ADIRS

Question 1

ADIRS Rotary Switch:

Answer 1

Three positions:
-NAV Normal Ops
-ATT provides Attitude and Heading only. Heading must be updated every 10 min. in MCDU.
-OFF

Question 2

Two types of IR Faults:

Answer 2

• Flashing: Attitude and Heading can be recovered in ATT mode
• Solid: IR has failed

Question 3

ADIRS Quick Alignment:

Answer 3

• 30 seconds
• Clears groundspeed only

Question 4

ADIRS; Complete Alignment:

Answer 4

• Clears groundspeed and Drift
• Captures present position
• 7-10 minutes

Question 5

The ADIRS are left ON the ground for:

Answer 5

• They provide information to calculate fuel density during fueling.

Question 6

IRS only navigation only in RNP airspace limitations:

Answer 6

• 6.2 hrs from IRS ground alignment
• 5.7 hrs from last FM position update

Question 7

When the ADIRS are on Battery power only:

Answer 7

• Horn will sound in the nose wheel well

Question 8

The Mix IRS position:

Answer 8

• FMGEC computes an average of the 3 IRS positions.
• If there is a dramatic difference in one position it will be factored in less than than the other two.

Question 9

Each FMGEC compares the mix IRS and mixed gps (GPIRS) . The difference is:

Answer 9

• The Bias
• Bias is constantly memorized by the system.
• If Radio or GPIRS is lost, the system will adjust the Mix IRS position using the bias for navigation.

Question 10

How many ADIRU’s

Answer 10

• 3

Question 11

Two parts of the ADIRU’S:

Answer 11

• ADR (Air Data reference): Baro, Airspeed, Mach, AoA, temp, and overspeed.
• IR (Inertial Reference): attitude, heading, flight path vector, accelerations, angular rates, ground speed, vertical speed, and aircraft position.