Loss of the Altitude Bus 2 of the RA Transceiver 1 Identified by the EIS3

TASK 34-42-00-810-810-A
Loss of the Altitude Bus 2 of the RA Transceiver 1 Identified by the EIS3

1. Possible Causes

XCVR-RA, 1 [2SA1]
wiring of the ALTITUDE BUS 2 from the RA transceiver 1 (2SA1) to the first terminal block

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-60-00-740-002	Perform Electronic Instrument System (EIS) Input Test
AMM 31-60-00-740-007	GROUND SCANNING Test of the DMC
ASM 344201
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 34-42-00-865-059-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 34-42-00-740-064-A ** ON A/C NOT FOR ALL

B. Test
(1) Do the EIS input test AMM 31-60-00-740-002.

Subtask 34-42-00-740-064-B ** ON A/C NOT FOR ALL

B. Test
(1) Do the Ground Scanning Test of the DMC AMM 31-60-00-740-007

4. Fault Isolation
Subtask 34-42-00-810-061-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message DMC3 : NO RA1 DATA:

(1) If the fault continues:

do a check and repair the wiring of the ALTITUDE BUS 2 from the RA transceiver 1 (2SA1) to the first terminal block ASM 344201.

Subtask 34-42-00-810-061-B ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message RA1(2SA1)/DMC3(1WT3):

(1) If the fault continues:

do a check and repair the wiring of the ALTITUDE BUS 2 from the RA transceiver 1 (2SA1) to the first terminal block ASM 344201.

Subtask 34-42-00-740-065-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:33:07 UTC