Failure of the RA Antennas 1

TASK 34-42-00-810-820-A
Failure of the RA Antennas 1

1. Possible Causes

XCVR-RA, 1 [2SA1]
wiring between the RA reception antenna 1 (5SA1) and the RA transceiver 1 (2SA1)
wiring between the RA transmission antenna 1 (6SA1) and the RA transceiver 1 (2SA1)
ANTENNA-RA RCPTN, 1 [5SA1]
ANTENNA-RA XMSN, 1 [6SA1]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 34-42-00-740-002	BITE Test of the Radio Altimeter
ASM 344201
AMM 34-42-11-000-001	Removal of the Radio Altimeter Antenna
AMM 34-42-11-400-001	Installation of the Radio Altimeter Antenna
AMM 34-42-33-000-001	Removal of the Radio Altimeter Transceiver
AMM 34-42-33-400-001	Installation of the Radio Altimeter Transceiver

3. Fault Confirmation
Subtask 34-42-00-740-076-A ** ON A/C NOT FOR ALL

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

4. Fault Isolation
Subtask 34-42-00-810-071-A ** ON A/C NOT FOR ALL

A. If the BITE test gives the maintenance message CHECK LRRA-1 ANTENNAE CIRCUITS:

(1) If the fault continues:

do a check of the wiring between the RA reception antenna 1 (5SA1) and the RA transceiver 1 (2SA1) ASM 344201.

(a) If there is no continuity:

(b) If there is continuity:

do a check of the wiring between the RA transmission antenna 1 (6SA1) and the RA transceiver 1 (2SA1) ASM 344201.

1 If there is no continuity:

2 If there is continuity:

a If the fault continues:

Subtask 34-42-00-740-077-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:09 UTC