[ams6110]

Read the narrative in the report. Why do you suppose that after they got the same initial signs of trouble that the Lion Air flight had (stick shaker on left side, disagreement in airspeed values, etc. immediately after takeoff) that the captain tried to engage autopilot and instructed the first officer to retract flaps and inform controllers they were proceeding to climb to FL 320 (32,000 ft). Why not instead turn back and land and hand the aircraft over to maintenance?

From the report:

At 05:38:44, shortly after liftoff, the left and right recorded AOA values deviated. Left AOA decreased to 11.1° then increased to 35.7° while value of right AOA indicated 14.94°. Then after, the left AOA value reached 74.5° in ¾ seconds while the right AOA reached a maximum value of 15.3°. At this time, the left stick shaker activated and remained active until near the end of the recording. Also, the airspeed, altitude and flight director pitch bar values from the left side noted deviating from the corresponding right side values. The left side values were lower than the right side values until near the end of the recording.

...

At 05:39:06, the Captain advised the First-Officer to contact radar and First Officer reported SHALA 2A departure crossing 8400 ft and climbing FL 320.

...

At 05:39:42, Level Change mode was engaged. The selected altitude was 32000 ft. Shortly after the mode change, the selected airspeed was set to 238 kt.

At 05:39:45, Captain requested flaps up and First-Officer acknowledged. One second later, flap handle moved from 5 to 0 degrees and flaps retraction began.

Bear in mind stick shaker and divergent instrument readings all this time.

Why not just return and land, leave the flaps configuration alone (which would have inhibited MCAS), especially since this is exactly how the Lion Air flight started.

I know this is easy to critique from the comfort of my chair, and the pilots are not here to defend themselves, but some things in this narrative just don't make sense.

[phire]

With hindsight, we know that retracting the flaps was a bad idea.

But check Boeing's MCAS bulletin, which is the only official information pilots received about MCAS at the time of the flight.

http://www.b737.org.uk/images/aoa-bulletin.jpg

It makes zero mention of flaps. It doesn't recommend avoiding retracting them or trying to land as soon as possible.

Trying to land as fast as possible is typicality a bad idea. Planes which have just taken off are almost always over their maximum landing weight. Even if you ignore that, the extra stress of trying to land as soon as possible could cause the pilots to make more errors.

Procedures for issues on take off are typically focused on continuing to climb to gain as much altitude as possible to give the pilots time and space to assess the problem before dumping fuel and landing. The more altitude you have the more time you have to recover.

And unfortunately, climbing through 5000 feet requires retracting the flaps.

[cmurf]

Check the airspeed at the time they raised flaps. It was right at Vfe, and increasing.

I don't know the most likely consequence of flying with flaps 5 above Vfe. Maybe flaps would (asynchronously) depart the airplane, or induce flutter at a much lower than usual airspeed. Either of those is an extremely high risk of losing the aircraft.

[cmurf]

Stick shaker activation isn't a rare event. Quite a lot of stick shaker events happen in low risk situations. And quite a lot of them are false positives. http://www.atsb.gov.au/publications/2012/ar-2012-172.aspx

Experience sounds like a good thing on the face of it, but it also adds noise where all of these indications sound familiar enough, and yet nothing in particular stands out and tells you to leave flaps alone. That suggestion isn't even in the emergency airworthiness directive. And still at the time of this event there's no simulator that can be configured for MCAS upset so that pilots can experience it in various phases of flight.

Also, the priority in a flight control problem is to fly the plane, get it stabilized, understand the problem, and turning back to the airport is inconsistent with that. Fly runway heading is the proper thing to do, it's less complicated. A turn increases angle of attack, increases drag, it makes a high angle of attack situation worse, and if you're trying to climb it reduces your rate of climb.

[cjbprime]

Of course they would have tried to land after getting the plane under control. They didn't have airspeed or altitude under control, and were following the checklists they were supposed to be following. IAS Unstable tells them to leave thrust high and flaps alone to avoid a wing stall.