Originally Posted by
737 Driver
Performing these actions is no more difficult than executing the procedures for an engine fire/failure at V1, and we should not expect any less from a trained and competent commercial flight crew.
Ordinarily I would agree, however, the problem here is that there was a fundamental SA failure in the process of all of these events.
In the flight prior to JT610, the crew did not initially comprehend what was happening, perception was initially missing. The crew did eventually recover from that state when there was intervention by the 3rd flight deck person drawing attention to the trim behaviour. SA-1 Perception Failure. Thereafter the crew went for a 2 hour transit with the stick shaker running in the background...
On JT610, the crew had an SA-1 Perception failure to start with as well, and arguably detected the uncommanded stab motion and thereafter had an SA-2 Comprehension failure, which occurred with the handover to the FO of the aircraft while the Capt commenced further investigation. The Captains handover resulted in the effective termination of intervention from corrective trim input by the FO. Arguably there was an SA-3 type failure at the same time, as the Capt did not project forward the implications of not continuing the intervention of the trim input by MCAS, which led directly to the aircraft being so far out of trim that the dark knowledge of the potential for the trim being defeated without a specific manoeuvre to unload the stab was not realised. The FCOM is underwhelming on the subject, and the Capt ran out of ideas, time, altitude and elevator authority promptly.
ET had some information provided per the EAD, however, the crew had SA-2 failure once again.
Training of runaway stab is not a common item, and training for severe out of trim cases is effectively non-existant, and the FCOM hardly suggests that the matter may end up being critical for recovery time/altitude. If the crews are to be expected to respond appropriately, then sufficient knowledge and training is necessary so that the crew can make a decision based on recognition (RPDM) or if time permits, by analysis. As the crew were still ill informed that control loss was quite possible, and that a recovery would need a procedure that was not meaningfully described and not trained, it is difficult to shoot the messenger, the crew in question.
The SA failures that occurred here occurred in a period of dynamic operations and with high levels of stress on the decision makers. The truth is that people will respond differently with the set of cues that were in play on these occasions, and training to improve the likelihood of a desirable outcome is necessary. Keeping pertinent information from the flight crew was unhelpful, and the FCTM discussion on out of trim events fails to indicate the criticality of the situation, one that raises questions on the basis of certification of the aircraft in the first place.
The crew did try to fly the plane, they didn't recognise the problem, they didn't comprehend what the situation was promptly, and when breaking the manual trim process they did not project the state forward as a result of that action, due to inadequate information and training. Were they flying the plane? they were, but they didn't know they had brought a knife to a gun fight.
The FCTM is a bland understatement of a potentially catastrophic situation.