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Skarphol
05-11-2006, 12:41 AM
Hi!

Look at this clip: http://www.break.com/movies/wingless1.html

The plane snaps both wings at the same time! How can this happen? It has just pulled a lot of G's and then both wings snap while flying straight and level...

After looking a second time, I'm beginning to think that the pilot just started some kind of manouvre as the wings snapped, but...

DOes anyone has any info on this crash?

Skarpol

HotelBushranger
05-11-2006, 12:49 AM
That is very odd. I would say, not being a plane built for aerobatics the wing's warped under the G forces, and it was only a matter of time before the airflow going over the wings would eventually snap the wings under the pressure.

Edit: Just watching it again, I would say it was a Partanavia P-68 Victor. I've flown in one, and can say I definitely wouldn't take it up for a loop. It was made as a multi-role plane, and having only 2 200hp engines, it wasn't cut out for that sort of stuff.

Have a look at the similar silhouette:
http://www.rescate.com/P68B_Victor_01.JPG

The-Pizza-Man
05-11-2006, 01:02 AM
Looks like a Partenavia, I don't think those things are certified for aerobatics. Did a loop, overstressed the main spar, caused a crack to grow to critical size for the stress put on it in the next attempt at a loop. Consequent brittle failure of the main spar = snap, there go the wings. I wouldn't be suprised if fatigue didn't figure in there as well. The moral of the story is don't try and loop planes not designed for it.
http://www.schemedesigners.com/images/Partenavia-evens-Photo2.jpg

EDIT: Didn't see where you said it was a Partenavia, sorry for repeating you. I've actually flown in one. Just noticed the picture as well, it hadn't loaded by the time I scrolled down.

major_setback
05-11-2006, 01:40 AM
Poor pilot.

HotelBushranger
05-11-2006, 01:58 AM
http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

IL2-chuter
05-11-2006, 04:49 AM
He might have been well over manouvering speed and coupled with a rapid up elevater control input (I agree it maybe looks like a hint of a manouver at failure - could just be induced by failure) you could get this result. Been a pilot for . . . ever http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif and haven't quite gotten myself into a pickle like that. When you're fast (I've been beyond Vne a few times) you really shouldn't be slappin the b*t*h.

I got nothin but speculation.

I would like to read the report.

p-11.cAce
05-11-2006, 06:54 AM
I think it is interesting that both wings failed outboard of the engine nacelles - approximatly where those teardrop fairings are located on the bottom of the wing. What are those fairings there for? Otherwise it looks like an overspeed failure - all wings are built with a twist called "washout" so that the angle of attack of the wing tips is less than that at the wing root: this insures that the root stalls before the tips and is a critical aspect of flight safety. As airspeed increases the lift distribution along the wing span increases near the fuselage and decreases towards the tips - so the spar has to contend not only with greater lifting forces but torsional stresses as well. I'm only speculating but I watched the video over and over and could not tell if the horizontal stab - which faces severe stresses at high speed - failed immediatly before or after the wing. If it failed first the sudden loss of balancing trim would cause a nose-down movement increasing the washout angle of attack symmetrically leading to the wing failure. If it had just been the spar I would think only one wing would fail or perhaps one and then the other. In any case it is sad to see a pilot (or pilots) lose their lives in such a tragic way.

FlatSpinMan
05-11-2006, 07:45 AM
http://forums.ubi.com/groupee_common/emoticons/icon_frown.gifThat's horrendous. Poor buggar. http://forums.ubi.com/images/smilies/16x16_smiley-sad.gif

Owlsphone
05-11-2006, 07:49 AM
NTSB Identification: FTW83FA424 .
The docket is stored on NTSB microfiche number 21677.
14 CFR Part 91: General Aviation
Accident occurred Sunday, September 11, 1983 in PLAINVIEW, TX
Aircraft: PARTENAVIA P68C, registration: N29561
Injuries: 1 Fatal.

THE PLT WAS EXECUTING A HIGH SPEED PASS OVER THE RWY AT ABOUT 250 FT AGL. THE PLT THEN BEGAN A RAPID PULL-UP & BOTH WINGS SEPARATED JUST OUTBOARD OF THE ENG NACELLES. RECONSTRUCTION OF THE SEQUENCE FROM A VIDEOTAPE REVEALED THAT THE ACFT'S SPEED AT THE TIME OF THE WING SEPARATIONS WAS 220 KTS. VNE FOR THE ACFT IS 193 KTS. IT WAS CALCULATED THAT, AT 220 KTS & AN 8 DEG NOSE-UP PITCH, THE 'G' LOAD AT THE TIME OF THE WING SEPARATIONS WOULD HAVE BEEN 8.3 G'S.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
IN-FLIGHT PLANNING/DECISION..IMPROPER..PILOT IN COMMAND
OVERCONFIDENCE IN AIRCRAFT'S ABILITY..PILOT IN COMMAND
AIRSPEED..EXCEEDED..PILOT IN COMMAND
WING..OVERLOAD
DESIGN STRESS LIMITS OF AIRCRAFT..EXCEEDED..PILOT IN COMMAND


Contributing Factors

WING..FAILURE,TOTAL
WING..SEPARATION

HotelBushranger
05-11-2006, 07:54 AM
Thank you for this, I guess proves not all planes are ment to by flown like you want it to.

p-11.cAce
05-11-2006, 09:02 AM
Its funny how often in "hangar flying" sessions you hear all the tales of pushing the envelope - the reality is anytime you operate outside the pilots operating handbook limitations you have become a test pilot. Aircraft are unbelievable safe but the limitations exist for a reason.

FatBoyHK
05-11-2006, 10:52 AM
its elevator must be overmodelled BIG time...

msalama
05-11-2006, 11:51 AM
OMFG http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif What a c**ppy way to die, even if the pilot is the one to blame here! Poor aircrew http://forums.ubi.com/images/smilies/16x16_smiley-sad.gif

PS. I'm sure you understand that the sig only applies to IL-2, of course...

Megile_
05-11-2006, 12:06 PM
That is possibly the second most surreal thing I have ever seen.

Sergio_101
05-11-2006, 06:12 PM
I watched the tape several times.
There is indeed a rapid change of AOA
immediately before the wings seperated.
Pilot got too agressive.

There are old pilots.
There are bold pilots.
There are NO old bold pilots.

Sergio

WTE_Galway
05-11-2006, 07:39 PM
From a poster at an old aero club I used to hang out at:

A superior pilot uses his superior judgement and knowledge to avoid ever entering a situation where his superior skills and abilities will ever be needed.

BfHeFwMe
05-11-2006, 09:34 PM
Well, at least it held up much stronger than a 4.01 Mustang.

SATAN_23rd
05-11-2006, 10:23 PM
Wow, that guy just proved Darwin right.

Gibbage1
05-11-2006, 10:55 PM
I dont mean to be insensitive, but I dont feel bad for the pilot. I feel bad for the pilots family, and anyone the aircraft landed on. He did something very stupid, and paid the ultimate price.

If I see a video of some young kid doing stunts on a motorcycle and eat it, I think "what a moron". The same thing should apply to any vehicle and any outcome. That aircraft was clearly not certified for it, and the pilot was clearly not. Im just hoping he did not take anyone with him.

msalama
05-11-2006, 11:09 PM
He did something very stupid, and paid the ultimate price.

Oh, definitely. No-one to blame but the guy. But still, put yourself in his place - what a f3kkin' way to die, I say again http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

major_setback
05-12-2006, 04:32 AM
I think he realized his mistake...too late.
I wonder what his last words would have been?

OberUberWurst
05-12-2006, 05:18 AM
Originally posted by major_setback:
I wonder what his last words would have been?

OHH NO!!! No BoB for me..

Xiolablu3
05-12-2006, 05:32 AM
Nasty crash.

I'm with you guys, I think he just pushed the aircraft too far.

Musy have been flying along and yanked the elevator hard, resulting in a massive shock to the wings.

Does look strange how he isnt turning at the time it happens tho, you would think just the elevators would snap off, not the wings.

ploughman
05-12-2006, 05:45 AM
As the aircraft falls you can see that the tail section has sufferred severe structural damage too. This might've occurred as a result of forces introduced after the wings snapped or maybe even in conjunction with the wing snap. Not sure. I only read the NTSB snippets posted above and I don't think they mention the failure of the tail section as being a contributor.

To bad for the guy though, even if it was all his own doing. It's not like it was malicious, just stoopid.

DuxCorvan
05-12-2006, 06:26 AM
Originally posted by Ploughman:
As the aircraft falls you can see that the tail section has sufferred severe structural damage too. This might've occurred as a result of forces introduced after the wings snapped or maybe even in conjunction with the wing snap.

After seeing it several times, it looks to me that the wings just hit the tail section immediatly after twisting towards fuselage and detaching. There's a cloud of lost fuel and parts concealing the area in the failure moment, so it can't be seen clearly.

Poor guy. He made a temerary move in an unproper vehicle, that's all.