Installation of the Check Valve

TASK 28-12-44-400-004-A
Installation of the Check Valve

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.

FIN: 120QM
FIN: 121QM

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 3M (10 FT)- ADJUSTABLE
No specific	AR	SAFETY BARRIER(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
540AB, 540BZ, 640AB, 640BZ
FOR [120QM] (CHECK VALVE-FUEL DRAIN, L WING TK INR REAR)
540AB
FOR [121QM] (CHECK VALVE-FUEL DRAIN, R WING TK INR REAR)
640AB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 12-11-28-650-003-A	Pressure Refuel with Automatic Control
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 28-25-00-650-001-A	Pressure Defuel
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
TASK 28-25-00-869-001-A	Fuel Transfer
TASK 57-27-11-000-001-A	Removal of the Access Panel
TASK 57-27-11-400-001-A	Installation of the Access Panel
TASK 57-27-12-000-002-A	Removal of the Rib 2 Access Panel 540AZ(640AZ) or 540BZ(640BZ)
TASK 57-27-12-400-002-A	Installation of the Rib 2 Access Panel 540AZ (640AZ) or 540BZ (640BZ)
Check Valve 50QM(51QM) 52QM(53QM) 120QM(121QM) 93QM ** ON A/C NOT FOR ALL
Check Valve 50QM(51QM) 120QM(121QM) 93QM ** ON A/C NOT FOR ALL
FOR [120QM] (CHECK VALVE-FUEL DRAIN, L WING TK INR REAR)
TASK 57-27-11-000-001-A	Removal of the Access Panel
TASK 57-27-11-400-001-A	Installation of the Access Panel
FOR [121QM] (CHECK VALVE-FUEL DRAIN, R WING TK INR REAR)
TASK 57-27-11-000-001-A	Removal of the Access Panel
TASK 57-27-11-400-001-A	Installation of the Access Panel

3. Job Set-up
Subtask 28-12-44-941-068-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 (Ref. AMM TASK 28-10-00-910-001) when you do work in a fuel tank.
(2) Make sure that the SAFETY BARRIER(S) are in position.

Subtask 28-12-44-860-057-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration

Check Valve 50QM(51QM) 52QM(53QM) 120QM(121QM) 93QM ** ON A/C NOT FOR ALL

Check Valve 50QM(51QM) 120QM(121QM) 93QM ** ON A/C NOT FOR ALL

(1) Make sure that the applicable fuel tank is defueled (Ref. AMM TASK 28-25-00-650-001).
(2) Make sure that the remaining fuel has been drained from the applicable fuel tank (Ref. AMM TASK 28-25-00-650-003).
(3) Make sure that the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE is below the applicable access panel 540AB(640AB).
(4) Make sure that the applicable access panel is removed (Ref. AMM TASK 28-10-00-910-002), (Ref. AMM TASK 57-27-11-000-001):
(a) FOR [120QM] (CHECK VALVE-FUEL DRAIN, L WING TK INR REAR)
540AB
(b) FOR [121QM] (CHECK VALVE-FUEL DRAIN, R WING TK INR REAR)
640AB.
(5) Make sure that the applicable surge door 540BZ(640BZ) is open and that the 98D57004014000 HOOK-COVER (RIB2-SURGE DOORS) is installed.

Subtask 28-12-44-860-057-B ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration

Check Valve 50QM(51QM) 120QM(121QM) 93QM ** ON A/C NOT FOR ALL

Check Valve 50QM(51QM) 52QM(53QM) 120QM(121QM) 93QM ** ON A/C NOT FOR ALL

(1) Make sure that the applicable fuel tank is defueled (Ref. AMM TASK 28-25-00-650-001).
(2) Make sure that the remaining fuel has been drained from the applicable fuel tank (Ref. AMM TASK 28-25-00-650-003).
(3) Make sure that the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE is in position below the applicable access panel 540AB ( 640AB).
(4) Make sure that the applicable access panels are removed (Ref. AMM TASK 28-10-00-910-002):
(a) FOR [120QM] (CHECK VALVE-FUEL DRAIN, L WING TK INR REAR)
Remove 540AB (Ref. AMM TASK 57-27-11-000-001).
(b) FOR [121QM] (CHECK VALVE-FUEL DRAIN, R WING TK INR REAR)
Remove 640AB (Ref. AMM TASK 57-27-11-000-001).
(5) Make sure that the applicable RIB2 access panel 540BZ ( 640BZ) is removed (Ref. AMM TASK 57-27-12-000-002).

4. Procedure
Subtask 28-12-44-420-053-A

A. Installation of the Check Valve 120QM(121QM)

Check Valve 50QM(51QM) 52QM(53QM) 120QM(121QM) 93QM ** ON A/C NOT FOR ALL

Check Valve 50QM(51QM) 120QM(121QM) 93QM ** ON A/C NOT FOR ALL

(1) Hold the clamp (2) on the end of the pipe (1) and install the check-valve (3), with the flat face horizontal.
(2) Move the clamp (2) on to the check-valve (3) and tighten the clamp (2).

5. Close-up
Subtask 28-12-44-410-053-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the 98D57004014000 HOOK-COVER (RIB2-SURGE DOORS) and carefully close the surge door 540BZ(650BZ).
(3) Install the applicable access panel 540AB(640AB) (Ref. AMM TASK 57-27-11-400-001).

Subtask 28-12-44-410-053-B ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the applicable RIB2 access panel 540BZ ( 640BZ) (Ref. AMM TASK 57-27-12-400-002).
(3) Install the applicable access panels that follow:
(a) FOR [120QM] (CHECK VALVE-FUEL DRAIN, L WING TK INR REAR)
Install 540AB (Ref. AMM TASK 57-27-11-400-001).
(b) FOR [121QM] (CHECK VALVE-FUEL DRAIN, R WING TK INR REAR)
Install 640AB (Ref. AMM TASK 57-27-11-400-001).

Subtask 28-12-44-650-061-A

B. Fuel Configuration
(1) Refuel, defuel or transfer fuel as necessary (Ref. AMM TASK 12-11-28-650-003), (Ref. AMM TASK 28-25-00-650-001) or (Ref. AMM TASK 28-25-00-869-001).

Subtask 28-12-44-942-057-A

C. Removal of Equipment
(1) Remove the safety barriers.
(2) Remove the WARNING NOTICE(S).
(3) Remove the access platform(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 07:02:03 UTC