I may be missing something, but I don't see them getting a problem cleaning up and going up to sort out the situation in a failsafe config - well, problem without MCAS at play.
I've it explained it previously on this thread but here it goes again.
When the stick shaker goes on at liftoff, the crew does not know why it did so. It could be for a number of reasons:
1) AoA signal could be faulty. This will cause other apparent failures such "Airspeed Unreliable" and "Altitude Unreliable". This is what happened for JT043, JT610 and ET302.
2) Airspeed could be totally inaccurate due to dual problems on both the left and right systems. It has happened before. The airplane could be dangerously slow. The AoA vane could be telling you the truth and you're teetering on the brink of a low speed, low altitude stall. Retracting Flaps could instantly stall the airplane with little chance of recovery.
3) One of the slat panels could be badly skewed or missing. Look at 7BOEING7's logo picture to see what a skewed slat looks like. Every 737 since the NG has a system that detects skewed or missing slats. If a skewed or missing slat is detected, the stick shaker defaults to the Flaps up schedule. As in Case 2, the crew doesn't know the airplane's actual condition. Retracting the Flaps could instantly stall the airplane due to a missing or skewed slat panel.
For Case 1, you can get away with retracting the Flaps.
For Case 2 & 3, retracting the Flaps could stall the airplane at low altitude with no chance of recovery.
The best course of action is to set pitch and power and climb to a safe altitude while monitoring airplane performance. Once at a safe altitude, sort out the airplane by running the "Unreliable Airspeed" procedure. There is little point in retracting Flaps now as you need to prepare to return to land at the origin airport. When the stick shaker went off, the mission should be aborted. Boeing procedures do not call for turning the stick shaker off by throwing the overhead panel circuit breaker. Do you think it's a good idea to complete the mission with the stick shaker going?
I know JT043 completed their planned flight with continuous stick shaker. Although that crew showed good airmanship skills for correct actions after the erroneous MCAS activation, those skills departed when they elected to complete their flight.
For Cases 1, 2 & 3, the airplane is alerting the crew that something is wrong. The crew needs to take actions to safeguard the airplane. These do not include retracting the Flaps and trying to complete the mission.
Last edited by OldAeroGuy
on Tue Apr 30, 2019 12:08 am, edited 1 time in total.