757 ELEVATOR PROBLEM

[ghiom 2]

HiDuring flight, the elevator is not flat. It is in position to make the aircraft go down, as if it had too much lift by itself.Can someone explain and/or tell me what to do to fix this, if possible?Thnk youGhiom

[FOD 23]

Ghiom,Not sure what you mean by flat? Don't forget that both the tailplane and the elevator move.In manual flying, you control pitch with the elevator then trim out the force with the tailplane.In autopilot, the elevator remains aligned to the tailplane and the aircraft is flown via the trim system {watch the elevator position indicator whilst manoeuvering in AP}.If you specify the configuration and how you are controlling the aircraft when you see this problem, I will have a look at it in the air.John R

[ghiom 2]

Here are some pictures. I hope it shows:Have you found something in the air file?Thank youGhiom

[FOD 23]

Ghiom,In your shots, the elevator appears centralised ie at zero angle to the tailplane. The tailplane appears to have a positive AoA and so will be generating lift. If the aircraft is flying straight and level hands off, this means in simple terms that the lift arm generated by the tailplane is just balancing the lift arm generated by the wings and the aircraft is properly trimmed out.If you change speed and re-trim, you will see how the tailplane moves to maintain the correct balance.As far as I can see, the PSS 757 tailplane/elevator system operates in the correct sense with positions that would be appropriate to the real aircraft.Hope this helps.John

[ghiom 2]

ThankEverything is fine then.I will put more weight in the aft section.Thank you againGhiom

[FOD 23]

Might be worth trying with more forward cargo and comparing the result ......John