Removal of the Weather-Radar Antenna Assembly

TASK 34-41-11-000-004-A
Removal of the Weather-Radar Antenna Assembly

WARNING: MOVE THE RADAR ANTENNA ASSEMBLY CAREFULLY TO PREVENT INJURY TO PERSONS AND DAMAGE TO EQUIPMENT. THE RADAR ANTENNA ASSEMBLY (ANTENNA/DRIVE) WEIGHS APPROXIMATELY 15kg (33lb).

CAUTION: DO NOT USE THE LOCALIZER ANTENNA AT THE BOTTOM OF THE RADOME AS A SUPPORT.

ZONE: 110
FIN: 11SQ ** ON A/C NOT FOR ALL
FIN: 7SQ ** ON A/C NOT FOR ALL

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	ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE
No specific	1	BAG - PLASTIC
No specific	AR	CAP - BLANKING
No specific	1	CONTAINER - CLEAN, APPLICABLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
110	RADOME (NOSE CONE TO FR 1)
110AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 53-15-11-010-001-A	Opening of the Radome
Weather-Radar Antenna Assembly ** ON A/C NOT FOR ALL
Radar Antenna ** ON A/C NOT FOR ALL
Weather-Radar Antenna Assembly ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 34-41-11-865-059-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	COM NAV/RADAR/1	5SQ1	K13

Subtask 34-41-11-010-053-A ** ON A/C NOT FOR ALL

B. Get Access
(1) In the cockpit, put the WARNING NOTICE(S) on the center pedestal to tell persons not to operate the weather radar system.
(2) Put the ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE in position below the radome at zone 110.
(3) Open radome 110AL (Ref. AMM TASK 53-15-11-010-001).

4. Procedure
Subtask 34-41-11-020-056-A ** ON A/C NOT FOR ALL

A. Removal of the Antenna

NOTE: During the removal of the antenna, two persons are necessary. One person must hold the antenna and the other person must hold the position indicator (14) (to prevent damage to the drive caused by the fast movement of the counterbalance spring).

(1) Remove the screws (21) and the lockwashers (20) which connect the flange of the wave guide (17) to the antenna (18).
(2) Remove the screws (15) and the lockwashers (16) which connect the ring mount (19) to the antenna (18) and remove the antenna (18).
(3) Slowly release the position indicator (14).
(4) Put the antenna (18) in a plastic bag and in a correct container.

Subtask 34-41-11-020-057-A ** ON A/C NOT FOR ALL

B. Removal of the Antenna Assembly

NOTE: Two persons are necessary for the removal of the antenna drive. One person holds the antenna drive while the other person removes all the bolts.

(1) Disconnect the electrical connector(s) (11).
(2) Removal of the waveguide (5):

CAUTION: BE CAREFUL WHEN HANDLING THE WAVEGUIDE AS DAMAGE CAN OCCUR IF IT IS BENT BEYOND THE MANUFACTURERS LIMITATIONS. ENSURE THAT NO DEBRIS ENTERS THE WAVEGUIDE FROM THE OPEN END(S) WHEN REMOVED.

(a) Release the quick-disconnect attach (4).
(b) Disconnect the flange of the waveguide (5) from the antenna drive (13).
(c) Remove and discard the O-ring (6).
(d) Remove the screw (26) and the washer (25).
(e) Remove the clamp (27) and the two half-bushings (28) from the waveguide (5).

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(f) Removal of the lockwires:

Cut and discard the lockwires that attach the four bolts (23).

(g) Remove the four bolts (23) and the four washers (24).
(h) Disconnect the waveguide (5) from the flange (22).
(i) Remove and discard the O-ring (29).
(j) Remove the waveguide (5).
(3) Put the CAP - BLANKING on the disconnected connectors (11) and (12) and on the disconnected ends of the waveguide.
(4) Remove the two bottom bolts (10) and the washers (9).
(5) Remove the two top bolts (1) and the washers (2).
(6) Remove the antenna drive (13) and put it in a plastic bag and in a correct container.

Subtask 34-41-11-020-056-B ** ON A/C NOT FOR ALL

C. Removal of the Weather Radar Antenna
(1) One person must hold the antenna during its removal.

(2) Remove and discard the lockwire and loosen the bolts (14).
(3) Remove the antenna (17) and put it in the BAG - PLASTIC and in the CONTAINER - CLEAN, APPLICABLE.

Subtask 34-41-11-020-057-B ** ON A/C NOT FOR ALL

D. Removal of the Weather-Radar Antenna Assembly

NOTE: Two persons are necessary for the removal of the antenna drive. One person holds the antenna drive while the other person removes all the bolts.

(1) Disconnect the electrical connector(s) (11).
(2) Loosen the quick-disconnect clamp (8) and disconnect the wave guide (4) from the antenna drive (1).
(3) Remove and discard the O-ring (3).
(4) Put CAP - BLANKING on the disconnected connectors (11) and (12), and on the flange of the wave guide (4).
(5) Remove the bottom bolts (10) and the washers (9).
(6) Loosen the top bolts (5) and the washers (6), but do not remove them.
(7) Lift the antenna drive (1) until the holes (2) are at the same level as the top bolts (5) and then pull it carefully.
(8) Remove the antenna drive (1) and put it in a plastic bag and in a correct container.

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