Trimmable Horizontal Stabilizer

Question 1

TRIMMABLE HORIZONTAL STABILIZER

Q: How is the​ THS normally operated​ in flight? ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Answer 1

Ref: (FOM VOL. III-DSC-27-10-20)​ ​

The​ flight control computers​ control trim​ functions automatically

Question 2

TRIMMABLE HORIZONTAL STABILIZER

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

Answer 2

Ref: (FOM VOL. III-DSC-27-10-10)​ ​

No - the​ THS​ requires​ hydraulic power from the​ Green or​ Yellow systems

Question 3

TRIMMABLE HORIZONTAL STABILIZER

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

Answer 3

Ref: (FOM VOL. III-DSC-27-10-20)​ ​

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

Question 4

TRIMMABLE HORIZONTAL STABILIZER

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

Answer 4

Ref: (FOM VOL. III-DSC-27-10-20)​ ​

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

Question 5

TRIMMABLE HORIZONTAL STABILIZER

Q:​ What happens to the​ THS when the​ aircraft enters into Ground​ Mode?​ ​

Answer 5

Ref: (FOM VOL. III-DSC-27-20-10-20)​ ​ ​

The​ trim automatically​ resets to zero​ (inside​ the​ green​ band)