Failure of the CFDIU Detected by the RA 1

TASK 31-32-00-810-853-A
Failure of the CFDIU Detected by the RA 1

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 313202
AMM 31-32-34-000-001	Removal of the CFDIU
AMM 31-32-34-400-001	Installation of the CFDIU
AMM 34-42-00-740-002	BITE Test of the Radio Altimeter

3. Fault Confirmation
Subtask 31-32-00-865-101-A

A. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	COM NAV/RAD ALTM/1	1SA1	K11

Subtask 31-32-00-740-154-A

B. Test
Do the BITE test of the radio altimeter (system 1) AMM 34-42-00-740-002.

4. Fault Isolation
Subtask 31-32-00-810-102-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message RADIO ALTMI NO DATA FROM CFDIU:

(1) If the fault continues:

Do a check and repair the wiring from the CFDIU (1TW) pins AA/2B, 2C to the first terminal block, ASM 313202.

Subtask 31-32-00-810-102-C ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message LRRA-1: NO DATA FROM CFDIU:

(1) If the fault continues:

Do a check and repair the wiring from the CFDIU (1TW) pins AA/2B, 2C to the first terminal block, ASM 313202.

Subtask 31-32-00-740-155-A

B. Do the test given in Para. 3.B.

[Rev.8 from Aug 2018] 2026.04.04 04:29:51 UTC