Thread: Ethiopian air lines flight goes down all killed

Why didn't he press the autothrottle disengage switch twice. Bloody thing flashing away and nobody doing anything about it

Thanks for posting that, Old Farang. It's sort of how it works in the NG, except you have the added distraction of the speed trim running throughout the initial climb. Perhaps the classic doesn't have that. I haven't flown the classic though.

The way we run memory checklists is a little more regimented than those 2 lads. Nevertheless, they got the stab trim cutout switches, which is most important. The other thing the NG has is a folded handle inside the trim wheels. Now I know why. They had a hard time winding the wheel without it, and when you're talking 50 or more rotations of the wheel to counteract configuration, thrust and speed changes - it's a lot of work.

0314_boeing_737_max8_trim_1x1.jpg

They are the two guarded switches above the #2 fire switch.

The other thing the NG has is a folded handle inside the trim wheels.

Yes, from what I have read it is still there on the Max. It is apparently well known for whacking you in the knee if left deployed! Maybe why they did not use it?

Is it right the disengage button can be pushed, but then the sensor problem causes it to reengage?

Originally Posted by DiscoMick

Is it right the disengage button can be pushed, but then the sensor problem causes it to reengage?

There is no disengage button per-se. Just the control wheel switches and the stab trim cutout switches.

If the autopilot is engaged, the MCAS should not activate (A stabilizer runaway can happen at any time). If the autopilot is disengaged and the MCAS senses an impending stall, it will inhibit the autopilot (cannot be engaged).

If the MCAS activates, operating the stab trim switches on the control wheel will momentarily stop the trim running. However, if the condition still exists, the trim may start running again. That is the same as the speed trim after takeoff (runs on its own). So yes, the trim will start running again after a short period.

The above applies whether the MCAS is functioning or malfunctioning.

The only was to stop the stab trim from running in all situations is to operate the stab trim cutout switches (pictured above, and shown in Old Farang's video).

Yes, I've been whacked by that bloody handle in the sim when practising the stab trim runaway procedure. It smarts. I don't know whether the classic has it or not. The lads in the video didn't coordinate the whole scenario very well. Perhaps they forgot to extend the handle?

Thanks. I don't understand this stuff, so good to hear your explanation.

This is the trim wheel (captains side). The handle is extended in the second pic.

Not sure how much of this may be "fake news", but interesting read anyway:

Ethiopian Airlines Had a Max 8 Simulator, but Pilot on Doomed Flight Didn’t Receive Training On It - The New York Times

40 seconds to avoid disaster. Not knowing any thing about the system, I have to take it as read.

Latest testing of Boeing jet finds pilots have 40 seconds to avoid ‘disaster’