ADIRS Panel (Rev. 5)

Question 1

What is ADIRS?

Answer 1

Air Data Inertial Reference System

Question 2

What type of information does ADIRS provide?

Answer 2

• Baro altitude
• Airspeed
• Overspeed warnings
• AoA
• Temp
• Mach

Question 3

What type of information does the IR provide?

Answer 3

• Groundspeed
• A/C position
• Attitude
• Angular rates
• Flight Path Vector (FPV)
• Heading
• Acceleration
• Track

Question 4

If there was an IR 1 FAULT, what should be done with the switching panel to display backup data appropriately?

Answer 4

ATT/HDG to Capt 3

Question 5

If there was an ADR 1 FAULT, 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 illuminates and then extinguishes
• White ALIGN light illuminates for the duration of alignment (A319 only)
• In 535, 536, A320 and A321 the E/WD memo section displays “IRS IN ALIGN” during alignment and replaces the ALIGN lights on the overhead panel

Question 7

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

Answer 7

• An external horn sounds
• The ON BAT light comes on
• An ADIRU & AVNCS light illuminates in amber on the external power panel

Question 8

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

Answer 8

IR has failed and cannot be recovered

Question 9

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

Answer 9

• Navigation function is lost

- Attitude and heading may be recovered in ATT mode

Question 10

Describe what would happen if an ADR was selected OFF?

Answer 10

• The pilot would lose barometric altitude, airspeed, Mach, AOA, temperature and over speed warnings from that one ADR
• The ECAM would instruct the pilot to select the AIR DATA SWTG to CAPT 3 or FO 3 as appropriate
• At that point the affected pilot’s side would return to normal

Question 11

What functions are lost when an IR is turned OFF?

Answer 11

• 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 (inertial reference) part which supplies attitude, flight path vector, track heading, accelerations, angular rates, ground speed, and A/C position, along with all the ADR information. The ECAM instructs the pilot to select the ATT HDG SWTG to CAPT 3 or FO 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

Question 12

When would a pilot perform a full alignment versus a quick alignment?

Answer 12

Full alignment:

- Dep airport between 2° north and south 
- First flight of the day
- Crew change
- If GPS is not available and NAVAID coverage is poor on the expected route
- If GPS is not available and the expected flight time is 3+ hours

Quick alignment:
- For all other flights, if the deviation of the IRS position from the FMGC is greater than 5nm

Question 13

What could cause the flashing white ALIGN light to illuminate on the ground?

Answer 13

• No PPOS not entered within 10 minutes of alignment or within 3 minutes of fast alignment
• Bad position. Large difference in LAT/LONG between shutdown position and entered position
• Movement (A/C) during alignment

DIFFERENCES:
- No align light on A320: the E/WD memo section displays “IRS IN ALIGN” during alignment and replaces ALIGN lights on the overhead panel. This memo flashes in green for the same reasons as the ALIGN lights flash on the other A/C