Removal of the Check Valve
TASK 28-12-44-000-003-A
Removal of the Check Valve
Self Explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 28-12-44-941-063-A
Subtask 28-12-44-020-052-A
[Rev.10 from 2021]
2026.04.02 06:17:11 UTC
Removal of the Check Valve
WARNING:
PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:
- THE FLIGHT CONTROLS
- THE FLIGHT CONTROL SURFACES
- THE LANDING GEAR AND THE RELATED DOORS
- COMPONENTS THAT MOVE.
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.
1. Reason for the JobSelf 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) |
| 98D57004014000 | 1 | HOOK-COVER (RIB2-SURGE DOORS) |
| 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 | |
| REFERENCE | DESIGNATION |
|---|---|
| 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 57-27-11-000-001-A | Removal of the Access Panel |
| TASK 57-27-12-000-002-A | Removal of the Rib 2 Access Panel 540AZ(640AZ) or 540BZ(640BZ) |
| FOR [120QM] (CHECK VALVE-FUEL DRAIN, L WING TK INR REAR) | |
| TASK 28-10-00-910-002-A | Access to the Fuel Tanks and the Work Areas |
| TASK 57-27-11-000-001-A | Removal of the Access Panel |
| FOR [121QM] (CHECK VALVE-FUEL DRAIN, R WING TK INR REAR) | |
| TASK 28-10-00-910-002-A | Access to the Fuel Tanks and the Work Areas |
| TASK 57-27-11-000-001-A | Removal of the Access Panel |
Subtask 28-12-44-941-063-A
A. Safety Precautions
(2) Put the SAFETY BARRIER(S) in position.
Subtask 28-12-44-860-055-A 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) Put the SAFETY BARRIER(S) in position.
B. Aircraft Maintenance Configuration
(1) Defuel the applicable fuel tank (Ref. AMM TASK 28-25-00-650-001).
(2) Drain the remaining fuel from the applicable fuel tank (Ref. AMM TASK 28-25-00-650-003).
Subtask 28-12-44-010-052-A ** ON A/C NOT FOR ALL (1) Defuel the applicable fuel tank (Ref. AMM TASK 28-25-00-650-001).
(2) Drain the remaining fuel from the applicable fuel tank (Ref. AMM TASK 28-25-00-650-003).
C. Get Access
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) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE below the applicable access door 540AB(640AB).
(2) Remove the applicable access panel 540AB(640AB) (Ref. AMM TASK 28-10-00-910-002), (Ref. AMM TASK 57-27-11-000-001).
(3) Open the aft surge door 540BZ(640BZ).
(4) Install the 98D57004014000 HOOK-COVER (RIB2-SURGE DOORS) to hold the surge door open.
Subtask 28-12-44-010-052-B ** ON A/C NOT FOR ALL
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 (2) Remove the applicable access panel 540AB(640AB) (Ref. AMM TASK 28-10-00-910-002), (Ref. AMM TASK 57-27-11-000-001).
(3) Open the aft surge door 540BZ(640BZ).
(4) Install the 98D57004014000 HOOK-COVER (RIB2-SURGE DOORS) to hold the surge door open.
C. Get Access
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) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE below the applicable access panel 540AB ( 640AB).
(2) Remove the applicable access panels that follow:
(a) FOR [120QM] (CHECK VALVE-FUEL DRAIN, L WING TK INR REAR)
Remove 540AB (Ref. AMM TASK 28-10-00-910-002) and (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 28-10-00-910-002) and (Ref. AMM TASK 57-27-11-000-001).
(3) Remove the applicable RIB2 access panel 540BZ ( 640BZ) (Ref. AMM TASK 57-27-12-000-002).
4. Procedure
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 (2) Remove the applicable access panels that follow:
(a) FOR [120QM] (CHECK VALVE-FUEL DRAIN, L WING TK INR REAR)
Remove 540AB (Ref. AMM TASK 28-10-00-910-002) and (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 28-10-00-910-002) and (Ref. AMM TASK 57-27-11-000-001).
(3) Remove the applicable RIB2 access panel 540BZ ( 640BZ) (Ref. AMM TASK 57-27-12-000-002).
Subtask 28-12-44-020-052-A
A. Removal 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) Loosen the clamp (2) and move it along the pipe (1) away from the check-valve (3).
(2) Remove the check-valve (3) from the pipe (1) and remove the clamp (2).
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 (2) Remove the check-valve (3) from the pipe (1) and remove the clamp (2).