Detailed Visual Inspection (DVI) of the Anti-Ice Valve

TASK 30-21-51-220-801-A
Detailed Visual Inspection (DVI) of the Anti-Ice Valve

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: 410

1. Reason for the Job
Self explanatory
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
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
410	ENG 1 PYLON BOX AND FORWARD FAIRING
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 30-21-51-000-804-A	Removal of the AFT Air-Intake Anti-Ice Valve (PRSOV1)
TASK 30-21-51-000-805-A	Removal of the FWD Air-Intake Anti-Ice Valve (PRSOV2)
TASK 30-21-51-300-801-A	Repair of the Heat Shields on the Anti-Ice Valves (Pressure Regulating and Shut-Off Valve (PRSOV) 1(2))
TASK 30-21-51-400-804-A	Installation of the AFT Air-Intake Anti-Ice Valve (PRSOV1)
TASK 30-21-51-400-805-A	Installation of the FWD Air-Intake Anti-Ice Valve (PRSOV2)
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-803-A	Closing of the Fan Cowl Doors
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-809-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
TASK 78-36-00-410-806-A	Closing of the Thrust Reverser Cowl Doors
Heat Shield of the Anti-Ice Valves (Pressure Regulating and Shut-Off Valve (PRSOV) 1 and 2)

3. Job Set-up
Subtask 30-21-51-941-068-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch, and
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 30-21-51-865-094-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
122VU	ANTI ICE/ENG/1	1DN1	X10
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
122VU	ANTI ICE/ENG/2	1DN2	W10

Subtask 30-21-51-010-093-A

C. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR

Subtask 30-21-51-040-063-A

D. Deactivation of the Thrust Reverser System for Ground Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for ground maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 30-21-51-010-094-A

E. Open the left thrust reverser cowl-door (Ref. AMM TASK 78-36-00-010-806):
(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL
(3) Put an ACCESS PLATFORM 1M(3 FT) in position.

4. Procedure
Subtask 30-21-51-220-050-A

A. Detailed Visual Inspection (DVI) of the Anti-Ice Valve Heat Shields
(1) Examine the heat shields of the anti-ice valves for:
(a) Cracks:
1 Maximum serviceable limit:
a Any number, 25.4 mm (1.00 in.) in length.
2 Maximum fly-on limit:
a For any number of cracks, more than 25.4 mm (1.00 in.) in length, you can continue in operation for a maximum of 100 flight cycles. After 100 flight cycles, you must repair the heat shield (Ref. AMM TASK 30-21-51-300-801) or replace the anti-ice valve:

For Pressure Regulating and Shut-Off Valve (PRSOV) 1: (Ref. AMM TASK 30-21-51-000-804) and (Ref. AMM TASK 30-21-51-400-804)
For PRSOV2: (Ref. AMM TASK 30-21-51-000-805) and (Ref. AMM TASK 30-21-51-400-805).

3 Maximum repairable limit:
a For any number of cracks, you can do the temporary repair (Ref. AMM TASK 30-21-51-300-801). After you do the temporary repair, you must do this DVI of the repaired heat shield each 50 flight cycles (maximum). After you do the temporary repair, you can continue in operation for a maximum of 500 flight cycles. After a maximum of 500 flight cycles, you must do the temporary repair a second time (Ref. AMM TASK 30-21-51-300-801), or replace the anti-ice valve:

For PRSOV1: (Ref. AMM TASK 30-21-51-000-804) and (Ref. AMM TASK 30-21-51-400-804)
For PRSOV2: (Ref. AMM TASK 30-21-51-000-805) and (Ref. AMM TASK 30-21-51-400-805).
You can do the temporary repair a maximum of two times before you must replace the anti-ice valve.

NOTE: You can contact Safran Nacelles for a possible extension of the 500-cycle life limit applicable to this repair procedure. Send a complete damage report that includes photographs when you ask for a possible extension of the 500-cycle life limit.

5. Close-up
Subtask 30-21-51-410-081-A

A. Close Access
(1) Remove the access platform(s).
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close the left thrust reverser cowl-door (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL

Subtask 30-21-51-440-059-A

B. Do the reactivation of the thrust reverser system after ground maintenance (Ref. AMM TASK 78-30-00-440-809).

Subtask 30-21-51-410-082-A

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Remove the WARNING NOTICE(S).

Subtask 30-21-51-865-095-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
122VU	ANTI ICE/ENG/1	1DN1	X10
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
122VU	ANTI ICE/ENG/2	1DN2	W10

[Rev.10 from 2021] 2026.04.01 00:30:37 UTC