Trimmable Horizontal Stabilizer

Question 1

How the THS is normally operated in flight?

Answer 1

The flight control computers control trim functions automatically

Question 2

If NO hydraulic power is available can the THS be positioned?

Answer 2

No. The THS requires hydraulic power from the Green or Yellow systems.

Question 3

If a complete flight control computer failure occurs can the THS be positioned?

Answer 3

Yes, mechanical trimming is possible by manually positioning the Pitch Trim Wheel.

Question 4

Can you move the PITCH trim wheel if all systems are working normally?

Answer 4

Manual inputs have priority over computer inputs. The autopilot will disconnect.

Question 5

What happens to the THS after landing?

Answer 5

The trim automatically resets to zero after entering Ground mode.
note: Following nosewheel touchdown, as the pitch attitude becomes less than 2.5 degrees for more than 5 seconds, the aircraft enters Ground Mode.