AirAsia flight missing

[Evan]

(Evan's acronym-laden list where in this situation you do this and in that situation such and such is disabled, but only when condition x exists- just doesn't seem the right way to design a plane where "fail-safe" and "intuitive" might be a good idea, nor a plane designed to operate counter to traditional aerodynamic responses.)

Yeah, let's see... The only equipment problem was that they were getting repeated AUTO FLT RUD TRV LIM SYS messages on ECAM. Hmmm... Let's call that "condition x"...

QRH and ECAM Procedure for "condition x": AUTO FLT RUD TRV LIM SYS (That's "acronym" for a rudder-travel limiter failure on both units) is as follows:

FAC1.........OFF then ON
FAC2.........OFF then ON

Oh my god! You're right!! How is anyone supposed to deal with that "acronym-laden list"?!! Certainly we can't expect a pilot to both fly a plane and cycle two overhead switches! No 3WE, once again, you've got right to the heart of the matter.

[3WE]

Yeah, let's see... The only equipment problem was that they were getting repeated AUTO FLT RUD TRV LIM SYS messages on ECAM. Hmmm... Let's call that "condition x"...

QRH and ECAM Procedure for "condition x": AUTO FLT RUD TRV LIM SYS (That's "acronym" for a rudder-travel limiter failure on both units) is as follows:

FAC1.........OFF then ON
FAC2.........OFF then ON

Oh my god! You're right!! How is anyone supposed to deal with that "acronym-laden list"?!! Certainly we can't expect a pilot to both fly a plane and cycle two overhead switches! No 3WE, once again, you've got right to the heart of the matter.

Maybe so. But hard overs happen for reasons beyond circuit breakers and there's many, readily available solutions other than a broad-fundamental-how-to-stall procedure and your failure to mention my partial list of other failure modes and interwoven systems is sidestepping the argument. Dog poop on your shoes again.

[Evan]

Maybe so. But hard overs happen for reasons beyond circuit breakers and there's many, readily available solutions other than a broad-fundamental-how-to-stall procedure and your failure to mention my partial list of other failure modes and interwoven systems is sidestepping the argument. Dog poop on your shoes again.

You are correct. Hardovers, like everything else, happen for a reason. The reason for this hardover was that the yanking of the FAC 1 circuit breakers—as opposed to the controlled process of taking an FAC off line with the aforementioned "acronym-laden list" of pushing an overhead switch—causes the system to react to the sudden voltage anomaly by commanding a momentary rudder deflection. Bad news? No, because a moment later the remaining system corrects the rudder movement, long before it can induce roll.

Oh... unless you then also yank the FAC 2 breakers, in which case you've killed everything that is controlling that rudder and it is left right where it is. But seriously, who would do that?

So... a rudder deflected at 2° will induce a high roll-rate and a crew focused on the top and rear of the cockpit apparently won't notice this for about nine seconds, at which point you are beyond the 45° threshold of the normal envelope and just arriving at the 53° point of unusual attitude.

That is, you are now in a bitching hard over. You are now in an unusual attitude wrapped within an unusual failure situation stuffed into an electrical bus mystery.

There is a way to avoid this turducken. It is to not stuff it up with IMPROVISATION.