Originally Posted by
Bergerie1
Simple questions. How many of you would retract the flaps when a stall warning is sounding off? Why would you do something which will raise the stall speed? Surely, the best thing to do would be to maintain the configuration and fly pitch and power while you try to sort out the multiple warnings.
A very reasonable question depending on your frame of reference. I have previously suggested that one of the things that we may be seeing play out in these events is a flight crew response that reflects the way in which they were trained and managed. In particular, if the pilots' training and operational environment placed a high degree of emphasis on following procedures as written rather than stepping back and looking at the "big picture" to determine if the procedure was appropriate at that time, then I would think that flap retraction would be a normal and expected step. Why? Because the crew is essentially running two procedures at the same time - the "After Takeoff" checklist and the "Airspeed Unreliable" checklist (and if they haven't identified the unreliable airspeed, they are still doing the After Takeoff checklist anyway). Since the "Airspeed Unreliable" checklist does not literally say to leave the flaps where they are until the reliable instruments have been determined, it may have been completely natural for the crew to continue to run the "After Takeoff" checklist which would mandate retracting the flaps.
I found it very interesting just after MCAS activated during the second Lion Air flight, the crew actually extended the flaps after having retracted them. The MCAS input stopped, although the stick shaker was still going. After a short time they retracted them again setting the stage for MCAS again. I would really love to know what they were thinking. Perhaps we will find out when the full CVR transcript is published with the final report.
I've mentioned before that the FCOM states quite clearly that the manufacturer cannot write a procedure for every possible set of circumstances, but some airlines give this concept very little consideration. If one's training and background includes a "big picture" emphasis, then I suspect then that there would be some hesitation to retract flaps with an active stall warning. If one's training emphasized following the written procedure without modification, then the flaps are probably going to come up - as we saw in all three of the incident/accident flights.