FCTM ADIRS/IRS FAULT

Question 1

Each ADIRS has two parts (ADR and IRS), that may fail:

Answer 1

Independently of each other.

Additionally the IRS part may fail totally or may be available in ATT mode.

Question 2

Single NAV ADR FAULT or NAV IRS FAULT are simple procedures, and only require action on the:

Answer 2

switching panel as indicated by the ECAM.

Question 3

Dual NAV ADR or NAV IRS failures will cause the loss of:

Answer 3

AP, A/THR and flight controls revert to ALTN law.

Question 4

Due to the low probability of a triple ADR failure, the associated procedure will not be displayed on the ECAM. In this case, the crew will refer to:

Answer 4

QRH procedure for ADR 1 + 2 + 3 failure.

There is no procedure for IRS 1 + 2 + 3 failure but the ECAM status page will give approach procedure and inoperative systems. In this unlikely event, the standby instruments are the only attitude, altitude, speed and heading references.

Question 5

In the case of a triple ADR failure, AP and A/THR are lost and the flight controls revert to ALTN law. The NAV ADR 1+2+3 FAULT warning is triggered and the:

Answer 5

ECAM procedure requires that the 3 ADRs be switched OFF, to replace the PFD’s normal speed scale and altitude indication by the Back-Up Speed Scale (BUSS) and GPS altitude information.

There is no procedure for IRS 1 + 2 + 3 failure but the ECAM status page will give approach procedure and inoperative systems. In this unlikely event, the standby instruments are the only attitude, altitude, speed and heading references

Question 6

To switch off an ADR, the flight crew must use the:

Answer 6

ADR pb. Do not use the rotary selector, because this would also cut off the electrical supply to the IR part.