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-   -   AA757 Near Stall - Recovery Caused Injuries (https://www.pprune.org/rumours-news/646609-aa757-near-stall-recovery-caused-injuries.html)

hans brinker 12th May 2022 15:54

Interesting that the pilot with 1009 hours TT was the telling the pilot with13.000 hours in type what to do.

Chronic Snoozer 13th May 2022 01:30

Sounds like your beloved startle factor at play, Uplinker. :}

BoeingDriver99 13th May 2022 01:47

I think that it took four years to produce this report as bordering on negligence. All FDR/CVR, pilots survived intact and an investigation with something to learn from it couldn't be produced in a few weeks/months?

And yes we are in a parallel universe where pilots cannot pilot anymore.

Bksmithca 13th May 2022 03:35


Originally Posted by hans brinker (Post 11229237)
Interesting that the pilot with 1009 hours TT was the telling the pilot with13.000 hours in type what to do.

As a flight engineer I needed to be type rated for the aircraft I was working, same with the pilots but why would the flight instructor not need to be type rated?

WideScreen 13th May 2022 06:04


Originally Posted by BoeingDriver99 (Post 11229484)
I think that it took four years to produce this report as bordering on negligence. All FDR/CVR, pilots survived intact and an investigation with something to learn from it couldn't be produced in a few weeks/months?

Looks to me, it was clear WHAT happened, though pretty unclear WHY this happened. As raised, that a 13k hours highly experienced pilot started to garble up and needed to be corrected by a young one. And, I still don't see a clear answer to that.

Originally Posted by BoeingDriver99 (Post 11229484)
And yes we are in a parallel universe where pilots cannot pilot anymore.

Yep. This is not the first time, and it gives me the impression, that 2 things are happening:
A) An overload of regulations/must-do's, with the consequence that things start falling off the table.
B) More and more an emphasis on "regulations and must-do's", with the consequence, that pilots become hesitating to "follow their guts" to solve an issue.

This not so much being a flying industry only issue. It happens everywhere, that people no longer dare to solve an issue, but revert to "not in my playbook, so I don't (or I am not allowed to) do".

An example of what happened some years ago in GA, with a C172, a highly experienced pilot. Flying at 2000ft towards a controlled airport, clouds come in unexpectedly with heavy winds and the aircraft getting "VFR on top". The airport was still visible in perfect VFR weather. So, the best option would have been, stay VFR on top, IE fly higher than the normal height for the VFR route in the controlled airspace to the airport. But, that implies, asking permission, and investigations, and potentially a fine. The pilot decided to descent through IMC to expected VDR weather below the clouds. Unfortunately, the clouds were fog, all the way to the ground and the aircraft did a CFIT (and, explicitly, no Loss of Control). 4 People dead, just because the pilot selected to do what could not be registered as an offense and avoiding getting asked nasty questions, etc.


viking767 13th May 2022 08:18

The 1009 hour figure is obviously an error. The relief pilot is required to have an ATPL with a 757/767 type rating,

Chronic Snoozer 13th May 2022 12:01


Originally Posted by WideScreen (Post 11229530)
A) An overload of regulations/must-do's, with the consequence that things start falling off the table.
B) More and more an emphasis on "regulations and must-do's", with the consequence, that pilots become hesitating to "follow their guts" to solve an issue.

This. Lawyers and managers in cockpits.

alf5071h 13th May 2022 14:24

This thread is an example of how language can frame issues, biasing opinion, leading inappropriate conclusions.
The thread title ‘757 Near Stall’ does not relate to the safety investigation referring to speed monitoring.
Total flight hours is falsely equated to experience, whereas experience relates to prior exposure to a situation or similar, and embedding that in memory with focussed learning, understanding and relevance.

The outcome of this event was success; a safe landing. The safety issue is with speed awareness and subsequent flight handling.
Previous incidents and more general speed-AT issues suggests some auto-flight complacency. If repeated events are specific to an aircraft type then consider the technology - dated certification, assess if this is compatible with modern environment, training; consider modification. Crews cannot be expected to manage every system weaknesses in every situation, all of the time.

Re recovery; with situation recognition the injuries resulted from aggressive control. With hindsight this maybe judged inappropriate, but the reaction could have been ingrained by training and SOPs requiring urgent aggressive response to low speed or upset events. The point at which the stall / upset recovery no longer applies has to be judged by the crew, but without alternative other than to ‘fly the aircraft’. Judgements are relative, they are not clearcut decisions defined by procedure, and thus should not be criticised after the event. The crew acted as they saw the situation and as required by their recall of training; the points of safety involve what contributed to the situation and crew behaviour.

[For further debate, would a correct, aggressive upset recovery from wake turbulence, with cabin injury, be assessed in the same manner.]

If the satisfaction of blame is still required then consider how crews are trained for unexpected situations, how they are expected to manage technological deficiencies - situations which have probably been seen by others beforehand, but not reported. A professional approach seeks perfection, but rarely acknowledges the human limitation, that we have done our best but circumstance outwitted us.

vilas 13th May 2022 15:53

This incident has two straight forward reasons. First is ignorance of the the not so smart or perhaps not very necessary THR HOLD function. And second is lack of proper instrument scan. Speed and altitude requires frequent look over whether with or without AP. A320 accident in 1980 Bangalore is simply mirror reflection of the SFO. Airbus ATHR is non moving thrust levers while B777 has tactile feed back through moving throttles but failed to notice that they were at idle all along. Both accidents nobody monitored FMA or speed. In Bangalore speed reached 26kts below Vapp, in SFO it reached 31kts below Vapp. with similar results.

Axerock 13th May 2022 16:46

Based on the move of the Tibet A-319 postings - Shouldnt this be moved to the Non airlines / accidents and close calls forum as well?

alf5071h 13th May 2022 17:37

vilas,
First how can you explain knowledge of the extent or quality of the crews ‘ignorance’.
Unlikely, pure speculation based on your assessment of the event with hindsight. False reasoning from the outcome, backward to deduce cause … Not so.

How many similar events have been encountered without a problem.

Second, how can you know the quality of the crews instrument scan; presuming that you were not there nor have discussed the issue with the crew.

Hindsight bias; https://thedecisionlab.com/biases/hindsight-bias
Individual effects -
… If we look back at past decisions and conclude that their consequences were indeed known to us at the time (when they weren’t), then it makes sense that we will overestimate our ability to foresee the implications of our future decisions. This can be dangerous, as our overconfidence may lead us to take unnecessary risks. …


Also see the related biases: Regret Aversion, Cognitive Dissonance, Dunning–Kruger Effect

tdracer 13th May 2022 17:58


Originally Posted by sherburn2LA (Post 11228372)
I am wondering about the parallel universe where 186 kts is a dangerously low airspeed requiring aggressive intervention

I've been wondering the same - 186 kts doesn't sound dangerously slow to me. More like the PF was distracted then startled when he realized they were approaching stall and shoved the wheel forward.
Did they get a stick-shaker, or did the pilot just realize they were going way to slow?

vilas 14th May 2022 05:34


Originally Posted by alf5071h (Post 11229833)
vilas,
First how can you explain knowledge of the extent or quality of the crews ‘ignorance’.
Unlikely, pure speculation based on your assessment of the event with hindsight. False reasoning from the outcome, backward to deduce cause … Not so.

How many similar events have been encountered without a problem.

Second, how can you know the quality of the crews instrument scan; presuming that you were not there nor have discussed the issue with the crew.

Hindsight bias; https://thedecisionlab.com/biases/hindsight-bias
Individual effects -
… If we look back at past decisions and conclude that their consequences were indeed known to us at the time (when they weren’t), then it makes sense that we will overestimate our ability to foresee the implications of our future decisions. This can be dangerous, as our overconfidence may lead us to take unnecessary risks. …


Also see the related biases: Regret Aversion, Cognitive Dissonance, Dunning–Kruger Effect

Look if you make an approach without looking at your speed till you crash it's poor flying. It's poor scan. Period. No fancy theories are required. FIrst pilot of Boeing should know the intricacies of THR HOLD. There's a problem in SFO report NTSB asked Boeing to look at it. However it's a case of thrust not moving to maintain speed notwithstanding why. So if the pilot has the scan he will notice and move the thrust himself. Providing fancy human factors for poor flying is the reason for more and more automation. Finally it will take the pilot out.

hans brinker 14th May 2022 05:41


Originally Posted by tdracer (Post 11229840)
I've been wondering the same - 186 kts doesn't sound dangerously slow to me. More like the PF was distracted then startled when he realized they were approaching stall and shoved the wheel forward.
Did they get a stick-shaker, or did the pilot just realize they were going way to slow?

Regardless if it was dangerous, the crew selected an airspeed of 250. For the aircraft to reach a speed of 186 means a loss of 64 kts IAS that wasn't noticed or corrected.
That's a safety issue.

BoeingDriver99 14th May 2022 07:19

Whilst I think Alf understands the complexity behind the human condition better than most; vilas has a simple but correct point - if Speed decays 20-30 knots below Vapp then either the pilots are not scanning/observing the speed or they are and don't comprehend the situation.

One is closer to negligent behaviour and more straightforward and the other is much more complex and involves training, recruitment, fatigue, SOPs, CRM and so on.... So it really then depends on where you place the crew in any incident on that scale and more importantly where their management places them.

DType 14th May 2022 07:30

Awfully sorry, SLF here (though I have flown in Vampires and Meteors), but it sounds like another case where highlighting AoA would have helped?

SpamCanDriver 14th May 2022 08:56


Originally Posted by DType (Post 11230034)
Awfully sorry, SLF here (though I have flown in Vampires and Meteors), but it sounds like another case where highlighting AoA would have helped?

The problem was caused by a lack of monitoring the instruments, specifically the Airspeed indicator.
I'm not sure how adding another instrument to the panel would of solved the problem

Uplinker 14th May 2022 10:54

Agree. A lack of instrument scan, simple as that. Pilot 101.

This crew obviously did not monitor their airspeed. Had they noticed the decaying speed, all they had to do in a Boeing - in any aircraft for that matter - was manually push the thrust levers forwards.

If the speed starts dropping, I glance at the engine N1 or EPRs, and I expect to see the auto-thrust bring the engines up to correct it. If auto-thrust doesn't react I do something about it.

If the automatics are not doing what is required, you step in and reselect or take over.

Unless, maybe the thrust levers both became physically jammed at idle and both crew struggled to release them as the speed decayed, but we haven't heard anything along these lines.

42go 14th May 2022 13:28

For all the grand science, Alf, it is called 'cock-up' by pilots.

tdracer 14th May 2022 19:42


Originally Posted by hans brinker (Post 11230011)
Regardless if it was dangerous, the crew selected an airspeed of 250. For the aircraft to reach a speed of 186 means a loss of 64 kts IAS that wasn't noticed or corrected.
That's a safety issue.

You're missing my point. Not in any way excusing allowing airspeed to drop 64 kts before taking action - just wondering why that action was so aggressive that it injured people in the back - flinging the flight attendants into the ceiling.
Seems a gentle forward push along with advancing the thrust levers would have been more than sufficient to prevent the aircraft falling out of the sky.


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