Operational Check of Air Inlet Check Valve 2150HM

TASK 21-26-56-280-002-A
Operational Check of Air Inlet Check Valve 2150HM

ZONE: 127
FIN: 2150HM

1. Reason for the Job
Refer to the MPD TASK: 212600-08
OPERATIONAL CHECK OF AIR INLET CHECK VALVE 2150 HM
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
127	REAR AVIONIC COMPARTMENT

C. Referenced Information

REFERENCE	DESIGNATION
TASK 21-26-56-000-001-A	Removal of the Air Inlet Check Valve
TASK 21-26-56-400-001-A	Installation of the Air Inlet Check Valve
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
Air Inlet Check Valve
Manual Opening and Closing of the Air Inlet Valve

3. Job Set-up

CAUTION: USE ONLY THE GROUND SERVICE NETWORK TO SUPPLY ELECTRICITY BECAUSE THE AVIONICS VENTILATION SYSTEM IS NOT SERVICEABLE. IF YOU ENERGIZE THE AIRCRAFT ELECTRICAL CIRCUITS WITHOUT THE VENTILATION SYSTEM YOU WILL CAUSE DAMAGE TO ELECTRICAL EQUIPMENT.

Subtask 21-26-56-861-053-A

A. Energize the ground service network (Ref. AMM TASK 24-42-00-861-001).

Subtask 21-26-56-865-055-A

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/AVNCS VENT/CTL	6HQ	D06
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05
122VU	AIR COND/AVNCS/VENT/MONG	3HQ	Y17
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AE02
** ON A/C ALL
123VU	AVNCS VENT/BLOWER/FAN	1HQ	AD10
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AC04

Subtask 21-26-56-010-053-A

C. Get Access
(1) Put an ACCESS PLATFORM 1M(3 FT) in position on the left side of the aircraft, below the skin air-inlet valve (15HQ).

4. Procedure
Subtask 21-26-56-010-055-B

A. Manual Opening of the Skin Air-Inlet Valve

CAUTION: DO NOT USE FORCE TO TURN THE HANDLE. THERE ARE SHEAR PINS IN THE HANDLE. IF YOU APPLY FORCE TO THE HANDLE WHEN THE FLAP IS IN THE FULLY OPEN OR CLOSED POSITION, THE SHEAR PINS WILL BREAK.

(1) If the skin air-inlet valve (15HQ) is closed, open it as follows:
(a) Push the PUSH latch to release the handle.
(b) Pull the handle to engage the mechanism.
(c) Set the deactivation switch to OFF.
(d) Turn the handle clockwise to fully open the flap.
(e) Stow and latch the handle.

Subtask 21-26-56-280-051-A

B. Manual Inspection of the Air-Inlet Check Valve
(1) Do a manual inspection of the air-inlet check valve (1) as follows:
(a) Through the inlet duct, make sure with your fingers that the air-inlet check valve (1) operates correctly and specially that:
1 The valve clappers touch their seats correctly.
2 The clappers move freely on their hinge pin.
3 The return springs operate correctly:
a Use your fingers to make sure that the clappers smoothly open and close around the hinge pin with the same return spring force.
(2) If the air-inlet check valve (1) does not operate correctly, replace it (Ref. AMM TASK 21-26-56-000-001) and (Ref. AMM TASK 21-26-56-400-001).

Subtask 21-26-56-410-054-B

C. Manual Closing of the Skin Air-Inlet Valve

WARNING: DO NOT USE YOUR FINGERS TO SET THE DEACTIVATION SWITCHES TO THE "ON" POSITION. USE A STICK, AND BE VERY CAREFUL. THE AVIONICS EQUIPMENT VENTILATION COMPUTER (AEVC) WILL POSSIBLY PUT VALVES 22HQ AND 15HQ DIRECTLY IN THE CLOSED POSITION AND THE FLAPS OF THE VALVES WILL CUT YOUR FINGERS.

CAUTION: DO NOT USE FORCE TO TURN THE HANDLE. THERE ARE SHEAR PINS IN THE HANDLE. IF YOU APPLY FORCE TO THE HANDLE WHEN THE FLAP IS IN THE FULLY OPEN OR CLOSED POSITION, THE SHEAR PINS WILL BREAK.

(1) If you opened the skin air-inlet valve (15HQ), close it as follows:
(a) Push the PUSH latch to release the handle.
(b) Pull the handle to engage the mechanism.
(c) Turn the handle counterclockwise to fully close the flap.
(d) Set the deactivation switch to ON.
(e) Stow and latch the handle.

5. Close-up
Subtask 21-26-56-410-052-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the access platform(s).

Subtask 21-26-56-865-056-A

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/AVNCS VENT/CTL	6HQ	D06
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05
122VU	AIR COND/AVNCS/VENT/MONG	3HQ	Y17
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AE02
** ON A/C ALL
123VU	AVNCS VENT/BLOWER/FAN	1HQ	AD10
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AC04

Subtask 21-26-56-862-053-A

C. De-energize the ground service network (Ref. AMM TASK 24-42-00-862-001).

[Rev.10 from 2021] 2026.04.02 06:11:10 UTC