8. ADIRS Panel (Navigation) Flashcards
What is the ADIRS?
Air Data and Inertial Reference System
What type of information does the Air Data Reference System provide?
Barometric altitude, airspeed, over speed warnings, temperature, angle of attack, mach.
What type of information does the IR provide?
Attitude, Flight Path Vector (FPV), track, heading, acceleration, angular rates, groundspeed and aircraft position.
If there was an IR1 FAULT, what should be done with the switching panel to display backup data appropriately?
ATT/HDG to Capt 3
If there was an ADR1 FAULT, what should be done with the switching panel to display backup data appropriately?
AIR DATA to Capt 3
Explain the ADIRS Power-up and Initialization.
• Switch from OFF to NAV
• ON BAT light illuminates and then extinguishes
• White ALIGN light illuminates for the duration of alignment (only on A319; 502-534)
• In A319; 535,536, A320s, and A321s, the E/WD memo section displays “IRS IN ALIGN” during alignment and replaces the ALIGN lights on the overhead panel
What are some indications of an ADIR having reverted to battery power on the ground?
• An external horn sounds
• The ON BAT light comes on
• An ADIRU & AVNCS light illuminates in amber on the external power panel
What is the significance of a steady FAULT light on the IR?
IR has failed and cannot be recovered
What is the significance of a flashing FAULT light on the IR?
Navigation function is lost. Attitude and Heading may be recovered in ATT mode.
Describe what would happen if an ADR was selected OFF?
• The pilot 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 SWTG to CAPT 3 or F/O 3 as appropriate.
• At that point the affected pilot’s side would return to normal
What functions are lost when an IR is turned OFF?
• 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
When would a pilot perform a complete alignment versus a fast alignment?
Complete Alignment:
• Before the first flight of the day
• When there is a crew change
• When the departure airport is located between latitudes 2 o north and 2o south
• 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 more than 3 hours
Fast Alignment:
• If a complete alignment is not necessary and the difference between the IRS position and the FMGC position is greater than 5nm.
What could cause the flashing white ALIGN light to illuminate on the ground?
• PPOS not entered within 10 minutes of alignment or within 3 minutes of fastalignment
• Large difference in LAT/LONG between shutdown position and entered position
• Aircraft movement during alignment
ADIRS Panel - 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 aircraft
