Originally Posted by CONF Iture
Originally Posted by Takata
a PRIM reset is also mandatory before doing it
No, it is not.
You are right and I stand corrected on that point. I based that on the fact that many crew reseted their PRIM after ADR disagree events, but the procedure is mentioning clearly that Alternate can't be cleared until after landing.
On the other hand, RTL (Rudder Travel Limiter) rule out the reversion to alternate in AF 447 case. The fact that the rudder settings were still frozen after impact imply no reversion from ALT2 because it would also have cleared the RTL fault (having now two "good" ADRs back, even if both "wrong").
Consequently, IMO, it means that ADR DISAGREE situation was also not cleared until impact: they would never have had the opportunity to re-connect either autopilot or autothrust after 0210, while no other flight envelope protection other than "g load" would have been active before crash time. In this context, the possibility for a supposed induced "aircraft system upset" happening after 0210 is more than very thin. Don't you think?