Installation of the Weather-Radar Antenna Assembly

TASK 34-41-11-400-014-A
Installation 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 THE WORK IN AN AREA THAT HAS PROTECTION FROM WEATHER. WIND CAN CAUSE SUDDEN UNWANTED MOVEMENT OF THE ANTENNA, WITH A RISK OF DAMAGE. RAIN CAN GO INTO THE RADOME AREA AND CAUSE INCORRECT WEATHER DATA ON THE ND.

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	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 0.40 and 0.34 m.daN (35.40 and 30.09 lbf.in )
No specific	Torque wrench: range to between 3.87 and 3.22 m.daN (28.54 and 23.75 lbf.ft )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.04TMB2)	Varnish-- Electrical Bonding Structure

C. Work Zones and Access Panels

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

D. Referenced Information

REFERENCE	DESIGNATION
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 34-41-00-740-002-A	BITE Test of the Weather Radar
TASK 34-41-51-400-001-A	Installation of the Transmitter Receiver Unit
TASK 53-15-11-010-001-A	Opening of the Radome
TASK 53-15-11-410-001-A	Closing of the Radome
Weather Antenna Drive-Unit
Weather Radar Antenna

3. Job Set-up
Subtask 34-41-11-860-064-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Make sure that the WARNING NOTICE(S), which tells persons not to operate the weather radar system, is in position in the cockpit on the center pedestal.
(2) Make sure that the ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE is in position in zone 110 below the radome.
(3) Make sure that the radome 110AL is open (Ref. AMM TASK 53-15-11-010-001).

Subtask 34-41-11-865-083-A ** ON A/C NOT FOR ALL

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

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

4. Procedure
Subtask 34-41-11-420-072-A ** ON A/C NOT FOR ALL

A. Installation of the Antenna Assembly

Weather Antenna Drive-Unit ** ON A/C NOT FOR ALL

NOTE: Two persons are necessary for this procedure. One person holds the antenna while the other installs the screws.

(1) Do a visual inspection and clean the component interface and/or the adjacent area.
(2) Install the two top screws (5) and the two washers (6) and make sure that they are sufficiently loose.
(3) Lift the weather antenna drive-unit (3) up to its support and engage it in the two top screws (5).
(4) Install the two bottom screws (10) and the two washers (9).
(5) TORQUE the screws (5) and (9) to between 3.87 and 3.22 m.daN (28.54 and 23.75 lbf.ft )

.
(6) Prepare for electrical bonding of the weather antenna drive-unit (3) at the bolts (5) and (9) (Ref. AMM TASK 20-28-00-912-802).
(7) Install the Transmitter Receiver Unit (TRU) 1 (7) (Ref. AMM TASK 34-41-51-400-001).
(8) Do an electrical bonding check between the weather antenna drive-unit (3) and the fuselage structure (Ref. AMM TASK 20-28-00-912-802):

Use a MILLIOHMMETER 0,5 OHM MAX, 10 A MAX - MULTIRANGE.
Make sure that the maximum bonding value is less than 5 milliohms.

(9) Apply material:

CAUTION: IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURERS MATERIAL SAFETY DATA SHEETS FOR CONSUMABLE MATERIALS INFORMATION.

(a) Apply layers of Material Varnish-- Electrical Bonding Structure (Material No.04TMB2) to the bolts (5) and (9).

Subtask 34-41-11-420-073-A ** ON A/C NOT FOR ALL

B. Installation of the Antenna Plate

Weather Radar Antenna ** ON A/C NOT FOR ALL

(1) Do a visual inspection and clean the component interface and/or the adjacent area.
(2) Connect the antenna waveguide (4) to the elevation mount waveguide (2) on the weather antenna drive-unit (3) (the two parts of the waveguide are fit into each other).
(3) Attach the antenna (1) to the weather antenna drive-unit (3) with the four screws (5).
(4) TORQUE the four screws (5) to between 0.40 and 0.34 m.daN (35.40 and 30.09 lbf.in )

.
(5) Hold the flat plate and carefully move it in side-to-side and up-down directions to the mechanical stops in each direction. Make sure that there is no resistance to movement.

Subtask 34-41-11-865-084-A ** ON A/C NOT FOR ALL

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

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

Subtask 34-41-11-740-052-A ** ON A/C NOT FOR ALL

D. Do the BITE test of the weather radar system (Ref. AMM TASK 34-41-00-740-002).

5. Close-up
Subtask 34-41-11-410-061-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tool(s) and other items.
(2) Close the radome 110AL (Ref. AMM TASK 53-15-11-410-001).
(3) Remove the access platform(s).
(4) Remove the warning notice(s).

[Rev.10 from 2021] 2026.04.01 01:01:06 UTC