Autoflight

Question 1

The FMS can calculate the a/c position by 3 different methods, what are they, and which does the a/c use generally?

Answer 1

1. MIX IRS - avg posn using the three IRS
2. Radio - exact post using precise radio fix, VOR/VOR, VOR/DME, etc.
3. GPS - exact post based on 2 independent GPS satellites.
   Generally uses mix GPIRS

Question 2

What is meant by the term BIAS with regards a/c posn?

Answer 2

The vector from the MIX IRS posn to the radio/GPIRS posn calculated by each FMGC. If radio/GPIRS posn lost, FMGC can calc posn using MIX IRS + BIAS.

Question 3

When will the energy circle display on the ND and what does it represent?

Answer 3

Represents required distance to land. Only if in HDG/TRK, FMS in cruise, descent or appr mode and within 180nm of dest.

Question 4

How does FMS detect engine out condition?

Answer 4

Eng master switched off
Eng N2 below idle
One Eng N1 is above 85%
FADEC detects eng fault

Question 5

If EO CLR is pressed in the progress page by mistake what are the implications?

Answer 5

Restores the all engine operative predictions and performance. Reverting to one engine-out performance again is not possible.

Question 6

What is the ‘ENG OUT REC MAX’ calculation based on and is this level fixed?

Answer 6

LRC OEI max. FL with a/ice off based on a/c weight

Question 7

How many channels does the a/thr have?

Answer 7

Two. One per FMGC.

Question 8

When will THRUST LOCK occur and what are the recovery actions?

Answer 8

Activates if non-standard A/THR disconnection occurs. Engines maintain thrust at value set before d/c, FMA flashes THR LK, ECAM ENG THRUST LOCKED every 5s.

Move thrust levers to deactivate.

Question 9

What is RETARD MODE and when does it activate?

Answer 9

Only available during an auto land.
1. At least one AP engaged. LAND and A/THR SPEED
2. FLARE mode
3. Approx 30ft RA, A/THR RETARD engages, sets THR IDLE
4. RETARD call to move THR LEVER
5. When THR LEVER at IDLE detent, RETARD disengages

Question 10

How does SPD mode function on final approach?

Answer 10

groundspeed mini

Question 11

How many FACs are there, and what function do they perform?

Answer 11

2 FACS:

1. Yaw Function: yaw damping & turn coordination, rudder trim, rudder travel limitation
2. Flight Envelope Function: PFD scale management, alpha-floor protection
3. Low Energy Aural Alert Function
4. Windshear Detection Function