Originally Posted by
Lyman
Dozy regarding my fishing.... It is Airbus who warns not to reselect Autopilot: "The autopilot may command undesirable Pitch attitudes, resulting in damage to the aircraft" (or something like that.) It is not I who first asked re: the autopilot in AL. If as you say reselect is impossible, why do Airbus warn pilots not to "reselect"? For that matter, why do they direct the pilot to turn off a/p as part of the drill? Isn't it already off, and "latched out"? Hmmm?
Sometimes those in conflict are both right...
I think / recall that the a/p-off latch depends on precisely which law the a/c gets into. That depends on how many ADRs fail and for how long and maybe in which order. That in turn depends on which pitots ice up, how badly, and maybe in which order - which will vary.
I recall that there has been at least one case where a/p
was re-engaged soon after UAS and did the wrong thing due to speeds being in agreement but still erroneous.
The line in the procedure looks like it is to
ensure that ap/fd are off (they might have dropped out but maybe not). I think there has been additional guidance (that's come up on these threads) about not re-engaging them too quickly (ensure speed info is back to normal first).