34-10 AIR DATA/INERTIAL REFERENCE SYSTEMS (ADIRS)
10-01 ADIRS
2. RECTIFICATION INTERVAL - C
3. NUMBER INSTALLED - 3
4. NUMBER REQUIRED FOR DISPATCH - 2
5. REMARKS OR EXCEPTIONS
a) IR
P E L (P=performance ADD, E= ETOPS L=Land mode downgrade)
One may be inoperative provided:
1) Both flight controls Nz accelerometers are operative, and
2) Both flight controls Rate Gyros are operative.
ETOPS
IR 1 and IR 3 must be serviceable for ETOPS operation. If dispatch is made with IR 1 or 3 inoperative, raise a PADD downgrading aircraft to Non ETOPS.
Note : If IR 1 is inoperative, the TCAS is inoperative.
[Apply 34-43-01 (TCAS)
If IR 1 inoperative, the Terrain function of the EGPWS is also inoperative.
Apply 34-48-02 (EGPWS)
Consider 34-10-03-A) (ATT HDG), and Consider 34-22-01/02-A) (STBY), and Consider 34-42-01 (RA)]
b) ADR
2. RECTIFICATION INTERVAL - C
3. NUMBER INSTALLED - 3
4. NUMBER REQUIRED FOR DISPATCH - 2
5. REMARKS OR EXCEPTIONS
One may be inoperative.
ETOPS ADR 1 and ADR 3 must be serviceable for ETOPS operation.
If dispatch is made with ADR 1 or 3 inoperative, raise a PADD
downgrading aircraft to Non ETOPS.
[Consider 27-93-01-C) (PRIM), and Consider 34-10-03-B) (ATT HDG), and Consider 34-21-01/02 (STBY), and Consider 34-42-01 (RA)]
Note : If ADR 1 is inoperative, the GPWS or EGPWS is also inoperative.
[Apply 34-48-01 (GPWS) or Apply 34-48-02 (EGPWS)
or yes 3 installed and you can go with 2!