Nacelle Anti-Icing (NAI) Valve Lock Open (Menu Mode) [CFML]

TASK 73-29-00-710-808-A
Nacelle Anti-Icing (NAI) Valve Lock Open (Menu Mode)

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

ZONE: 400

1. Reason for the Job
The NAI valve lock open function provides the ability to:

Lock the NAI valves in open position, in case of NAI valve Failed Closed failure for dispatch purposes.
Unlock the NAI valves from their open position. This option is used after a corrective maintenance action performed on the NAI valve following the failed closed detection.

This function has also a protection to prevent both NAI valves from being locked in open position at the same time through NAI lock open menu (and losing the NAI function that could lead to an overpressure at inlet level).
If the Menu Mode is entered on channel A, only the ability to lock the upstream NAI valve (PRSOV1) is displayed. If Menu Mode is entered on channel B, only the ability to lock the downstream NAI valve (PRSOV2) is displayed.
An ”Alternative Operational Test for the Trouble Shooting NAI Valves” should be performed after the NAI LOCK OPEN menu. NAI LOCK OPEN menu mode permits to send the lock open and unlocked open command. The ”Alternative Operational Test for the Trouble Shooting NAI Valves” permits to move and lock/unlock the NAI valve consequently.
2. Job Set-up Information
A. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS

B. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 30-21-00-710-802-A	Alternative Operational Test for the Trouble Shooting NAI Valves
TASK 31-32-00-860-012-A	Procedure to Get Access to the SYSTEM REPORT/TEST/ENG Page
TASK 71-00-00-860-829-A	Engine Shutdown
Function Terminated
FADEC Test (Main Menu)
Special Functions Menu Screen Format
NAIV LOCK OPEN Status Screen Format
NAIV LOCK OPEN Lock/Unlk Screen
NAIV LOCK SUCCESSFUL Screen
NAIV LOCK UNSUCCESSFUL Screen
NAIV UNLOCK SUCCESSFUL Screen
NAIV UNLOCK UNSUCCESSFUL Screen

3. Job Set-up
Subtask 73-29-00-861-079-A

A. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 73-29-00-865-092-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
49VU	ENGINE/1/FADEC A/AND EIU 1	2KS1	A04
121VU	ENGINE/ENG2/FADEC B/AND EIU2	4KS2	R41
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
49VU	ENGINE/2/FADEC A/AND EIU 2	2KS2	A05
121VU	ENGINE/ENG2/FADEC B/AND EIU2	4KS2	R41

Subtask 73-29-00-860-115-A

C. Aircraft Maintenance Configuration
(1) On ENG panel 115VU:
(a) Make sure that the ENG MASTER switch 1(2) is set to OFF.
(b) Make sure that the ENG/MODE rotary selector-switch is set to NORM.
(2) On the ENG section of maintenance panel 50VU:
(a) Release the FADEC GND PWR1(2) pushbutton switch. The ON legend of this pushbutton switch comes on.
1 After the FADEC is energized, wait ten seconds before you start the test. If you do not wait ten seconds, the interactive mode stops the EEC self-test and this can cause unwanted faults.
(3) On the left or right MCDU, get the SYSTEM REPORT/TEST/ENG page (Ref. AMM TASK 31-32-00-860-012).

NOTE: The EEC will not enter the menu mode (interactive mode) after an enquire command from the Centralized Fault Display System (CFDS) when any of the following conditions are set:

N2 more than ten percent or invalid
Engine not off
Engine not in default start state
Throttle Lever Angle (TLA) not at idle or invalid
Aircraft in the air
MASTER lever ON or invalid
BITE command code input label invalid.

NOTE: If one of the following conditions occurs while the NAI LOCK OPEN function is active, the function is aborted and the FUNCTION TERMINATED screen is displayed:

N2 more than 10 percent or invalid
Engine not in default start state
TLA not at idle or invalid
MASTER lever ON or invalid
You enter in the interactive mode of the other channel.
The test will need to be started again.

Function Terminated

NOTE: If one of the following conditions occurs while menu mode is active, the Menu Mode session will be exited directly, without displaying a specific screen:

RETURN key selected on main menu screen
Channel in Menu Mode is not the active channel
Invalid BITE command or Invalid equipment code received by EEC
A LOGOFF condition received by EEC
Engine start detected whereas function requiring idle speed (as Idle Test, Vibration Ground Run) is not active
Selected Mach more than 0.12 or invalid
Aircraft indicates in air.

4. Procedure
Subtask 73-29-00-710-086-A

A. Do the deactivation of the NAI valve
(1) Do the NAI Valve Lock Open (Menu Mode).

ACTION	RESULT
1.Initialize Menu Mode on the applicable engine and EEC, by selecting FADEC XY (x=Eng position, Y=channel number). If the Menu Mode is entered on channel A, there is only the ability to lock the upstream NAI valve (PRSOV1). If Menu Mode is entered on channel B, there is only the ability to lock the downstream NAI valve (PRSOV2).
2.From the Menu Mode main menu, push the key adjacent to SPECIAL FUNCTIONS (2R). FADEC Test (Main Menu)	The SPECIAL FUNCTIONS menu is shown. Special Functions Menu Screen Format
3.From the SPECIAL FUNCTIONS page, select the key adjacent to NAI LOCK OPEN (3R). Special Functions Menu Screen Format	The NAIV LOCK OPEN status screen is displayed. NAIV LOCK OPEN Status Screen Format
4.From the NAIV LOCK OPEN page, push the key adjacent to CONTINUE (5R). NOTE: This screen provides the NAI valve status.	The NAIV LOCK OPEN Lock/Unlock screen is displayed. NAIV LOCK OPEN Lock/Unlk Screen
5.From the NAIV LOCK OPEN Lock/Unlock: NAIV LOCK OPEN Lock/Unlk Screen
A.Lock NAI valve Open: Push the key adjacent to NAIV LOCK OPEN (2L).
When the other NAI valve is not locked out and the NVM store indication is successful.	NAIV LOCK SUCCESSFUL Screen is display. NAIV LOCK SUCCESSFUL Screen
When the other NAI valve is not locked out and the NVM store indication is unsuccessfull.	NAIV LOCK UNSUCCESSFUL Screen is display. NAIV LOCK UNSUCCESSFUL Screen
When the other NAI valve is locked out.	NAIV LOCK UNSUCCESSFUL Screen is display. NAIV LOCK UNSUCCESSFUL Screen NOTE: This is a protection to avoid having both NAI valves locked in the open position.
NOTE: If NAIV LOCK SUCCESSFUL Screen is displayed: Select the return key to come back to the Special Functions screen. Select the Return key to come back to the main menu.

(2) Perform an ”Alternative Operational Test for the Trouble Shooting NAI Valves” to move the NAI valve, on the channel where NAI valve has been locked to open position (Ref. AMM TASK 30-21-00-710-802). An ”Alternative Operational Test for the Trouble Shooting NAI Valves” shall be performed after the NAI LOCK OPEN menu. NAI LOCK OPEN menu mode permits to send the lock open and unlocked open command. The ”Alternative Operational Test for the Trouble Shooting NAI Valves” permits to move and lock/unlock the NAI valve consequently.
(3) As the NAI valve has been locked OPEN, EEC will detect a failure. Verify that the following NAI valve failed open message is displayed on the Post Flight Report (PFR):
ENGXY-2450-UP NAI VLV PRSOV1 (OPEN)
or ENGXY-2452-DOWN NAI VLV PRSOV2 (OPEN).
(4) Make sure that the fault message(s) related to the valve locked in the closed position or to both valves in the open position, is (are) not shown:
ENGXY-2464-UP NAI VLV PRSOV1 (CLOSED),
ENGXY-2465-DOWN NAI VLV PRSOV2 (CLOSED),
ENGXY-2462-NAI SYSTEM (OPEN).

Subtask 73-29-00-710-098-A

B. Do the reactivation of the NAI valve
(1) Do the NAI Valve Lock Open (Menu Mode).

ACTION	RESULT
1.Initialize Menu Mode on the applicable engine and EEC, by selecting FADEC XY (x=Eng position, Y=channel number). If the Menu Mode is entered on channel A, there is only the ability to lock the upstream NAI valve (PRSOV1). If Menu Mode is entered on channel B, there is only the ability to lock the downstream NAI valve (PRSOV2).
2.From the Menu Mode main menu, push the key adjacent to SPECIAL FUNCTIONS (2R). FADEC Test (Main Menu)	The SPECIAL FUNCTIONS menu is shown. Special Functions Menu Screen Format
3.From the SPECIAL FUNCTIONS page, select the key adjacent to NAI LOCK OPEN (3R). Special Functions Menu Screen Format	The NAIV LOCK OPEN status screen is displayed. NAIV LOCK OPEN Status Screen Format
4.From the NAIV LOCK OPEN page, push the key adjacent to CONTINUE (5R). NOTE: This screen provides the NAI valve status.	The NAIV LOCK OPEN Lock/Unlock screen is displayed. NAIV LOCK OPEN Lock/Unlk Screen
5.From the NAIV LOCK OPEN Lock/Unlock: NAIV LOCK OPEN Lock/Unlk Screen
A.Unlock NAI valve: Push the key adjacent to NAIV LOCK OPEN (3L). NOTE: If the Menu Mode is entered on channel A, there is only the ability to lock the NAI valve (PRSOV1). If Menu Mode is entered on channel B, there is only the ability to lock the downstream NAI valve (PRSOV2).
When the NVM store indication is successful.	NAIV UNLOCK SUCCESSFUL Screen is display. NAIV UNLOCK SUCCESSFUL Screen
When the NVM store indication is unsuccessful.	NAIV UNLOCK UNSUCCESSFUL Screen is display. NAIV UNLOCK UNSUCCESSFUL Screen
6.Press key adjacent to RETURN (6L) to return to the SPECIAL FUNCTIONS menu.	The SPECIAL FUNCTIONS menu is shown. Special Functions Menu Screen Format
7.If NAIV UNLOCK SUCCESSFUL Screen is displayed: Select the return key to come back to the Special Functions screen. Select the return key to come back to the main menu.

(2) Perform an ”Alternative Operational Test for the Trouble Shooting NAI Valves” to move the NAI valve, on the channel where NAI valve has been unlocked from its open position (Ref. AMM TASK 30-21-00-710-802).
(3) Verify that the following NAI valve messages are NOT displayed on the PFR:
ENGXY-2450-UP NAI VLV PRSOV1 (OPEN) or
ENGXY-2452-DOWN NAI VLV PRSOV2 (OPEN) or
ENGXY-2464-UP NAI VLV PRSOV1 (CLOSED) or
ENGXY-2465-DOWN NAI VLV PRSOV2 (CLOSED) or
ENGXY-2462-NAI SYSTEM (OPEN).

5. Close-up
Subtask 73-29-00-860-116-A

A. Put the aircraft back to its initial configuration.
(1) When the Alternative Operational Test for the Trouble Shooting NAI Valves is complete, stop the engine (Ref. AMM TASK 71-00-00-860-829).
(2) Make sure that the ENG/MODE/ CRANK/NORM/IGN/START selector switch is in the NORM position.
(3) Put the Master lever switch to the OFF position.
(4) On the ENG section of maintenance panel 50VU:
(a) Release the FADEC GND PWR 1(2) pushbutton switch (the ON legend goes off).
(5) On the overhead panel, on the ADIRS CDU, set the three OFF/NAV/ATT selector switches to OFF.
(6) Remove the WARNING NOTICE(S).
(7) If relevant, put a WARNING NOTICE(S) in position in the cockpit to tell persons that the NAI valve 1(2) is deactivated in the open position.
(8) Make an entry in the logbook.

Subtask 73-29-00-862-079-A

B. De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 03:06:19 UTC