Installation of the Magnetic Level-Indicator Lower-Housing

TASK 28-43-23-400-002-A
Installation of the Magnetic Level-Indicator Lower-Housing

WARNING: MAKE SURE THAT THE FLIGHT CONTROL SAFETY-LOCKS AND THE WARNING NOTICES ARE IN POSITION.

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

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

FIN: 91QM

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	SAFETY BARRIER(S)
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 0.495 and 0.405 m.daN (43.81 and 35.84 lbf.in )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.06AEA1)	Polysulfide Sealant-Low Adhesion Brushable -
(Material No.08BAA9)	Non Aqueous Cleaner-General - -
(Material No.14QFB1)	Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
191JB, 195BB, 196BB

D. Referenced Information

REFERENCE	DESIGNATION
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 21-52-22-000-001-A	Removal of the Fan Plenum Chamber
TASK 21-52-22-400-001-A	Installation of the Fan Plenum Chamber
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 28-43-23-000-001-A	Removal of the Magnetic Level-Indicator Rod
TASK 28-43-23-400-001-A	Installation of the Magnetic Level-Indicator Rod
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
TASK 32-12-00-410-001-A	Close the Main Gear Doors after Access
Magnetic Level Indicator 91QM - Lower Assembly Detail ** ON A/C NOT FOR ALL
Magnetic Level Indicator 91QM - Lower Assembly Detail ** ON A/C NOT FOR ALL
Concession for 91QM ** ON A/C NOT FOR ALL
Magnetic Level Indicator 91QM - Lower Assembly Detail with Shim ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-43-23-941-061-A

A. Safety Precautions

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

(1) You must obey the fuel safety procedures when you do work on the fuel system (Ref. AMM TASK 28-00-00-910-001).
(2) Make sure that the SAFETY BARRIER(S) are in position.
(3) Make sure that the WARNING NOTICE(S) in position to tell persons not to operate the landing gear and the related doors.

Subtask 28-43-23-860-050-A

B. Aircraft Maintenance Configuration
(1) Make sure that the main gear doors are open (Ref. AMM TASK 32-12-00-010-001).
(2) Make sure that the 460005835 SLEEVE - GROUND LOCK in on the applicable main gear door actuator.
(3) Make sure that the left-hand plenum chamber, 10HM5 has been removed (Ref. AMM TASK 21-52-22-000-001).
(4) Make sure that the MLI rod has been removed from the MLI lower housing (Ref. AMM TASK 28-43-23-000-001).

4. Procedure
Subtask 28-43-23-420-062-A

A. Preparation for Installation
(1) Clean the component interfaces and the adjacent areas with a Textile-Lint free Cotton - (Material No.14SBA1) made moist with Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Make sure that the parts retained from the removed component are clean and in the correct condition.

Subtask 28-43-23-420-059-A ** ON A/C NOT FOR ALL

B. Installation of the Magnetic Level-Indicator Lower-Housing 91QM
(1) If MLI lower housing part number 3508802-29 is to be installed, continue as follows:
(a) Carefully install the MLI lower housing (7) through the belly fairing skin. Do not cause damage to the bonding strap (11).
(b) Attach the threaded bush (1) to the center body assembly. Do not tighten the threaded bush (1) at this step.
(c) Attach the MLI lower housing (7) to the belly fairing skin with the screws (6).
(d) Attach the bonding strap (2) to the MLI lower housing (7) with:

the screw (3)
the shim (5)
the washer (4) (Ref. AMM TASK 20-28-00-912-802).

(e) Attach the bonding strap (11) to the bracket (10) with:

the bolt (13)
the washers (9) and (12)
the nut (8) (Ref. AMM TASK 20-28-00-912-802).

(f) TORQUE the threaded bush (1) to between 0.495 and 0.405 m.daN (43.81 and 35.84 lbf.in )

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.

(g) Safety the threaded bush (1) to the center body assembly with 14QFB1Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -.
(2) If MLI lower housing part number FRH050001-2 is to be installed, continue as follows:
(a) Carefully install the MLI lower housing (7) through the belly fairing skin.
(b) Attach the MLI lower housing (7) to the belly fairing skin with the screws (6).

NOTE: Make sure that the forward direction arrow on the bottom of the housing (7) points in the correct direction.

the screw (3)

the shim (5)

the washer (4) (Ref. AMM TASK 20-28-00-912-802).

Subtask 28-43-23-420-059-C ** ON A/C NOT FOR ALL

B. Installation of the Magnetic Level-Indicator Lower-Housing 91QM
(1) Carefully install the MLI lower housing (1) through the belly fairing skin.
(2) Attach the MLI lower housing (1) to the belly fairing skin with the screws (5).
(3) Attach the bonding strap (2) to the MLI lower housing (1) with:

the screw (3)
the washer (4) (Ref. AMM TASK 20-28-00-912-802).

Subtask 28-43-23-420-059-F ** ON A/C NOT FOR ALL

B. Installation of the Magnetic Level-Indicator Lower-Housing 91QM

Concession for 91QM ** ON A/C NOT FOR ALL

(1) Apply Polysulfide Sealant-Low Adhesion Brushable - (Material No.06AEA1) on the shim (14).
(2) Install the shim (14) on the MLI lower housing (7).
(3) Carefully install the MLI lower housing (7) through the belly fairing skin. Do not cause damage to the bonding strap (11).
(4) Attach the threaded bush (1) to the center body assembly. Do not tighten the threaded bush (1) at this step.
(5) Attach the MLI lower housing (7) to the belly fairing skin with the screws (6).
(6) Attach the bonding strap (2) to the MLI lower housing (7) with:

the screw (3)
the shim (5)
the washer (4) (Ref. AMM TASK 20-28-00-912-802).

(7) Attach the bonding strap (11) to the bracket (10) with:

the bolt (13)
the washers (9) and (12)
the nut (8) (Ref. AMM TASK 20-28-00-912-802).

(8) TORQUE the threaded bush (1) to between 0.495 and 0.405 m.daN (43.81 and 35.84 lbf.in )

(9) Safety the threaded bush (1) to the center body assembly with 14QFB1Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -.
(10) Make sure the dimensions around the shim (14) are not more than 2 mm (0.0787 in.).

Subtask 28-43-23-420-059-H ** ON A/C NOT FOR ALL

B. Installation of the Magnetic Level-Indicator Lower-Housing 91QM
(1) Shim(s) (8) inspection;
(a) If shim(s) (8) were removed during the disassembly procedure and are serviceable, use shim(s) (8) for installation.
(b) If shim(s) (8) were removed during the disassembly procedure and are unserviceable, replace with new shim(s) (8) of the same dimension.
(2) Apply Polysulfide Sealant-Low Adhesion Brushable - (Material No.06AEA1) on the shim(s) (8).
(3) Install the shim(s) (8) on the MLI lower housing (7).
(4) Carefully install the MLI lower housing (7) through the belly fairing skin.
(5) Attach the MLI lower housing (7) to the belly fairing skin with the screws (6).

NOTE: Make sure that the forward direction arrow on the bottom of the housing (7) points in the correct direction.

(6) Measure the clearance between the MLI lower housing (7) and the panel. The MLI lower housing (7) must extend between 1mm and 5mm through the panel.
(7) If the extension of the MLI lower housing (7) is not between 1mm and 5mm select the shim(s) (8) to get the measurement between 1mm and 5mm.
(8) Attach the bonding strap (2) to the MLI lower housing (7) with:

the screw (3)
the shim (5)
the washer (4) (Ref. AMM TASK 20-28-00-912-802).

5. Close-up
Subtask 28-43-23-410-054-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the MLI rod (Ref. AMM TASK 28-43-23-400-001).
(3) Install the fan plenum chamber, 10HM5 (Ref. AMM TASK 21-52-22-400-001).
(4) Install the access panels 191JB and 195BB and/or 196BB.
(5) Close the main landing gear doors (Ref. AMM TASK 32-12-00-410-001).

Subtask 28-43-23-942-052-A

B. Removal of Equipment
(1) Remove the safety barriers.
(2) Remove the WARNING NOTICE(S).
(3) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.02 06:18:14 UTC