Installation of the Overpressure Protector

TASK 28-12-41-400-001-A
Installation of the Overpressure Protector

WARNING: THIS PROCEDURE USES A FUEL SYSTEM ITEM THAT IS IN A CATEGORY KNOWN AS A CRITICAL DESIGN CONFIGURATION CONTROL LIMITATION (CDCCL). CDCCL IDENTIFIES AN ITEM THAT CAN BE THE SOURCE OF A POSSIBLE FUEL TANK IGNITION. YOU MUST KEEP ALL CDCCL ITEMS IN THE APPROVED CONFIGURATION. DAMAGE, WEAR OR CHANGES TO A CDCCL ITEM CAN CAUSE A POSSIBLE FUEL TANK EXPLOSION.

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: 46QM
FIN: 47QM

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 4M (13 FT)
No specific	AR	SAFETY BARRIER(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.01ABA1)	Turbine Fuel-- Kerosene -
(Material No.03FAB1)	Mineral Oil base Grease-- Vaseline or Petrolatum -
(Material No.06ABA1)	Polysulfide Sealant-Fuel Tank Brushable -
(Material No.08BAA9)	Non Aqueous Cleaner-General - -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [46QM] (PROTECTOR-OVERPRESSURE, L VENT SURGE TK)
550CB
FOR [47QM] (PROTECTOR-OVERPRESSURE, R VENT SURGE TK)
650CB

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
3	O-RINGS	AIPC 28-12-45-01-030
6	O-RINGS	AIPC 28-12-45-01-030
2	O-RING	AIPC 28-12-45-01-040
9	O-RING	AIPC 28-12-45-01-040

E. Referenced Information

REFERENCE	DESIGNATION
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 28-10-00-910-001-A	Safety Procedures When You Do Work in a Fuel Tank
TASK 28-10-00-910-002-A	Access to the Fuel Tanks and the Work Areas
TASK 28-12-45-000-001-A	Removal of the Panel Assembly
TASK 28-12-45-400-002-A	Installation of the Panel Assembly
TASK 28-12-47-200-001-A	Visual Check of NACA Intake for Signs of Blockage
TASK 28-25-00-650-003-A	To Drain Remaining Fuel from the Wing Tanks and the Center Tank
TASK 28-25-00-650-003-A-01	To Drain Remaining Fuel from the Wing Tanks and the Center Tank
Overpressure Protector - Vent Surge Tank. ** ON A/C NOT FOR ALL
Overpressure Protector - Vent Surge Tank. ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-12-41-941-066-A

A. Safety Precautions

WARNING: BEFORE YOU DO WORK IN OR NEAR A FUEL TANK, MAKE SURE THAT YOU OBEY ALL THE SAFETY PROCEDURES. THIS WILL PREVENT INJURY TO PERSONS AND/OR DAMAGE TO THE AIRCRAFT.

(1) You must obey the fuel safety procedures when you do work in the fuel tank (Ref. AMM TASK 28-10-00-910-001).
(2) Make sure that the SAFETY BARRIER(S) are in position.

Subtask 28-12-41-860-050-A

B. Aircraft Maintenance Configuration
(1) Make sure that the remaining fuel has been drained from the applicable surge tank (Ref. AMM TASK 28-25-00-650-003).
(2) Make sure that the ACCESS PLATFORM 4M (13 FT) is below the applicable zone 550(650).
(3) Make sure that the applicable panel assembly 550CB(650CB) is removed (Ref. AMM TASK 28-12-45-000-001) and (Ref. AMM TASK 28-10-00-910-002).

4. Procedure
Subtask 28-12-41-420-053-A ** ON A/C NOT FOR ALL

A. Preparation for Installation
(1) Clean the component interface and/or the adjacent area 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.
(4) Lubricate the new AIPC 28-12-45-01-040 O-RING (2) and the new AIPC 28-12-45-01-030 O-RINGS (6) with Turbine Fuel-- Kerosene - (Material No.01ABA1) or Mineral Oil base Grease-- Vaseline or Petrolatum - (Material No.03FAB1) .

Subtask 28-12-41-420-050-A ** ON A/C NOT FOR ALL

B. Installation of the Overpressure Protector 46QM (47QM)
(1) Put the bolts (4) and the new O-rings (6) in position.
(2) Install the new O-ring (2) on the overpressure protector (1).
(3) Put the overpressure protector (1) in position on the access panel (3).
(4) Make sure that the dowel engages in the dowel hole (5).
(5) Install the nuts (7).
(6) Align the hole in the overpressure protector (1) with the hole in the access panel (3).
(7) Tighten the bolts (4).
(8) Make sure that the overpressure protector (1) is correctly bonded to the access panel (3):

WARNING: THIS INSTRUCTION IS APPLICABLE TO A CRITICAL DESIGN CONFIGURATION CONTROL LIMITATION (CDCCL) ITEM. CAREFULLY OBEY ALL GIVEN INSTRUCTIONS WHEN YOU DO THIS STEP. IF YOU DO NOT OBEY THESE INSTRUCTIONS, A DANGEROUS CONDITION CAN OCCUR THAT CAN CAUSE A POSSIBLE FUEL TANK EXPLOSION.

(a) Do a bonding check between the overpressure protector and the access panel (Ref. AMM TASK 20-28-00-912-802). The bonding resistance must be less than 10 milliohms.
(9) Apply Polysulfide Sealant-Fuel Tank Brushable - (Material No.06ABA1) over the nuts (7) and the ends of the bolts (4).

Subtask 28-12-41-420-053-B ** ON A/C NOT FOR ALL

C. Preparation for Installation
(1) Clean the component interface and/or the adjacent area 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.
(4) Lubricate the new AIPC 28-12-45-01-040 O-RING (9) and the new AIPC 28-12-45-01-030 O-RINGS (3) with Turbine Fuel-- Kerosene - (Material No.01ABA1) or Mineral Oil base Grease-- Vaseline or Petrolatum - (Material No.03FAB1) .

Subtask 28-12-41-420-050-B ** ON A/C NOT FOR ALL

D. Installation of the Overpressure Protector 46QM (47QM)
(1) Put the bolts (5) and the new O-rings (3) in position.
(2) Align the hole in the vortex generator (7) with the hole in the access panel (4).
(3) Put the bolts (6), the vortex generator (7) and the new O-rings (3) in position.
(4) Install the new O-ring (9) on the overpressure protector (1).
(5) Put the overpressure protector (1) in position on the access panel (4).
(6) Make sure the dowel engages in the dowel hole (8).
(7) Install the nuts (2).
(8) Align the hole in the overpressure protector (1) with the hole in the access panel (4).
(9) Tighten the bolts (5) and (6).
(10) Make sure that the overpressure protector (1) is correctly bonded to the access panel (4):

(a) Do a bonding check between the overpressure protector and the access panel (Ref. AMM TASK 20-28-00-912-802). The bonding resistance must be less than 10 milliohms.
(11) Apply Polysulfide Sealant-Fuel Tank Brushable - (Material No.06ABA1) over the nuts (2) and the ends of the bolts (5) and (6).

Subtask 28-12-41-210-064-A

E. Visual Inspection
(1) Do a visual inspection of the applicable NACA vent intake (Ref. AMM TASK 28-12-47-200-001).

5. Close-up
Subtask 28-12-41-410-054-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the wing access panel (Ref. AMM TASK 28-12-45-400-002):

(a) FOR [46QM] (PROTECTOR-OVERPRESSURE, L VENT SURGE TK)

Install 550CB.

(b) FOR [47QM] (PROTECTOR-OVERPRESSURE, R VENT SURGE TK)

Install 650CB.

Subtask 28-12-41-942-053-A

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

[Rev.10 from 2021] 2026.04.02 06:17:09 UTC