Autoflight

Question 1

FMS can calculate position by 3 different methods. What are they?

Answer 1

MIX IRS:
• average position of the 3 IRS positions calculated by accelerometers

Radio:
• position based on precise radio fixes

GPS:
• exact position calculated by 2 GPS satellites

The a/c will use most accurate which is GPS

Question 2

What is meant by position BIAS?

Answer 2

It’s added to the mix IRS position using the GPS or radio position so that if GPS is lost, it has an accurate starting position

Question 3

When does the energy circle display on the ND? What is it?

Answer 3

Appears in HDG/TRK mode

Shows distance required to complete a landing from present position

Question 4

How does FMS detect engine out condition?

Answer 4

• Engine master switch OFF
• Engine N2 below idle
• one thrust lever below 5* and the other above 22*
• FADEC detects engine fault

Question 5

If EO CLR is pressed by mistake what happens?

Answer 5

System assumes 2 engine ops again and single engine performance figures cannot be recovered

Question 6

What is EO REC MAX calculation based on?

Answer 6

Aircraft weight

It’s the max altitude a/c can fly with MCT set and maintain level flight

Question 7

How many channels does auto thrust have?

Answer 7

2…one per FMGC

Question 8

When does THRUST LOCK appear and how do you recover?

Answer 8

Only occurs when thrust levers are set in CLB or MCT gate and auto thrust is on.

Move thrust lever donuts to where the actual thrust is

Question 9

What is RETARD mode?

Answer 9

Active during auto land when idle thrust is commanded and activates at 40ft. Calls out RETARD at 20ft on manual landing and 10ft on auto land

Question 10

How many FACs are there? What functions do they perform?

Answer 10

2 FACs
• yaw functions (damping, turn coordination, rudder travel limiter)
• low energy warning
• windshear detection
• PFD speed scale & speed calculations
• flight envelope calculations