Originally Posted by deSitter
If computers are going to fly airplanes, then they must do so under complete command of the crew, and in a sudden control emergency, it is senseless to lack an instant "GIMME" switch, that turns the airplane into a very big stick-and-rudder platform.
a) computers do not fly airplanes until the captain decide it, on his own will, by setting up autopilot and autothrust.
b) even so, the captain do select his course, speed, flight level, etc., the computers do not. He is in full charge of the flight.
c) both autopilot and autothrust can maintain a safe flight, only if certain flight parameters are not exceeded.
d) at any time, the captain may decide to take over and revert to manual flight.
e) in manual flight, flight envelope protections do not "fly" the aircraft, neither do drive your car an ABS instead of you; if you still have some flight envelope protection working, then, there is no more reason to turn them off than to disconnect your ABS if you were on the edge of losing control of your car; once control is lost, you may kill yourself, but an ABS can also save you if you need to use your brakes more efficiently.
Originally Posted by deSitter
I have no doubt that in the end, we'll find out that the crew lost precious time trying to figure out what to do with the FMC
More likely, they will expect the aircraft to save itself and will forget to fly it, which is a very different issue.
Originally Posted by deSitter
or even as someone suggested earlier, put the AP back in charge when that was sure to lead to disaster.
a) this "someone" suggestion is very unlikely: autopilot can't re-engage until the flight parameters are restored to normal, neither ALTERNATE LAW (PROT LOST) would be changed back to NORMAL LAW (until after landing);
b) nonetheless, this end result would not be due to computers choice but to captain action; if captain think that airspeed is reliable when it is not, who is to blame?
c) can't you see the paradoxe: if one had to "fight" (like you said) with such computer, why would he give the computer its full control back in a hurry without even trying to fly his aircraft?
Originally Posted by deSitter
I have no idea why some professional aviators are so adamant, to the point of irrationality, in their defense of flight computers.
Or, why some professional aviators, relying on automatisms from day 1 in aviation history (mechanical, electrical, electronical,...) are so irrational when it comes to flight computers, to the point that they don't even try to understand how they work?
Originally Posted by deSitter
Perhaps it is the human need to feel "on top of the curve" and "up to snuff" with modernity. No one is arguing that FMCs are not a great idea for normal flight - but when it becomes an end in itself, something has gone off the rails.
Human machine interface, ergonomy and training are the main issues with current airliners. If one, for too long, is staying out of the loop (for irrational reasons against the systems or intellectual lazyness), he'll never be able to catch up with the machine of today.