa.org/forums/viewtopic.php?f=2&t=2467
weak links
Jim Rooney - 2007/07/22 22:30:28 UTC

I've heard it a million times before from comp pilots insisting on towing with even doubled up weaklinks (some want no weaklink). I tell them the same thing I'm telling you... suck it up. You're not the only one on the line. I didn't ask to be a test pilot. I can live with your inconvenience.
I thought a standard aerotow weak link was supposed to blow whenever anything went wrong with the tow. What happened? Did the glider sneak in with a doubled loop?
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