Installation of the DME Antenna

TASK 34-51-11-400-002-A
Installation of the DME Antenna

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

ZONE: 121
ZONE: 127
FIN: 3SD1
FIN: 3SD2

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	SCRAPER - NON METALLIC
No specific	AR	TAPE - MASKING

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.04QAB2)	Coating_- Flexible Structure
(Material No.04TMB2)	Varnish-- Electrical Bonding Structure
(Material No.06AAB1)	Polysulfide Sealant-General Purpose Fillet -
(Material No.06ABF1)	Polysulfide Sealant-Fuel Tank Quick Curing -
(Material No.06AEB2)	Polysulfide Sealant-Low Adhesion Fillet Structure
(Material No.08BAA9)	Non Aqueous Cleaner-General - -
(Material No.14DBB1)	Release Agent-- Liquid Wax -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
121	AVIONICS COMPARTMENT
127	REAR AVIONIC COMPARTMENT

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
6	O-RING SEAL	AIPC 34-51-11-01-010

E. Referenced Information

REFERENCE	DESIGNATION
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 34-51-00-710-001-A	Operational Test of the DME
TASK 34-51-00-720-001-A	Functional Test of the DME
TASK 51-76-11-300-001-A	Repair of the Sealing
DME Antenna

3. Job Set-up
Subtask 34-51-11-865-053-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 3SD1 (ANTENNADME, 1)
49VU	NAV/DME/1	1SD1	G14
FOR FIN: 3SD2 (ANTENNADME, 2)
121VU	COM NAV/DME/2	1SD2	K06

4. Procedure

WARNING: DO NOT GET THE FLUID ON YOUR SKIN OR IN YOUR EYES. IF YOU DO:

FLUSH IT AWAY WITH CLEAN WATER
GET MEDICAL AID.

Subtask 34-51-11-914-053-A

CAUTION: AFTER THREE DAYS OF FLIGHT WITHOUT SEALANT, DO THE FULL INSTALLATION OF THE ANTENNA:

REMOVE THE ANTENNA
CLEAN THE FUSELAGE AND ANTENNA SURFACES AND REMOVE ALL SIGNS OF HUMIDITY.

IF YOU DO NOT DO THIS, WATER CAN GO INTO THE STRUCTURE AND CORROSION CAN OCCUR.

CAUTION: AFTER TEN DAYS OF FLIGHT WITH INTERPOSITION SEALANT OR A GEL/ SILICON GASKET, DO THESE STEPS:

CLEAN THE AREA AROUND THE ANTENNA, AND
APPLY A SEALANT BEAD AROUND THE ANTENNA AND/OR SEALANT ON THE HEADS OF THE SCREWS.

IF YOU DO NOT DO THIS, WATER CAN GO INTO THE STRUCTURE AND CORROSION CAN OCCUR.

A. Aircraft Antenna Sealant-Exemption
Obey the indications given in the table that follows if it is not possible to:

Apply the sealant.
Let the sealant cure during the applicable curing time.

This table gives the time limits that are applicable for the sealant installation on the Distance Measuring Equipment (DME) antenna.
These limits are adapted to:

The antenna installation configuration
The antenna location
The sensitive condition of the antenna to water infiltration
The available condition of the sealant.

Configuration of the antenna installation	If the airline has sealant but cannot wait until the sealant is cured	If the airline has no sealant available
Sealant between the antenna and the fuselage (interposition sealant): Sealing bead around the antenna Sealant on the heads of the screws O-ring at the antenna connector level.	It is permitted to fly for a maximum of ten days without the sealing bead around the antenna if the interposition sealant is applied and the O-ring is installed. It is permitted to fly for a maximum of ten days without the sealant on the heads of the screws.	It is permitted to fly for a maximum of three days without the sealant (interposition sealant, sealing bead and sealant on the heads of the screws) if the O-ring is installed.

Configuration of the antenna installation

If the airline has sealant but cannot wait until the sealant is cured

If the airline has no sealant available

Sealant between the antenna and the fuselage (interposition sealant):

Sealing bead around the antenna
Sealant on the heads of the screws
O-ring at the antenna connector level.

It is permitted to fly for a maximum of ten days without the sealing bead around the antenna if the interposition sealant is applied and the O-ring is installed.

It is permitted to fly for a maximum of ten days without the sealant on the heads of the screws.

It is permitted to fly for a maximum of three days without the sealant (interposition sealant, sealing bead and sealant on the heads of the screws) if the O-ring is installed.

NOTE: When there is no sealing bead, there is a risk of aerodynamic noise.

Subtask 34-51-11-420-050-A

B. Installation of the DME Antenna
(1) Remove the used sealant from the fuselage with the Non Aqueous Cleaner-General - - (Material No.08BAA9) and the SCRAPER - NON METALLIC.
(a) If you install the same antenna, clean it with a Textile-Lint free Cotton - (Material No.14SBA1) .
(2) Do an inspection of the component interfaces and the adjacent area.
(a) Make sure that the attachment screw-head recesses of the antenna have no signs of paint, corrosion or sealant. You will use the attachment screws to do the electrical bonding of the antenna.
(3) Apply the TAPE - MASKING to:

The structure (1)
The edge of the antenna (4)
The screw holes
The hole for the antenna connector.

(4) Apply the Release Agent-- Liquid Wax - (Material No.14DBB1) on the antenna (4) mount and on the fuselage (1).
(5) Apply the Polysulfide Sealant-Low Adhesion Fillet Structure (Material No.06AEB2) on the antenna (4) mount and on the fuselage (1) (Ref. AMM TASK 51-76-11-300-001).
(a) Make sure that there is no sealant in the screw holes.
(6) Remove the blanking caps from the coaxial connectors (2) and (3).
(7) Install the new AIPC 34-51-11-01-010 O-RING SEAL (6).
(8) Connect the coaxial connector (2) to the antenna connector (3).
(9) Put the antenna (4) in position on the fuselage (1).
(10) Attach the antenna (4) with the screws (5).
(11) Remove the sealant which is not necessary with the SCRAPER - NON METALLIC.
(12) Make sure that the bonding contact resistance between the antenna (4) and the fuselage structure (1) is not more than 5 milliohms (Ref. AMM TASK 20-28-00-912-802).
(13) Apply a sealing bead with the Polysulfide Sealant-General Purpose Fillet - (Material No.06AAB1) , or as an alternative the Polysulfide Sealant-Fuel Tank Quick Curing - (Material No.06ABF1) , around the antenna (4) (Ref. AMM TASK 51-76-11-300-001).
(14) Apply the Polysulfide Sealant-General Purpose Fillet - (Material No.06AAB1) , or as an alternative the Polysulfide Sealant-Fuel Tank Quick Curing - (Material No.06ABF1) , on the heads of the screws (5).
(15) Make the contour of the screws (5) and the antenna (4) smooth.
(16) Apply the Coating_- Flexible Structure (Material No.04QAB2) to the sealant around the base of the antenna (4).

NOTE: It is not mandatory to paint the sealant around the base of the antenna and on the heads of the screws.

(17) Apply the Varnish-- Electrical Bonding Structure (Material No.04TMB2) to the sealant on the heads of the screws (5).

Subtask 34-51-11-865-054-A

C. 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: 3SD1 (ANTENNADME, 1)
49VU	NAV/DME/1	1SD1	G14
FOR FIN: 3SD2 (ANTENNADME, 2)
121VU	COM NAV/DME/2	1SD2	K06

Subtask 34-51-11-720-050-A

D. Do the functional test of the DME with tool (Ref. AMM TASK 34-51-00-720-001) or the operational test of the DME without tool (Ref. AMM TASK 34-51-00-710-001).

5. Close-up
Subtask 34-51-11-410-050-A

A. Make sure that the work area is clean and clear of tools and other items.

[Rev.10 from 2021] 2026.04.01 01:02:33 UTC