3 ms·

I'm not saying I agree with the decision, just that you have to put it in context. It would be interesting to go back and see why they chose that design. Altho

by snom390 12y ago

I'm not saying I agree with the decision, just that you have to put it in context. It would be interesting to go back and see why they chose that design. Although the failure was basic, and they certainly lacked hands-on high altitude flying experience, you have to consider that the situation they got themselves into became very confusing, to the point where they likely didn't trust any instruments or warnings they got. The right initial reaction to the situation would _not_ have been to push the nose down, but to add power and a _slight_ nose up input. However, pulling back on the stick would have been safe to do in normal law, so I think it's very likely that the most inexperienced pilot thought he still had stall protection, and that combined with control inputs that would only be appropriate in lower speed settings caused the initial sequence of events.

mikeash 12y ago
I think the initial sequence of events is entirely understandable. Where it becomes completely ridiculous is when they're losing altitude at a rapid rate despite having the stick pulled all the way back. You are stalling. That should have been abundantly clear at that point. And then, when stalling, holding the stick back is the last thing you want to do. Given the confusion and sensor trouble, stalling the plane is understandable. Keeping it stalled all the way down to the ocean is what is crazy. Designing the control system so that one pilot can't even know that the other pilot is keeping the plane stalled is likewise crazy.
- snom390 12y ago
  It should have been abundantly clear, however it's not hard to imaging that if you're flying 99% of the time in an airplane that makes it _impossible_ to stall it (ie. pushing back all the way on the stick will not allow it to stall), you might be in a mindset where the possibility of a stall might not even enter your thought. The fact that the stall warning stopped due to low airspeed and came on again when they pushed the nose forward (because airspeeds became available again and the stall warning started working) only made the problem worse, and can explain why they completely lost the trust in the instruments. In the end, there's a host of factors and bad design decisions that led up to the accident, and on top of that poor high altitude training.
  - mikeash 12y ago
    That's why I blame a lack of training for the basics. If you can ever get to the point as a pilot where the possibility of a stall might not even enter your mind, you've become dangerous. If the planes don't enter that regime themselves, then it needs to be intentionally caused in training so they don't lose proficiency.
    - snom390 12y ago
      Agreed, and that was one of the recommendations in the report. AFAIK current commercial flight simulators aren't designed to accurately simulate the aircraft outside the normal flight envelope, so pilots can only simulate approach to stall, or a stall that might not accurately represent what will happen with an actual airplane, in contrast to the stall training you do in a light aircraft.

by snom390 12y ago

mikeash 12y ago

I think the initial sequence of events is entirely understandable. Where it becomes completely ridiculous is when they're losing altitude at a rapid rate despite having the stick pulled all the way back. You are stalling. That should have been abundantly clear at that point. And then, when stalling, holding the stick back is the last thing you want to do. Given the confusion and sensor trouble, stalling the plane is understandable. Keeping it stalled all the way down to the ocean is what is crazy. Designing the control system so that one pilot can't even know that the other pilot is keeping the plane stalled is likewise crazy.

snom390 12y ago
It should have been abundantly clear, however it's not hard to imaging that if you're flying 99% of the time in an airplane that makes it _impossible_ to stall it (ie. pushing back all the way on the stick will not allow it to stall), you might be in a mindset where the possibility of a stall might not even enter your thought. The fact that the stall warning stopped due to low airspeed and came on again when they pushed the nose forward (because airspeeds became available again and the stall warning started working) only made the problem worse, and can explain why they completely lost the trust in the instruments. In the end, there's a host of factors and bad design decisions that led up to the accident, and on top of that poor high altitude training.
- mikeash 12y ago
  That's why I blame a lack of training for the basics. If you can ever get to the point as a pilot where the possibility of a stall might not even enter your mind, you've become dangerous. If the planes don't enter that regime themselves, then it needs to be intentionally caused in training so they don't lose proficiency.
  - snom390 12y ago
    Agreed, and that was one of the recommendations in the report. AFAIK current commercial flight simulators aren't designed to accurately simulate the aircraft outside the normal flight envelope, so pilots can only simulate approach to stall, or a stall that might not accurately represent what will happen with an actual airplane, in contrast to the stall training you do in a light aircraft.