Installation of the Radio Altimeter-Transceiver Fan

TASK 34-42-45-400-001-A
Installation of the Radio Altimeter-Transceiver Fan

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 152
FIN: 3SA1
FIN: 3SA2

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)

B. Consumable Materials

REFERENCE	DESIGNATION
No specific	CABLE TIES

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
152	AFT CARGO COMPARTMENT
152HW

D. Referenced Information

REFERENCE	DESIGNATION
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
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
TASK 34-42-00-750-001-A	Operational Check and Detailed Inspection for Contamination of Radio Altimeter Fan
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
Radio Altimeter-Transceiver Fan

3. Job Set-up
Subtask 34-42-45-860-050-A

A. Aircraft Maintenance Configuration
(1) Make sure that the ground service network is energized
(Ref. AMM TASK 24-42-00-861-001)
(2) Make sure that the Aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001) is open.
(3) Make sure that the access panel 152HW is removed.
(4) Make sure that the ACCESS PLATFORM 2M (6 FT) is in position at the Aft cargo door 826.

Subtask 34-42-45-865-051-A

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 3SA1 (FANRA XCVR1)
121VU	COM NAV/RAD ALTM/1	1SA1	K11
FOR FIN: 3SA2 (FANRA XCVR2)
121VU	COM NAV/RAD ALTM/2	1SA2	K12

4. Procedure
Subtask 34-42-45-420-050-B

A. Installation of the Radio Altimeter-Transceiver Fan
(1) Clean the component interfaces and the adjacent area.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Remove the CAP-BLANKING from each electrical connector and receptacle.
(4) Make sure that all the electrical connections are clean and in the correct condition.
(5) Install the blower (7) with the washers (5), bolts (8) and nuts (4) on the cool-air inlet (6).
(a) Make sure that the air flow arrow on the blower (7) points to the radio altimeter transceiver.
(6) Tighten the nuts (4).
(7) Connect the electrical connections (10).
(8) Install the cool-air inlet (6) with the washers (11) and the bolts (12) on the plate (1).
(9) Tighten the bolts (12).
(10) Install the plate (1) with the washers (2) and the screws (3) on the structure.
(11) Tighten the screws (3).
(12) Do a check of the maximum bonding value between the screws (3) and the structure (Ref. AMM TASK 20-28-00-912-802):

Make sure that the maximum bonding value is not more than ten milliohms.

(13) Connect the electrical connector (9).
(14) Install the CABLE TIES.

Subtask 34-42-45-865-052-A

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 3SA1 (FANRA XCVR1)
121VU	COM NAV/RAD ALTM/1	1SA1	K11
FOR FIN: 3SA2 (FANRA XCVR2)
121VU	COM NAV/RAD ALTM/2	1SA2	K12

Subtask 34-42-45-750-050-A

C. Do the fan test of the radio altimeter system (Ref. AMM TASK 34-42-00-750-001).

5. Close-up
Subtask 34-42-45-410-050-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the access panel 152HW.
(3) Remove the access platform(s).
(4) Close the AFT Cargo Door 826 (Ref. AMM TASK 52-30-00-860-002).

Subtask 34-42-45-862-050-A

B. De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001)

[Rev.10 from 2021] 2026.04.02 07:15:10 UTC