Originally Posted by
Australopithecus
It can happen in an Airbus too, btw. The first autopilot disconnect switch pressed and held overrides the opposite sidestick*. All of these features have to assume two rational, competent pilots. Its up to vetting, hiring and training to ensure that assumption remains valid
* Although, on edit, the Airbus architecture does allow for a subsequent dueling disconnect button fight..
"All of these features have to assume two rational, competent pilots."
I believe that is a problem. All designs assume "rational, competent pilots". But what is really a "rational, competent pilot"? Whenever something goes wrong, airplane makers are quick to blame the pilots. Presumably, because they didn't act "rationally and with competence". There are many examples, AF447, both MAC crashes etc.
However, I said it before and I'l say it again, there is no real measure of level of "rationality and competence". There is just a binary term, called "licensed pilot'. Since airplanes are meant to be flown by licensed pilots (whatever their level of competency is), either airplanes should be made such that any licensed pilot could safely fly them, or the license itself needs to be redefined and pass criteria should be severely stricter and should include reactions under stress (remember, the "rational" part). The question is, how does one test that without putting the candidate in real danger. Altough eliminating unsuitable candidates by darwin method would work quite well (and this forum is full of pilots so sure in themselves they would not mind to take such test), I'm not sure that's actually going to happen any time soon.
Going back to the design, the whole system is built around the premise of "2 rational, competent pilots". I believe it would be much more appropriate to require that the airplane must be able to fly safely with two parallel, independent systems in command. The fact that these systems are of biological nature should not play any role in the design.
Now just start thinking if the current cockpit design meets safety criteria. If it does, it should not matter if the "systems" in command are biological or not.
But the assumption that biological systems are flawless and the design can make shortcuts it would not with non-biologic systems is, IMO, a major flaw. Recently we've seen many crashes due to this design:
- AF447: biological system identified stall correctly, applied incorrect procedure, the other biological system was not able to monitor flying system's stick commands and was unable to correct. A perfectly flying airplane crashed as a result
- Germanwings: one biological system was temporarily unavailable due to maintenance, the other biological system malfunctioned, prevented access to the controls, and crashed the airplane
- Atlas air: biological system incorrectly identified acceleration due to (uncommanded?) TOGA as stall, and over applied stall recovery procedure; the other biological system correctly asses the situation and applied the right proceudre, which resulted in a yoke duel between the two piloting systems, however, the surface control system was not designed for such duels and broke off (a feature designed to prevent another type of problem), leading to each piloting system controlling only half of the elevator
Now read both of the above scenarios and think of the self-flying planes. Would you fly (as a passenger) on a plane which was designed in the same way, for two AI pilots? If not, why do you insist it's a good design for biological pilots? Try to view the situation without your inherent bias. Ask people who know nothing about airplanes (and don't depend on your salary) what they think of it...