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-   -   White Waltham Pitts crash (https://www.pprune.org/accidents-close-calls/624916-white-waltham-pitts-crash.html)

rnzoli 25th Sep 2019 10:58


Originally Posted by Akrapovic (Post 10564957)
Iím guessing due to the nature of the operation (training/pleasure flights etc), there would be camera footage?

Don't have too high hopes, sometimes even with in-cockpit footage, there is no answer to the "why"s.
Recently I had the chance to look at stills from an in-cockpit camera prior to a fatal crash, killing 2 experienced FLIGHT INSTRUCTORS. All you can see is that after a touch-and-go, on the turn from crosswind-to-downwind leg, the aircraft banked right normally first, then overbanked and started to point its nose down, and then suddenly the pilot flying pulled the stick and extreme left, causing a textbook accelerated stall.
For several seconds, the aircraft continued to roll right and nose down, with no change in control inputs. Even when nearly inverted, the accelerometer showed 2 Gs, and the turn coordinator exhibited the textbook signs of spinning. The last still frame showed the place where they would hit a few more seconds later.

There was no sound, no boody scenes, but about 60 of us was speechless for a while. What can make 2 experienced people make this basic mistake? We don't know. Perhaps something caught their attention too much, and the airplane was light, easy to stall with sudden control inputs. We will never know, what went on in their heads, what did they think, despite the camera footage.

Akrapovic 25th Sep 2019 13:22


Originally Posted by rnzoli (Post 10579081)
Don't have too high hopes, sometimes even with in-cockpit footage, there is no answer to the "why"s.
Recently I had the chance to look at stills from an in-cockpit camera prior to a fatal crash, killing 2 experienced FLIGHT INSTRUCTORS. All you can see is that after a touch-and-go, on the turn from crosswind-to-downwind leg, the aircraft banked right normally first, then overbanked and started to point its nose down, and then suddenly the pilot flying pulled the stick and extreme left, causing a textbook accelerated stall.
For several seconds, the aircraft continued to roll right and nose down, with no change in control inputs. Even when nearly inverted, the accelerometer showed 2 Gs, and the turn coordinator exhibited the textbook signs of spinning. The last still frame showed the place where they would hit a few more seconds later.

There was no sound, no boody scenes, but about 60 of us was speechless for a while. What can make 2 experienced people make this basic mistake? We don't know. Perhaps something caught their attention too much, and the airplane was light, easy to stall with sudden control inputs. We will never know, what went on in their heads, what did they think, despite the camera footage.

Of course, but you would agree that an answer to the 'how's', is certainly better than no answer at all? A lot can be gleaned from footage and there are numerous examples of aircraft accidents where footage provided to the authorities has assisted a great deal in concluding the cause of the accident.

Genghis the Engineer 25th Sep 2019 17:29

Remember - whilst it satisfies our curiosity, it IS NOT the objective of an air accident investigation to explain an accident.

It is the objective to provide recommendations to anybody who can use them, as to how to prevent future accidents.

That can often be done without fully understanding the accident mechanism itself.

G

markkal 25th Sep 2019 21:27

Perhaps out of topic but to answer Akrapovic in his specific detailed description of loss of control accident caught on camera, I would think in this particular scenario, there is a precise answer as "As to why", and this is wrong imputs to correct an overbank with nose dropping, whatever the cause of that overbank..

This is due to lack of specific training from flight instructors, whom are certainly fully qualified for normal operations have often no clue of how to recover from a degrading unusual attitude situation, such as this one. They applied the wrong inputs relying on deadly intuitive inappropriate instincs trying to raise the falling wing with opposite aileron and pulled on the elevator at the sight of approaching ground.

One should view slow flight below the second regime / stall / spin as another flight regime with its own rules and techniques, one can easily make an analogy with driving on snow and ice which likewise has its own rules and techniques, both anti instinctive as in the former LOC flying scenario.

When loss of control happens while driving on dry pavement with a contemporary vehicle ( Old rear wheel drive vehicles without computerised electronic stability assistance are different ) the reflex is to release the throttle pedal and hit the brakes, which is essentially correct. But in icy slippery conditions the worse thing to do is to reduce throttle pedal and hit the brakes.

Likewise during a stall / incipient spin scenario like the one above, the worse reaction is to apply opposite aileron- in a situation of aileron reversal- to lift a dropping wing and pull on the stick leading to a flick. Whether the situation was recoverable or not due to suficient height I don't know, but control inputs were utterly wrong.

Unless they had some technical or other issues leading to the upset, what was lacking for a safe outcome was early recognition of the degrading situation followed by wrong recovery inputs when it was already too late. However typical 1000 ft agl height in the traffic pattern allows for immediate recovery like in 1/8th of a turn if the correct reflexes and appropriate inputs are applied.

Like taking a course and practicing active skid / brake / throttle control on an snowy track with your vehicle, indulging in uprt-loc advanced aircraft control training saves lives.

As far as the Pitts accident at White Waltham is concerned, instructor was duly qŻalified and used to those maneuvers, I would rule out loss on control..Something else must have happened RIP

PickyPerkins 26th Sep 2019 01:16


Originally Posted by rnzoli (Post 10579081)
. ... What can make 2 experienced people make this basic mistake? ... We will never know, what went on in their heads ...

Could "what went on in their heads" be what was described 75 years ago by Langewiesche in "Stick and Rudder"?

[QUOTE] Unfortunately, as the airplane drops out from under the pilot and as its nose dips earthward, the pilotís "instinctive" reaction will be to haul back all the harder on the stick. If his imagination works with faulty images, if he imagines that the stick is the airplanes up-and-down control, he can hardly help hauling back on the stick. This instinctive reaction will be especially impulsive and uncontrollable if the pilot has failed to sense the coming of the stall, and the stall takes him by surprise.

And that is the real danger of stalling: this faulty reaction to the stall, rather than the stall itself. It is quite rare that a pilot is killed simply because he stalled. But it happens with tragic monotony that a pilot is killed because, stalled when he did not expect it, he either fails to recognize the stall for what it is, or fails to control that impulsive desire to haul back on the stick: he clamps the stick back against his stomach in a terrified cramplike effort to hold the airplane up, and thereby makes the stall worse or converts it into a spin. [END QUOTE]

The "tragic monotony" continues to this day.

rnzoli 26th Sep 2019 06:32


Originally Posted by PickyPerkins (Post 10579668)
Could "what went on in their heads" be what was described 75 years ago by Langewiesche in "Stick and Rudder"?

Yeah, that's it!
Some older guys told me: if I get an unpleasant surprise flying, just sit on my hands for a moment, in order to give my brain a little time to comprehend the situation, instead of doing something stupid right away. Of course, this is easier said than done. But this case also highlight, how unrealistic stall training is, when you stall with level wings, at the precisely expeced moment. Accelerated stalls are far more sinister.

Skycop 26th Sep 2019 16:56

Modern training seems to focus almost exclusively on stall and spin prevention and the thinking behind that has often been discussed.

However, the problem comes that once the stall/spin threshold has been breached, one also has to know how to recover.

Pilot DAR 26th Sep 2019 18:31


once the stall/spin threshold has been breached, one also has to know how to recover
I'm thinking that a pilot experienced in aerobatics in a Pitts is probably well past this point in skills development...

Gadget freak 27th Sep 2019 10:59


Originally Posted by Genghis the Engineer (Post 10579386)
Remember - whilst it satisfies our curiosity, it IS NOT the objective of an air accident investigation to explain an accident.

It is the objective to provide recommendations to anybody who can use them, as to how to prevent future accidents.

That can often be done without fully understanding the accident mechanism itself.

G

From the AAIB website.......
"Our purpose is to improve aviation safety by determining the circumstances and causes of air accidents and serious incidents, and promoting action to prevent reoccurrence."

Asturias56 25th Nov 2020 11:52

I see the AAIB Report is "out for consulation" now

SignalSquare 26th Nov 2020 19:46

Never knew AAIB reports went out for 'consultation'.
Is it a report or not?

Pilot DAR 26th Nov 2020 20:14

I have no knowledge of this event, but I have been a consultant on accident reports where I had been a participant in the investigation. It's like proof reading, the investigating agency likes to make sure that facts are right before it goes public.

AnotherRedWineThanks 30th Nov 2020 06:48


Why does the media insist on "stunts" instead of aerobatics or a similar more accurate word?
Sadly not confined to aviation. We only ever get "jabs" and never "injections". The media are lazy. Condolences to family and friends of pilot and passenger.

Genghis the Engineer 30th Nov 2020 21:21

IIRC AAIB normally once they're happy with what they've done, send a draft to any person or organisation "whose reputation may be affected", give them a month to respond, take account of any responses, then publish.

The people it goes out to may be regulators, manufacturers, owners, airfields, pilots, etc.

G

blind pew 1st Dec 2020 08:32

Was sent a preliminary report once but not in the UK..gave constructive criticism as none of those involved had ever been practiced the discipline and was immediately removed from the circulation list. Politics and not safety but didn’t surprise me.

J1N 1st Dec 2020 11:45

A process known as Maxwellisation: https://en.wikipedia.org/wiki/Maxwellisation

treadigraph 21st Jan 2021 13:52

Report published


During an aerobatics training flight, the aircraft struck the ground whilst in a spin. The aircraft was destroyed and both pilots were fatally injured. A definitive cause could not be determined, but it is likely that the commander became incapacitated during a spin and the student was unable to recover the aircraft in time.

Akrapovic 21st Jan 2021 15:02

Interesting, yet ultimately inconclusive, as is the case with a lot of GA accidents. . . .

ShyTorque 21st Jan 2021 17:25

There seem to be a number of similarities to another fatal accident that was possibly a very close call for myself.

Steen Skybolt G-BFHM crashed in August 1989, following loss of control, killing a friend of mine. I had spoken to him just before he departed and had helped him pull the aircraft out of the hangar. I owed him a beer and was waiting for him to return to the flying club. I voiced my concern to the CFI that darkness was approaching and there were no airfield lights. Very shortly afterwards the CFI received a phone call from the police....

I had promised to buy him a beer because he’d let me fly my aerobatic sequence in that aircraft on its previous flight. I had flown the aircraft from the (edit) front seat, the seat he died in. The cause was not positively determined but according to the other occupant (his badly injured girlfriend) the aircraft had fallen out of a stall turn she’d attempted and spun. She wasn’t able to recover and had handed over control. The pilot apparently called out that he thought she was obstructing the controls and the aircraft struck the ground still spinning. A pair of sunglasses and an AA battery were found loose in the wreckage and it was thought one of them might have been involved in a control jam.

Having said that, it was only after the report came out that I realised how few hours he had, less than 10% of my own yet he was happy to fly aerobatics from 1,000 feet. My own base height was three times that despite being an RAF QFI and in regular practice in both Aeros and spinning. Although he often flew aerobatics I have always wondered how often he’d practiced spin recoveries.

Asturias56 23rd Jan 2021 14:44

Problem seems to have been ta possible combination of sudden incapacitation in an aeroplane that was out of CG limits and with only a limited amount of height to recover.

If they'd been further west they could have had an extra few thousand feet to play with; if they'd been with in limits the same seems to apply

What was odd was the small gadgets on the rudder cables (tho they don't think they had any effect) - strange that someone would modify them and not think they should be approved?


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