Trimmable Horizontal Stabilizer Flashcards
How is the Trimmable Horizontal Stabilizer (THS) normally operated in flight?
The flight control computers control trim functions automatically.
If no hydraulic power is available, what is the impact on the THS?
The THS requires hydraulic power from the GREEN or YELLOW systems in order to function.
If possible, how can the THS be positioned after a complete flight control computer failure occurs?
Mechanical trimming is possible by manually positioning the pitch trim wheel.
Explain what would happen if a pilot were to reach down and move the pitch trim wheel when all systems are working normally.
The trim will can be turned manually. However, manual inputs have priority over computer inputs, so the autopilot would disconnect (if engaged).
What happens to the THS after landing?
The trim automatically resets to zero.
