Trimable Horizontal Stabilizer

Question 1

How is the Trimmable Horizontal Stabilizer (THS) normally operated in flight?

Answer 1

The flight control computers control trim functions automatically

Question 2

If no hydraulic power is available, what is the impact on the THS?

Answer 2

The THS requires hydraulic power from the GREEN or YELLOW systems in order to function

Question 3

If possible, how can the THS be postition after a complete flight control computer failure occurs?

Answer 3

Mechanical trimming is possible by manually position the pitch trim wheel.

Question 4

Explain what would happen if a pilot were to reach down and move the pitch trim wheel when all systems are working normally?

Answer 4

The trim can be trim manually. However, manual inputs have priority over computer inputs, so the autopilot would disconnect (if engaged)

Question 5

What happens to the THS after landing

Answer 5

The trim automatically resets to zero.