Originally Posted by
A Squared
This is what I'm having difficulty wrapping my mind around. How do you (in daylight, VFR conditions) not notice that the airplane you're piloting is on a trajectory to crash a half mile short of the runway?
I'll take a stab at it, at the risk of invoking armchair psychology borne from my flight instructing background. I think that people react to unusual and/or sudden situations not by rational analysis (which if employed in these 2 cases would have said "Whoa, we're flying at the ground. Let's fly at the runway or the sky instead. And let's do so by making the appropriate pitch and power inputs.") but by gut-level reactions that are akin to instinctive reflexes. Or, a "comfort zone" if you will, of what actions will be taken. You'll always run to your comfort zone. Like that if something suddenly flies at your face, you'll blink. Now that's biological, and the aeronautical reflexes I'm talking about are not; but they're trained-in to a level where they might as well be. Like if you're driving a car and it starts drifting left, you'll automatically correct to the right without even thinking about it.
Well the problem comes in with
what is "trained in." And in flying, that comes in from your daily habits. For someone who's mostly done manual flying, (especially if it involves readily taking the controls over from another guy who's going out of bounds) that involves... manual flying. Seeing if the airplane is where you want it to be, and if not, putting it there. That is trained in. That's the comfort zone. So for someone of that background (or at least, recently) when the autopilot starts doing something other than what's intended, he will readily take over with the red button on the yoke (as he has, a multitude of times taken over from students) and put the airplane where he wants it.
Instead, for someone who flies purely with the automatics (due to whatever combination of SOP, company culture, personal background, etc.) it is trained in that any deviation from what's desired, is corrected by manipulation of the automatics. If a startling situation comes up, the gut-level comfort zone they run to won't be to fly the airplane (since that doesn't exist for them as a comfort zone) but rather to do a quick sequence of button pushes and knob twists to get the mode and values in the right place... just what they've been doing, in regular flight, every day for years or decades.
Now, this may work as intended, but it may also not. Because unlike manual flight, there can be quite a bit of logic involved in what modes are active and how the airplane is going to behave in reality vs. what's expected. So the sequence of button pushes and knob twists may not work; and now that the airplane is even closer to crashing, the pilot is getting panicky and even more tunnel visioned, and his next reaction is even likelier to be constrained to the gut-level comfort zone of a further flurry of button pushes and knob twists. If the pilot is automation dependent and has no confidence in his manual flying (and the fig leaf of the box checked in the sim 6 months ago will not provide that) then it will be difficult to impossible to break out of that loop and push the red button. I've seen exactly this in the sim, and it is scary.
http://lessonslearned.faa.gov/Indian...t%20Report.pdf
This is the accident report, and here is the relevant part of the CVR transcript:
25.9 to
24.8
304.8 to
306.6 CM2 (You are) descending on idle
open descent ah all this time
22.7 308.7 CM2 You want the FDs off now
21.4 310 CM1 Yeah
19.7 311.7 CM1 Ok, I already put it off
17.9 313.5 CM2 But you did not put off mine
14.8 316.6 Two Hundred
10.7 320.7 CM2 You are on the auto pilot still?
8.4 323 CM2 It's off
7.35 to
6.6
324.5 to
324.8 CM1 Hey, we are going down
6 325.4 One hundred rate
3.9 327.5 Sink rate
3.6 327.8 Chime
2.3 329.0 Sink rate 30
0.6 330.8 Sink rate 10
0 331.4 Crash sounds begin
I can't paste it in a way that the formatting isn't munged up, but the series of numbers that starts at 25.9 and counts down is seconds to impact. So at 25 seconds they realize that something is wrong, and that's actually a long time! Start a 25 second timer right now and sit on your hands, and see what it feels like. They had that much time to push the red button and fly the airplane away from the ground...
had they had the confidence in their flying and the fortitude to make the decision. On a VFR day! But instead they proceeded to try to untangle the automation settings and convince the airplane to do it itself.