AFCS

Question 1

How can IAS be controlled when the IAS upper mode is engaged?

Answer 1

By use of the beep trim

Question 2

Explain what you lose when you get the A. TRIM warning

Answer 2

1. Loss of follow up trim
2. Attitude hold

Question 3

Explain the difference between horizontal and vertical modes

Answer 3

Horizontal modes are HDG/NAV modes
Vertical modes are IAS, VS,

Question 4

Explain the pilot experience with the basic aircraft (no SAS), Backup SAS (3x SAS etc), AP SAS

Answer 4

Loss of A. TRIM
- No attitude hold/follow up trim
- Attitudes more challenging to hold and hover more difficult

Question 5

When identifying AFCS failures, where should the pilot look and what information can they gain?

Answer 5

CAD/Warn panel - Cautions/Warnings
APMS panel - System On/Off status
Upper PFD - Indicated the loss of an actuator in associated axis

Question 6

Explain the “force trim” system within the aircraft and how this relates to the FTR

Answer 6

Force trim is the artificial feel on the cyclic provided by springs, pressing the force trim release button releases these springs making the stick floppy

Question 7

Explain aircraft feel and available trim/AFCS systems after the SAS/AP Cut button has been pressed?

Answer 7

• The helicopter will feel unstable with all secondary effects clear
• The force trim system will still work and so will the FTR button but that’s it (No attitude hold, beep trim etc)

Question 8

Explain aircraft feel and available trim/AFCS systems when operating with backup SAS only

Answer 8

Note: Backup SAS means all P/R/Y SAS are engaged

Feel: As each SAS is engaged the aircraft feels more stable with less secondary effects present
System: FTR + beep trim working?

Question 9

Explain aircraft feel and available trim/AFCS systems when operating with AP SAS only

Answer 9

Note: AP SAS is when AP is engaged without A. TRIM by pressing the AP button then disengaging the A.TRIM

Feel: Identical to that of Backup SAS
Systems: AP is possible however with reduced accuracy

Question 10

Explain aircraft feel and available trim/AFCS systems when operating with A.TRIM functional

Answer 10

Feel: Aircraft is very stable with minimal if any secondary effects
Systems: Attitude hold, beep trim, FTR and push against/trim reset all functional

Question 11

Explain autopilot upper modes

Answer 11

Upper modes allow hands off flying through IAS, VS and HDG modes as well as GS (glide slope) and Nav modes

Question 12

Explain the difference between coupled AP and non coupled

Answer 12

Coupled AP allows the aircraft to fly with the AP system linked to a flight plan/approach procedure using NAV or GS/APP modes respectively

Question 13

Explain the difference between coupled and non coupled AP

Answer 13

Coupled AP allows the aircraft to fly hands off along an approach procedure or loaded flight plan using GS and NAV modes respectively

Question 14

Which upper modes are incompatible

Answer 14

Can’t have 2 horizontal or vertical at once
Horizontal: GS, VSI, IAS, ALT and ALT.A
Vertical: APP, HDG, NAV