Removal of the Clack Valve (RIB2)

TASK 28-11-42-000-001-A
Removal of the Clack Valve (RIB2)

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.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

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 2M (6 FT)
No specific	1	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	AR	SAFETY BARRIER(S)
98D57004013000	1	HOOK-COVER (RIB 2 SURGE DOORS)
98D57004014000	1	HOOK-COVER (RIB2-SURGE DOORS)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
540AB, 540AZ, 540BZ, 640AB, 640AZ, 640BZ

C. Referenced Information

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)
Clack valve ** ON A/C NOT FOR ALL
Clack Valve ** ON A/C NOT FOR ALL
Clack Valve ** ON A/C NOT FOR ALL
Clack Valve ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-11-42-941-050-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) Put the SAFETY BARRIER(S) in position.

Subtask 28-11-42-650-052-A

B. Fuel 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 28-11-42-010-050-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) in position.
(2) Remove the applicable access panel 540AB 640AB, (Ref. AMM TASK 57-27-11-000-001) and (Ref. AMM TASK 28-10-00-910-002).
(3) Open the applicable hinged access door to get access to the clack valve (9):

hold open the forward access door 540AZ 640AZ with the 98D57004013000 HOOK-COVER (RIB 2 SURGE DOORS)
hold open the applicable aft surge door 540BZ 640BZ with the 98D57004014000 HOOK-COVER (RIB2-SURGE DOORS).

Subtask 28-11-42-010-050-B ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position below access panel 540AB ( 640AB).
(2) Remove the applicable access panel 540AB ( 640AB) (Ref. AMM TASK 57-27-11-000-001) and (Ref. AMM TASK 28-10-00-910-002).
(3) Remove the applicable RIB2 access panels to get access to the applicable clack valves:

For the left wing, remove 540AZ and 540BZ (Ref. AMM TASK 57-27-12-000-002)
For the right wing, remove 640AZ and 640BZ (Ref. AMM TASK 57-27-12-000-002).

4. Procedure

NOTE: Make sure that you keep the applicable clack valve and seating together. Make a record of the position of the applicable clack valves and seatings as they are not interchangeable.

Subtask 28-11-42-020-050-A ** ON A/C NOT FOR ALL

A. Removal ot the Clack Valve (RIB 2)
(1) To remove the clack valve (9) from the seating (4) or (14):
(a) Remove one of the cotter pins (3) and one of the collars (2) from the spindle (8). Discard the cotter pin, that you removed.
(b) Remove the spindle (8), the distance-tubes (1) and the clack valve (9), from the seating (4) or (14).
(2) To remove the seating (4) or (14) from the rib:
(a) Engage a hexagon key in the recess of each screw (10), (11) or (12) to prevent movement of the screw.
(b) Remove the nuts (7), the washers (6) and the screws (10), (11) or (12), then remove the seating (4) or (14) from the rib.
(c) Remove and discard the O-ring (5) or (13).

Subtask 28-11-42-020-050-B ** ON A/C NOT FOR ALL

A. Removal of the Clack Valve (RIB 2)
(1) To remove the clack valve (9) from the seating (4) or (13):
(a) Remove one of the cotter pins (3) and one of the collars (2) from the spindle (8). Discard the cotter pin, that you removed.
(b) Remove the spindle (8), the distance-tubes (1) and the clack valve (9), from the seating (4) or (13).
(2) To remove the seating (4) or (13) from the rib:
(a) Engage a hexagon key in the recess of each screw (10) or (11) to prevent movement of the screw.
(b) Remove the nuts (7), the washers (6) and the screws (10) or (11), then remove the seating (4) or (13) from the rib.
(c) Remove and discard the O-ring (5) or (12).

Subtask 28-11-42-020-050-C ** ON A/C NOT FOR ALL

A. Removal of the Clack Valve (RIB2)
(1) To remove the clack valve (9) or (14) from the seating (3) or (11), do the steps that follow:
(a) Remove one of the cotter pins (1).
(b) Remove one of the collars (2) from the spindle (8).
(c) Discard the cotter pin that you removed from the seating (3) or (11).
(d) Remove the spindle (8) and the distance-tubes (10).
(e) Remove the clack valve (9) or (13) from the seating (3) or (11).
(2) To remove the seating (11) from RIB2, do the steps that follow:
(a) Engage a hexagon key in the recess of each screw (5) and (13) to prevent the movement of the screw.
(b) Remove the nuts (7), the washers (6) and the screws (5) and (13).
(c) Remove the seating (11) from RIB2.
(d) Remove and discard the O-ring (12).
(3) To remove the seating (3) from RIB2, do the steps that follow:
(a) Engage a hexagon key in the recess of each screw (5) to prevent the movement of the screw.
(b) Remove the nuts (7), the washers (6) and the screws (5).
(c) Remove the seating (3) from RIB2.
(d) Remove and discard the O-ring (4).

Subtask 28-11-42-020-050-D ** ON A/C NOT FOR ALL

A. Removal of the Clack Valve (RIB2)
(1) To remove the clack valve (9) or (13) from the seating (3) or (11), do the steps that follow:
(a) Remove one of the cotter pins (1).
(b) Remove one of the collars (2) from the spindle (8).
(c) Discard the cotter pin that you removed from the seating (3) or (11).
(d) Remove the spindle (8) and the distance-tubes (10).
(e) Remove the clack valve (9) or (13) from the seating (3) or (11).
(2) To remove the seating (11) from RIB2, do the steps that follow:
(a) Engage a hexagon key in the recess of each screw (5) to prevent the movement of the screw.
(b) Remove the nuts (7), the washers (6) and the screws (5).
(c) Remove the seating (11) from RIB2.
(d) Remove and discard the O-ring (12).
(3) To remove the seating (3) from RIB2, do the steps that follow:
(a) Engage a hexagon key in the recess of each screw (5) and (14) to prevent the movement of the screw.
(b) Remove the nuts (7), the washers (6) and the screws (5) and (14).
(c) Remove the seating (3) from RIB2.
(d) Remove and discard the O-ring (4).

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