Removal of the Radio Altimeter Antenna

TASK 34-42-11-000-001-A
Removal of the Radio Altimeter Antenna

ZONE: 150
FIN: 5SA1
FIN: 5SA2
FIN: 6SA1
FIN: 6SA2

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

REFERENCE	QTY	DESIGNATION
No specific	AR	CAP - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	SCRAPER - NON METALLIC

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
150	AFT CARGO COMPARTMENT FWD PRESS BULKHEAD TO AFT BULKHEAD OF AFT CARGO COMPARTMENT

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
Radio Altimeter Antennas with Gasket for Water Ingress Protection

3. Job Set-up
Subtask 34-42-11-861-050-A

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

Subtask 34-42-11-865-050-A

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 5SA1 (ANTENNARA RCPTN, 1)
121VU	COM NAV/RAD ALTM/1	1SA1	K11
FOR FIN: 6SA1 (ANTENNARA XMSN, 1)
121VU	COM NAV/RAD ALTM/1	1SA1	K11
FOR FIN: 5SA2 (ANTENNARA RCPTN, 2)
121VU	COM NAV/RAD ALTM/2	1SA2	K12
FOR FIN: 6SA2 (ANTENNARA XMSN, 2)
121VU	COM NAV/RAD ALTM/2	1SA2	K12

4. Procedure
Subtask 34-42-11-020-059-B

A. Removal of the Radio Altimeter Antenna with Gasket and Water Ingress Protection

Radio Altimeter Antennas with Gasket for Water Ingress Protection

NOTE: If you do not have installed the gasket and the sleeves for water ingress protection, the following steps are not applicable.

NOTE: This procedure is the same for the radio altimeter antennas 5SA1, 5SA2, 6SA1, 6SA2.

(1) Remove the sealant from the heads of the screws (5) with a SCRAPER - NON METALLIC.
(2) Remove the attachment screws (5) from the antenna (4).
(3) Pull the antenna (4) carefully away until you can see the shrink sleeve (9).
(4) Remove the sealant from the shrink sleeve (9) with a SCRAPER - NON METALLIC.
(5) Carefully remove the shrink sleeves (9) and (10) from the connectors (2) and (3).
(6) Make sure that the shrink sleeve (8) is not removed.
(7) Temporarily attach the coaxial connector (2) on the external side of the fuselage structure (1).

NOTE: The coaxial connector (2) could move inside the hole, if is not blocked.

(8) Disconnect the coaxial connector (2) from the antenna connector (3).
(9) Remove the antenna (4) from the fuselage structure (1).
(10) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(11) Do an inspection of the component interfaces and the adjacent area.
(12) Make sure that:

There is no rust on the antenna connector (3).
There is no erosion, corrosion or scratches at the bottom of the antenna (4).
There are no paint or paint flaking at the bottom antenna (4) area.
The alignment marks are fully visible.

(13) Discard all parts with damages or stains of paint and use new ones.
(14) Remove the O-ring (6) from the antenna (4).

NOTE: If the O-ring (6) is in a good condition you can keep it for the subsequent installation.

(15) Remove and discard the gasket (7) from the antenna (4).

[Rev.10 from 2021] 2026.04.01 01:01:35 UTC