My Letter to the Editor of New York Times Magazine

Re:My Letter to the Editor of New York Times Magazine by mlyle on Monday October 14, 2019 @12:45PM (#21250188)

> I have not read anything to suggest that a normally trimmed, MCAS-disabled Max would pitch itself into a stall from thrust application. That would be bad, but is also almost surely far from the actual situation.

?? Most aircraft will do this. Even docile trainers.

https://www.youtube.com/watch?v=DZfOtvjJR-I [edit: watch this instead https://youtu.be/6RtVdmsx4qU?t=71 ]

There's been a couple 747 crashes due to this exact scenario. Or regarding the 737 in particular, to quote "Mike734" in 2007:

> In the B-737 too much nose up trim can make a go-around very exciting. The under wing engines create a very large pitch up when adding full power for a go-around. The pilot has to really push hard to stop the jet from pitching too far nose up.

and "Cac737":

> Now in the Boeings for example, B737 and bigger with underslung engines, this situation is aggravated even more because when you push the power levers forward for go-around thrust, due to where they are and their thrust lines, that act alone will cause the nose to rise very noticeably, and if you are light you can actually find yourself pushing forward on the control column on a go around. now trim "back" as you say and forgetting you did so, can find yourself in a very nosehigh attitude if not careful.

https://www.airlinepilotforums.com/hangar-talk/17446-trim-la...

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Re:My Letter to the Editor of New York Times Magazine by FabHK on Monday October 14, 2019 @01:33PM (#21250701)

> ?? Most aircraft will do this. Even docile trainers.

That might be, but the video doesn't demonstrate it - the pilot flying pulls the elevator back quite a bit to induce the stall after he puts in full power.

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Re:My Letter to the Editor of New York Times Magazine by mlyle on Monday October 14, 2019 @01:40PM (#21250782)

I agree it's a poor demonstration-- he helps it the last bit of the way to the stall. But look at how much it pitches first...

Unfortunately there's two videos I found of the trim stall demonstration on youtube-- this one which shows most of it with a full cockpit view, and one which I think is a bit better technically but has the camera shaking everywhere.

See FAA AFM 4-12 for official training materials. https://www.faa.gov/regulations_policies/handbooks_manuals/a...

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Re:My Letter to the Editor of New York Times Magazine by mlyle on Monday October 14, 2019 @01:49PM (#21250885)

Here is a better demonstration:

https://youtu.be/6RtVdmsx4qU?t=71

The plane goes way above the normal climb attitude. He doesn't take it to the full stall, but has to push heavily on the control column to arrest it-- he never pulls.

(Really, it's pretty astounding how hard you have to push, and how high the nose rises anyways-- even if you weren't fully trimmed for glide, and even in mild-handling airplanes... I tend to fully trim for whatever flight condition I'm in, --except glide-- and then am holding light backpressure just to control this).

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