ADIRS Panel

Question 1

What is the ADIRS?

Answer 1

Air Data and Inertial Reference System

Question 2

What are some of the parameters that the Air Data Reference System provides?

Answer 2

B - Barometric altitude
O - Overspeed warnings
A - Angle of attack
T - Temperature
S - Speed/Mach

Question 3

What are some of the parameters the IR provides?

Answer 3

F - Flight Path Vector (FPV)
A - Attitude
T - Track
H - Heading
A - Acceleration
A - Angular rates
A - Aircraft position
G - Groundspeed

Question 4

If there was an IR1/ADR1 FAULT, what should be done with the switching panel to display backup data appropriately?

Answer 4

ATT/HDG to Capt 3

Question 5

If the AIR DATA portion of the #1 ADIRU failed, what should be done with the switching panel to display backup data appropriately?

Answer 5

Air Data to Capt 3

Question 6

Explain the ADIRS Power-up and Initialization.

Answer 6

• Switch from OFF to NAV
• ON BAT light illuminates and then extinguishes
• White ALIGN light illuminates for the duration of alignment (only on A319/
A321)
• In A320s, the E/WD memo section displays “IRS IN ALIGN” during
alignment and replaces the ALIGN lights on the overhead panel.

Question 7

What is the importance of observing the ON BAT light?

Answer 7

It confirms the ADIRS ability to revert to aircraft battery power.

Question 8

What are some indications of an ADIR having reverted to battery power on the ground?

Answer 8

• An external horn sounds
• An ADIRU & AVNCS light illuminates in blue on the external power panel.

Question 9

What is the significance of a steady FAULT light on the IR?

Answer 9

IR has failed and cannot be recovered

Question 10

What is the significance of a flashing FAULT light on the IR?

Answer 10

Navigation function is lost. Attitude and Heading may be recovered in ATT mode.

Question 11

Describe what would happen if an ADR was selected OFF?

Answer 11

• The pilots would lose barometric altitude, airspeed, Mach, angle of attack, temperature and over speed warnings from that one ADR.
• The ECAM would instruct the pilot to select the AIR DATA SWITCH to CAPT 3 or F/O 3 as appropriate.
• At that point the affected pilot’s side would return to normal.

Question 12

What functions are lost when an IR is turned OFF?

Answer 12

• There are two ADIRS control panels installed on the fleet. On the older panel with a keypad and digital display, the pilot would lose the IR part (Inertial Reference) which supplies attitude, flight path vector, track, heading, accelerations, angular rates, ground speed, and aircraft position, along with all the ADR information. The ECAM instructs the pilot to select the ATT HDG SWTG to CAPT 3 or F/O 3 as appropriate. At that point the affected pilot’s side returns to normal.
• The newer panel with no keypad and digital display allows the pilot to turn off only the IR, and in this case, only the IR information would be lost and the ADR information would still be available.