Borescope Inspection of the Stage 1 Low-Pressure Turbine Nozzle Outer Air Duct Condition [CFMI]

TASK 72-53-00-290-802-A
Borescope Inspection of the Stage 1 Low-Pressure Turbine Nozzle Outer Air Duct Condition

1. Reason for the Job
Inspect the condition of the complete set of outer air ducts through the S17 or S18 borescope ports by using a flexible borescope, introduced in the cavity located between the Low Pressure Turbine (LPT) stage 1 outer platform and the High Pressure Turbine (HPT) shroud support.
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	BORESCOPE ACCESS BLANKING PLUG
No specific	1	BORESCOPE DIA 5.0 MM (7/32 IN) - FLEXIBLE
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 63 and 57 lbf.in (0.71 and 0.64 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP2101)	graphite grease
(Material No.CP2619)	Never Seez-Pure Nickel, Special
(Material No.CP8001)	lockwire 0.032 in. (0.8 mm) dia.
(Material No.CP8002)	lockwire 0.032 in. (0.8 mm) dia

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL, 452AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR, 461AL, 462AR

D. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-040-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-040-A	Closing of the Fan Cowl Doors
TASK 78-30-00-081-041-A	Make the Thrust Reverser Serviceable after Maintenance
TASK 78-30-00-481-041-A	Make the Thrust Reverser Unserviceable for Maintenance
TASK 78-36-00-010-040-A	Opening of the Thrust Reverser Doors
TASK 78-36-00-410-040-A	Closing of the Thrust Reverser Doors
Stage 1 LPT Nozzle and HPT Shroud Support
Stage 1 LPT Nozzle Outer Platform Cavity

3. Job Set-up
Subtask 72-53-00-941-055-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) in position to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than five minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize the FADEC 1(2).

Subtask 72-53-00-010-060-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put the ACCESS PLATFORM 1M(3 FT) in position.

Subtask 72-53-00-040-054-A ** ON A/C NOT FOR ALL

C. Make the thrust reverser unserviceable (Ref. AMM TASK 78-30-00-481-041).

Subtask 72-53-00-010-061-A ** ON A/C NOT FOR ALL

D. Open the thrust reverser doors (Ref. AMM TASK 78-36-00-010-040):
(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR

4. Procedure
Subtask 72-53-00-020-052-A ** ON A/C NOT FOR ALL

A. Remove the borescope plugs found immediately in front of the aft flange of the combustion case.

Subtask 72-53-00-290-054-A ** ON A/C NOT FOR ALL

B. Do a 360 degrees borescope inspection.

CAUTION: DO NOT USE A FLEXIBLE BORESCOPE WITH A DIAMETER LARGER THAN 0.19 IN. (5 MM). IF YOU DO NOT OBEY THIS INSTRUCTION, THERE IS A RISK THAT YOU CANNOT REMOVE IT FROM THE CAVITY.

(1) Insert the BORESCOPE DIA 5.0 MM (7/32 IN) - FLEXIBLE through the S17 or S18 port. Introduce the BORESCOPE DIA 5.0 MM (7/32 IN) - FLEXIBLE into the cavity as shown in

Stage 1 LPT Nozzle and HPT Shroud Support ** ON A/C NOT FOR ALL

Stage 1 LPT Nozzle Outer Platform Cavity ** ON A/C NOT FOR ALL

and perform a 180 degrees borescope inspection alternatively by lower and upper side.
(2) Inspect the full set of stage 1 LPT nozzle outer air ducts and use the limits that follow:

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Stage 1 LPT nozzle outer air duct:
A.Outer air duct found blocked, dislodged, missing.	Any number but not more than 30 outer air ducts.	If more than 30 outer air ducts are impacted, contact CFM.

Subtask 72-53-00-080-054-A ** ON A/C NOT FOR ALL

C. When the inspection is complete, remove the BORESCOPE DIA 5.0 MM (7/32 IN) - FLEXIBLE.

Subtask 72-53-00-420-052-A ** ON A/C NOT FOR ALL

D. Install Parts Removed for Borescope Inspection
(1) Apply a small amount of graphite grease (Material No.CP2101) or CP2619Never Seez-Pure Nickel, Special to the borescope plug threads and pressure faces.
(2) Install the BORESCOPE ACCESS BLANKING PLUG and TORQUE to between 63 and 57 lbf.in (0.71 and 0.64 m.daN )

.
(3) Safety the plugs with lockwire.

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(a) Safety the plugs with CP8001lockwire 0.032 in. (0.8 mm) dia. or CP8002lockwire 0.032 in. (0.8 mm) dia.

5. Close-up
Subtask 72-53-00-410-060-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser doors (Ref. AMM TASK 78-36-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR

Subtask 72-53-00-440-054-A ** ON A/C NOT FOR ALL

B. Make the thrust reverser serviceable (Ref. AMM TASK 78-30-00-081-041).

Subtask 72-53-00-410-061-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 02:39:38 UTC