OT 737 Max Really interesting

[harry]

Well shit-fer-brains,a lot of people here have found it interesting. As I expected.

[dennis]

Nobody found the content interesting, there is nothing new.

They did say it was interesting that you hadn't posted some racist cr@p for a change.

So time to flush your head and get rid of the sh!t in it.

[Peter Parry]

No, the aerodynamic force on the elevator and stabiliser effectively locks the jackscrew and manual wheels. This is a separate problem with the 737 which has been known about since the early 1980's. The remedy for runaway trim is the "roller coaster" manoeuvre where the aircraft controls are relaxed to allow the aircraft to go where it wants so removing the aerodynamic force on the elevator and stabiliser and allowing the trim wheel to be turned a bit. The manual trim wheel is then held by one pilot while the other pulls back on the control column to regain a bit of height before repeating the process several times to allow the trim to get back to a more normal position (assuming you don't hit the ground first).

The electrical trim switches are disabled when MCAS is turned off and unfortunately if turned back on to try to use electrical power to trim the aircraft also turn MCAS back on. This has greater mechanical authority than the control column.

[Richard]

How can you say that nobody found the content interesting? Seems like he did flush his head and the result is posting as dennis@home.

[Andy Burns]

The ops manual says if you have to use the stabiliser trim cutout switches during a flight, you should never turn them back on during that flight, apparently the Ethiopian Airlines pilots made that mistake.

This chap has flown 727, 737 (but not max), 757 and 777, he has several videos on the 737-max which are worth a watch ...

[Peter Parry]

It would appear they had little choice if the manual trim was (as far as they were concerned) jammed. It takes several dozen turns of the trim wheel to go from full extension to neutral flight and as the airspeed increased the force on the jackscrew would increase. Failing to fully fix the trim before MCAS is deactivated can make it physically impossible for pilots to control the plane. Remember even the existence of MCAS didn't appear in any manuals.

The switch operation was also altered, with the 737NG autopilot cutout switch, you could have turned off autopilot and retained electric trim via yoke switches. However, on the 737 MAX, they changed the cutout switches into primary and backup, and the instruction is to switch both, which means for MCAS runaway, you lose electric trim altogether whereas on the earlier aircraft you could keep trim power operation and only lose the autopilot.

[tony sayer]

I hear that a single addendum page has been added to the 737 operating manual that says;

"If its going nose down then if all else fails fly the f****ng thing upside down till it corrects itself then twiddle it the right way up";)..

Rinse and repeat as necessary...