Posts by user "island_airphoto" [Posts: 10 Total up-votes: 14 Pages: 1]

Originally Posted by donpizmeov

Didn't the 73max stay operational after the Lion air accident?

Originally Posted by Lonewolf_50

I got the idea that with no (or very little) thrust, and with the aircraft falling, the pilot (may have) realized that he was in out of control flight , and falling.
In a pedantic sense: if you make control inputs, and the aircraft won't or can't respond to them, you are in out of control flight .
The whole event happened pretty quickly. How far into "we are doomed" that his senses told him they were can have informed his decision to say something about it. (the human mind is an interesting thing).
There's also the matter of temporal distortion which can happen during stress or high adrenalin events. (I experienced that during the course of an aircraft accident: not on topic for this thread).
As to conformance with ICAO, not all investigations make good on that.



I sincerely hope that this one does.

(Note: some of what I refer to as out of control flight seems to be called upset in commercial transport jargon).

Originally Posted by Pilot DAR

I distinguish between "upset" and "out of control" for any airplane. "Upset" to me implies an unusual attitude, headed for worse if a correction is not made quickly. An airplane can be stalled, and out of control, but not upset. The pilot may no longer have any control effectiveness available to pitch up, so the airplane is not in control in that sense, though it otherwise is stable (for the moment). I saw in the video an airplane which, after suffering a [total] power loss in a climb pitch attitude, and a climb speed, did not noticeably pitch down, so it certainly would have been slowing down, and approaching a stall. If the pilot maintained the attempt to pitch up, and the airplane was not aerodynamically able to respond, it was not in control, so, out of control.

I encountered this thinking while flight testing a modified GA plane in the company of an experienced test pilot. The airplane would bob across an airspeed range with full nose up pitch control. It was a very stable bob, but the indicated airspeed would increase and decrease about 5 knots during this bobbing, while the controls were held against the nose up stop. I asked him, was the indicated stall speed the faster, or slow of the two airspeeds? His reply: "Can you control the airspeed while the airplane is slower than the faster speed?". "No" I replied. Then the airplane is out of control at the faster airspeed, and that is the stall speed. The fact that it would fly slower was not in my control, though the airplane was still controllable in roll and yaw.

It's a fine point, but this event is well into fine point territory!

Originally Posted by za9ra22

OK, from my standpoint as a curious observer, what would their options be? They don't have engines to provide thrust, they don't have altitude to lower the nose and gain speed, and they don't have the speed to pull the nose up and extend the glide? All while trying to troubleshoot the same problem we've collectively taken 2 weeks to not understand. What would you do?

Originally Posted by Lonewolf_50

Then why didn't that happen on the previous flight from Deli to Ahmedabad, or any of the previous flights since that install in March?

Thanks for the update, and in particular that bolded bit.

Originally Posted by Lonewolf_50

Thank you for that answer, edge cases do abound in complex systems, but would not moving the throttles forward by hand (as the thrust was beginning to reduce {for that strange reason}) overcome that and restore thrust?
(As I don't fly the 787, I may be missing something basic on how the systems work).

Originally Posted by NSEU

The FCOM explains that the system only operates when there is a large thrust to weight ratio and will maintain the required climb performance. If applied during an engine out, it will provide directional control only when airspeed drops below normal operating speeds.