PPRuNe Forums - View Single Post - Boeing incidents/accidents due to Thrust/Pitch mode mishandling
Old 12th Oct 2018, 19:37
  #46 (permalink)  
hans brinker
 
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Originally Posted by KRviator
Respectfully, I think you've both missed the point. I guess you would both argue that AF447 was solely the result of the crew, rather than the fact they lost the airspeed in the first place...

Yes, the crew screwed up (in both AMS and AF447...), in a massive way. I am not disputing that fact at all, nor trying to absolve them of that claim.

But...

Amsterdam was not, in itself, the fault of mode confusion, or automation dependency. The crew recognised the decaying speed, and that the throttles retarded automatically. They then pushed them up, and believed (and this is where their lack of systems understanding failed them) they would stay there - and through lack of basic airmanship, let the speed decay to a point where the accident was inevitable.

Consider the case of Scandinavian 751. Engine surge on the initial climb, pilot does the right thing and reduces power. But the autothrottle restored power on the engine, resulting in dual engine failure and the ensuing crash. The pilot knew nothing about that 'feature', nor did the airline. Is it still their fault for not noticing the increasing power? The moral of the story is, pilots screwup certainly. But rarely does that, in itself, cause an accident and it is fatally simplistic to simply lay the blame for a prang at the feet of the crew.
I fly the A 320, quite a few years ago as a first year fo, in a turn to final, I got the “speed, speed, speed” warning. Unsure of how to proceed, I looked to the left. He said “my controls”, realized the automation wasn’t aware we were trying to land, and said “your controls if you want them “. The speed warning is there to tell you your energy is decreasing, which is what I was trying to do. It took a good long read of the manual after landing to realize why it happened. Shortly after my upgrade I flew a few times with the autothust deferred, and I realized I had gotten very used to it working, so I made it a point to not use it on both TO and landing whenever possible. There seems to be a lot of companies/authorities that feel keeping the automation on the highest level is always preferred. Luckily for me, my company feels proficiency is important. When I say the pilots were at fault, it is part of a bigger problem. If the company/authorities won’t let the pilots fly manual it might prevent some accidents, but it will definitely cause other accidents. Having said all that:
AF 447, the only instrument that failed was airspeed, and only for the first minute. The second officer kept pulling back even after being told not to by the FO. The FO never took control when he clearly should have. For the record, I hate the Airbus design, you really can’t see what your colleague is doing.
AMS, the throttle moved back RIGHT AFTER THE FO MOVED THEM UP, the training captain should have recognized the automation wasn’t going to work.
I haven’t read the whole report on SAS, but it sounds similar, he pulled power, power came back up, he did nothing.
As pilots we are the last line of defense against all the deficiencies in airplane design, SOPs, rules, ATC errors, etc.. does that mean we are always the problem? No, but we need to be able to recognize, react and recover when something goes wrong. Failing to do so will get you killed, and criticized on pprune afterwards.
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