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T-28 crash Hungary airshow

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T-28 crash Hungary airshow

Old 13th Sep 2023, 20:50
  #21 (permalink)  
 
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Originally Posted by GeeRam
Yep, ex-Marine pilot on another forum reckoned a min of 20deg pitch up required.

He said, he's been backseating in a 28 during practice at altitude with an airforce pilot doing the same thing, and an only 5deg pitch up saw a 800ft altitude loss as a result.....

Starting the roll with 5 degrees pitchup if he did not sustain in pitch (With forward stick to unload) while inverted definitely altitude loss is a factor to consider

However the more I look at the video the more it looks like past inverted around 200 to 220 degrees into the maneuver there is an interruption in roll which i deem to be main contributing factor followed by a pull on the yoke until impact.


There is zero error margin when performing aerobatic maneuvers at low altitude.
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Old 14th Sep 2023, 10:58
  #22 (permalink)  
 
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Here we have a clip showing same aircraft and same pilot doing the same maneuver before properly executed throughout, at the same height with very little bank nose up at the outset practically on axis.
So both pilot and aircraft were capable of such a maneuver.

https://www.facebook.com/SzegedTV/videos/1493286841469016

https://www.facebook.com/SzegedTV/videos/1493286841469016

Last edited by markkal; 14th Sep 2023 at 11:08.
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Old 14th Sep 2023, 11:01
  #23 (permalink)  
 
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I'm intrigued by the brief roll reversal just before impact
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Old 14th Sep 2023, 11:34
  #24 (permalink)  
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Originally Posted by 212man
I'm intrigued by the brief roll reversal just before impact
High speed stall perhaps?

T-6 will flick the other way if pulled hard enough in a turn I believe - saw it occur high over Arundel once from underneath, steep left hand turn getting tighter, sudden snap into a steep right turn, I imagine probably a demo by instructor.
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Old 14th Sep 2023, 14:01
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Originally Posted by 212man
I'm intrigued by the brief roll reversal just before impact
I see no such thing?
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Old 14th Sep 2023, 14:52
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Originally Posted by Vessbot
I see no such thing?
It is there, very shortly before the crash, best seen in this "video":
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Old 14th Sep 2023, 14:58
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Originally Posted by sablatnic
It is there, very shortly before the crash, best seen in this "video": https://www.youtube.com/shorts/oTMM_MO1J2E
Oof... yikes. Yeah, accelerated stall while they're pulling for dear life certainly explains it.
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Old 14th Sep 2023, 21:39
  #28 (permalink)  
 
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Originally Posted by 212man
I'm intrigued by the brief roll reversal just before impact
I'd wondered about that too. Given what subsequently occurred my thought was that perhaps, selflessly, the pilot had spotted their trajectory could hit someone on the ground and attempted to manoeuvre away in the last few seconds.

FP.
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Old 15th Sep 2023, 08:47
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Originally Posted by Vessbot
Oof... yikes. Yeah, accelerated stall while they're pulling for dear life certainly explains it.

Definitely dynamic stall, a reflex to pull hard on the stick to get away from approaching ground.
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Old 15th Sep 2023, 13:26
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Originally Posted by markkal
Definitely dynamic stall, a reflex to pull hard on the stick to get away from approaching ground.
That was my thought as well. It seemed like the maneuver could have been completed if not for that pull while inverted. Started off small but then some panic when it was apparent there was no recovery.
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Old 15th Sep 2023, 14:30
  #31 (permalink)  
 
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Roll rate on pull-up was about 36*/sec,; roll rate from inverted,nose below horizon was only about 24*/sec;;the only recovery from the highest point,about 550`agl was a brisk roll,and no pull...

`Zero Error Margin` is a book written by Col. Des Barker SAAF about 20 yrs ago,which goes into all about Airshows/Air Displays...It is difficult to find copies,but can be downloaded off Google...
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Old 15th Sep 2023, 19:49
  #32 (permalink)  
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Some more thread drift today....

`Zero Error Margin` is a book written by Col. Des Barker SAAF about 20 yrs ago,which goes into all about Airshows/Air Displays...It is difficult to find copies,but can be downloaded off Google...
I attended a flight test session presented by Des a number of years ago, the theme being: You're the company test pilot, they're going to tell you to demonstrate the plane at an airshow, these are some things you should know..... An excellent presentation! Des occasionally flew a unique GA type in South Africa, which was quite similar to the plane I own, we had quite a chat about it. Sadly, he was killed flying it a few years back.
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Old 15th Sep 2023, 20:48
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Originally Posted by sycamore
Roll rate on pull-up was about 36*/sec,; roll rate from inverted,nose below horizon was only about 24*/sec;;the only recovery from the highest point,about 550`agl was a brisk roll,and no pull...

`Zero Error Margin` is a book written by Col. Des Barker SAAF about 20 yrs ago,which goes into all about Airshows/Air Displays...It is difficult to find copies,but can be downloaded off Google...
Great book, It deserves to be read !!!!
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Old 16th Sep 2023, 08:36
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Is it conceivable that he pushed forward too much inverted and approached an inverted stall?
i ask this as Iíve found myself inverted on three occasions when the aircraft didnít do what I expected.
My first was in a Victor air tourer out of Sunderland in the 70s attempting to demonstration to my brother a loop and the aircraft descended on its back which I only managed to exit with rudder and aileron.(my 5 hours aerobatic training on a chipmunk reverted to forced landings as my instructor was petrified teaching Aeros).
My second was my first attempt at a slow roll from 1,000ft in a glider when the roll rate reduced to zero. Realising that I was in a stable inverted stall from pushing too hard I converted to the last half of a loop, conscious that there might be a conflict with VNE and having been told that to avoid that pull hard to destroy energy I pulled with the G meter pegged at 6.
My third was in a Grob teaching the french art of mountain soaring on a slope with an escape route out of the Cape gliding club adjacent to the local quarry when a loud bang found us inverted at 200ft whilst flying figures of eight in lift surges. Recovery was stick neutral..allow nose to drop, speed to build and roll out.
of course I could be writing twaddle
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Old 16th Sep 2023, 10:43
  #35 (permalink)  
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Originally Posted by blind pew
Is it conceivable that he pushed forward too much inverted and approached an inverted stall?
i ask this as Iíve found myself inverted on three occasions when the aircraft didnít do what I expected.
My first was in a Victor air tourer out of Sunderland in the 70s attempting to demonstration to my brother a loop and the aircraft descended on its back which I only managed to exit with rudder and aileron.(my 5 hours aerobatic training on a chipmunk reverted to forced landings as my instructor was petrified teaching Aeros).
My second was my first attempt at a slow roll from 1,000ft in a glider when the roll rate reduced to zero. Realising that I was in a stable inverted stall from pushing too hard I converted to the last half of a loop, conscious that there might be a conflict with VNE and having been told that to avoid that pull hard to destroy energy I pulled with the G meter pegged at 6.
My third was in a Grob teaching the french art of mountain soaring on a slope with an escape route out of the Cape gliding club adjacent to the local quarry when a loud bang found us inverted at 200ft whilst flying figures of eight in lift surges. Recovery was stick neutral..allow nose to drop, speed to build and roll out.
of course I could be writing twaddle
I don't think I fancy flying with you.
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Old 16th Sep 2023, 13:06
  #36 (permalink)  
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Originally Posted by blind pew
Is it conceivable that he pushed forward too much inverted and approached an inverted stall?
i ask this as Iíve found myself inverted on three occasions when the aircraft didnít do what I expected.
My first was in a Victor air tourer out of Sunderland in the 70s attempting to demonstration to my brother a loop and the aircraft descended on its back which I only managed to exit with rudder and aileron.(my 5 hours aerobatic training on a chipmunk reverted to forced landings as my instructor was petrified teaching Aeros).
My second was my first attempt at a slow roll from 1,000ft in a glider when the roll rate reduced to zero. Realising that I was in a stable inverted stall from pushing too hard I converted to the last half of a loop, conscious that there might be a conflict with VNE and having been told that to avoid that pull hard to destroy energy I pulled with the G meter pegged at 6.
My third was in a Grob teaching the french art of mountain soaring on a slope with an escape route out of the Cape gliding club adjacent to the local quarry when a loud bang found us inverted at 200ft whilst flying figures of eight in lift surges. Recovery was stick neutral..allow nose to drop, speed to build and roll out.
of course I could be writing twaddle

nope. The images do not support a push inverted to the extent that a negative g stall would occur. The trajectory supports a low g case but not significantly negative, so, no stall at that point.
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