Deactivation of the Radio Altimeter (RA) Systems (FAA Only)

TASK 34-42-00-040-801-A
Deactivation of the Radio Altimeter (RA) Systems (FAA Only)

ZONE: 210

1. Reason for the Job
MMEL 34-42-01
RADIO ALTIMETER (RA) SYSTEMS (FAA ONLY)
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power

3. Job Set-up
Subtask 34-42-00-861-050-A

A. Aircraft Maintenance Configuration
(1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).

Subtask 34-42-00-865-063-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	COM NAV/RAD ALTM/2	1SA2	K12
121VU	COM NAV/RAD ALTM/1	1SA1	K11

4. Procedure
Subtask 34-42-00-040-050-A

A. Deactivation of the RA Systems
(1) If RA 1 is inoperative, do the step that follow:
(a) On circuit breaker panel 121VU:
1 Open, safety and tag this(these) circuit breaker(s):

1SA1.

(2) If RA 2 is inoperative, do the step that follow:
(a) On circuit breaker panel 121VU:
1 Open, safety and tag this(these) circuit breaker(s):

1SA2.

5. Close-up
Subtask 34-42-00-942-050-A

A. Put the aircraft back to its initial configuration.
(1) Make an entry in the logbook.
(2) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(3) Make sure that the work area is clean and clear of tools and other items.

[Rev.10 from 2021] 2026.04.02 06:23:23 UTC