Borescope Inspection of the High Pressure Compressor Section [CFML]

TASK 72-30-00-290-801-A
Borescope Inspection of the High Pressure Compressor Section

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.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 400

1. Reason for the Job
This procedure gives criteria for the borescope inspection of the High Pressure Compressor Section.

NOTE: You can use equivalent alternatives for standard tools, equipment and consumable materials.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 20 and 15 lbf.in (0.23 and 0.17 m.daN )
No specific	Torque wrench: range to between 86 and 74 lbf.in (0.97 and 0.84 m.daN )
No specific	Torque wrench: range to between 189 and 161 lbf.in (2.14 and 1.82 m.daN )
No specific	Torque wrench: range to between 221 and 189 lbf.in (2.50 and 2.14 m.daN )
856A1320	1	BORESCOPE-KIT
856A1321	1	FIBERSCOPE SET
856A1322	1	BORESCOPE-LIGHT SOURCE SET

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP2442)	engine oil
(Material No.CP2619)	Never Seez-Pure Nickel, Special
(Material No.CP8002)	safetywire
(Material No.CP8006)	safety cable 0.032 in. (0.8 mm) US SPEC M50 TF 9 C1-A

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL, 462AR

D. Referenced Information

REFERENCE	DESIGNATION
TASK 36-11-00-210-805-A	Visual Inspection of the Engine Bleed Air System (EBAS) after the Damage of the Engine Compressor
TASK 70-24-00-910-815-A	Locking Procedures
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 72-00-00-290-812-A	Engine Borescope Examination Preparation
TASK 72-00-00-820-802-A	Find the Zero Index Mark of the High Pressure Compressor (HPC) Rotor
TASK 72-00-00-820-803-A	Turning of the N2 Rotor
TASK 72-24-00-300-801-A	Borescope Plug D Removal and Installation Procedure
TASK 72-24-01-000-801-A	Removal of Segment Shrouds 1 thru 5
TASK 72-24-01-400-801-A	Installation of Segment Shrouds 1 thru 5
TASK 72-31-05-300-801-A	Borescope Blending of the High Pressure Compressor (HPC) Blades
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
TASK 80-11-05-210-802-A	Visual Inspection of the Pneumatic Air Starter
TASK 80-12-49-000-802-A	Removal of the Starter Air Duct (from the Pylon to the Starter Air Valve (SAV))
TASK 80-12-49-400-802-A	Installation of the Starter Air Duct (from the Pylon to the Starter Air Valve (SAV))
High Pressure Compressor Section Inspection

3. Job Set-up
Subtask 72-30-00-941-051-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
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 72-30-00-010-053-A

B. 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 72-30-00-040-050-A

C. Deactivation of the Thrust Reverser System for 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 72-30-00-010-054-A

D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
(2) Put an ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position.

4. Procedure

CAUTION: MAKE SURE THE TEMPERATURE OF THE ENGINE AND OF THE AREAS ADJACENT TO THE BORESCOPE INSPECTION PORTS IS LESS THAN 150 °F (65.6 °C). DO NOT DO A BORESCOPE INSPECTION IF THE ADJACENT AREAS ARE TOO HOT TO TOUCH. DO THE BORESCOPE INSPECTION WHEN THE ENGINE TEMPERATURE IS LESS THAN 150 F(65.6 C). THIS WILL PREVENT DAMAGE TO THE BORESCOPE EQUIPMENT.

Subtask 72-30-00-290-050-A

A. Do the Borescope Examination Preparation
(1) Do the borescope examination preparation (Ref. AMM TASK 72-00-00-290-812).

Subtask 72-30-00-820-050-A

B. Find the Zero Index Mark of the N2 Rotor
(1) Find the zero index mark of the N2 rotor (Ref. AMM TASK 72-00-00-820-802).

Subtask 72-30-00-010-055-A

C. Removal of the Segment Shroud 3.
(1) Remove the segment shroud 3. (Ref. AMM TASK 72-24-01-000-801).

NOTE: It is not necessary to remove shroud segment 2 at this time unless there is damage to the Stage 1 airfoil(s) which can be boroblended.

Subtask 72-30-00-020-053-A

D. Do Further Preparation as Follows:

WARNING: USE GOGGLES WHEN YOU REMOVE OR INSTALL SAFETY CABLE. EACH TIME YOU CUT SAFETY CABLE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE SAFETY CABLE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

(1) Remove the borescope plugs from ports C, E thru M (Ref. AMM TASK 72-00-00-290-812).

NOTE: To remove borescope plug from port H, cut off CP8006safety cable 0.032 in. (0.8 mm) US SPEC M50 TF 9 C1-A or safetywire (Material No.CP8002) .

NOTE: It is not necessary to remove borescope plug D at this time unless damage found on the Stage 1 Blisk Airfoils. Instructions for plug D removal (Ref. AMM TASK 72-24-00-300-801).

NOTE: Borescope plug M is installed only on PRE-SB 72-0219 engines.

(a) Put an identification tag on each borescope plug.
(2) Turn ON the 856A1322 BORESCOPE-LIGHT SOURCE SET and insert the rigid 856A1320 BORESCOPE-KIT or 856A1321 FIBERSCOPE SET into its position for the inspection.

NOTE: This inspection is limited to what you can see with the rigid borescope.

(3) Manually or electrically turn the HPC rotor (Ref. AMM TASK 72-00-00-820-803).

Subtask 72-30-00-290-051-A

E. High Pressure Compressor Section Inspection
(1) The HPC airfoil/blade count by stage is given in table 1:
Table 1

STAGE NUMBER	NUMBER OF AIRFOILS/BLADES	NOTES
1	25	Stage 1 of the HPC is a blisk
2	34	Stage 2 of the HPC is a blisk
3	39	Stage 3 of the HPC is a blisk
4	49	Stage 4 of the HPC is a blisk
5	56	Stage 5 of the HPC is a blisk
6	66
7	61
8	67
9	64
10	68

(2) Do an inspection of:

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Examine the HPC stage 1 blisk airfoil as follows: High Pressure Compressor Section Inspection
A.Particles on the airfoil surface.	There is no limit to the amount of particle buildup permitted.
B.Cracks and tears.	No cracks or tears are permitted.	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits. Blending is applicable to tears (not cracks) in the airfoil Leading Edges (LE) or Trailing Edges (TE). See task for complete details.
C.Scratches in all areas of the airfoil or flowpath. See detail A.	There is no limit to the number of scratches that are less than 0.002 in. (0.05 mm) in depth.
D.Nicks and dents on the center of airfoil. See detail G area E.	There is no limit to the number of nicks and dents, with these conditions: The nick or dent is more than 0.100 in. (2.54 mm) from the LE and TE The nick or dent does not make a hole in the airfoil The nick or dent is less than 0.020 in. (0.51 mm) in diameter The nick or dent is less than 0.003 in. (0.08 mm) in depth.
E.Nicks and dents in the airfoil root radius. See details G, H area A.	There is no limit to the number of nicks and dents that are less than 0.002 in. (0.05 mm) in depth.
F.Nicks, dents and missing material in the lower span from the top of the root radius to 40 percent of TH or TL at the LE or TE of the airfoil respectively. See detail G area B.	There is no limit to the number of nicks, dents and missing material up to 0.017 in. (0.43 mm) in depth.	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend in limits.
G.Nicks, dents and missing material in the upper span from 40 percent of TH or TL up to and including the tip corner region at the LE or TE respectively. See detail G areas C and D.	There is no limit to the number of nicks, dents and missing material up to 0.020 in. (0.51 mm) in depth.	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits.
H.Distortion or bulging of the LE. See detail C.	It is permitted to have distortion or bulging in the LE up to three airfoils per stage with these conditions: The distortion or bulge is in the top 50 percent of the airfoil Depth does not exceed 30 percent of chord DIM A. See detail E Deflection T damage up to 0.042 in. (1.07 mm) maximum The length D damage must be more than three times the deflection T damage There is no more than one area of distortion or bulging in each airfoil.	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits.
J.Airfoil tip corners that are missing. See detail G area D.	The maximum allowable limit is 0.085 in. (2.16 mm) chord-wise and 0.085 in. (2.16 mm) span-wise from the tip of the airfoil at the LE and TE. Maximum allowable number of airfoils affected = 6.	Some airfoil tip corners can be chamfered at the LE, TE or both. The chamfers are smooth angular cuts and are used to identify blades with tip notches. This condition is fully serviceable and is not the same as missing corners. See detail D.
K.Airfoil tip curls. See detail F.	There is no limit on the number of curled stage 1 blisk airfoil tips, if the total blockage area is not greater than 0.544 in.2 (350.97 mm2) and there are no tears or cracks as a result of the tip curl.	Measure the forward tip corner and axial displacements and the maximum deflection from the initial contour of a tip curl on the forward tip corner of the stage 1 HPC airfoils. See the detail F: Measure and record the radial displacement (DIM. L) down the LE Measure and record the axial displacement (DIM. Y) along the blade tip chord Measure and record the maximum deflection (Angle A) from the initial contour Find the total blockage area corrective factor as follows: If the maximum deflection (Angle A) from an initial contour is not more than 25 degrees, the corrective Factor (CF) to be used is 0.22 If the maximum deflection (Angle A) from an initial contour is more than 25 degrees and not more than 45 degrees the corrective factor (CF) to be used is 0.36 If the maximum deflection angle is more than 45 degrees, the corrective factor (CF) to be used is 0.50 Calculate the blockage area (BA) as follows: Multiply the radial displacement (L) by the axial displacement (Y) and by the appropriate corrective factor (CF). (For example, BA = DIM. L x DIM Y x CF) If more than one tip curl is found, sum the blockage area (BA) corresponding to each tip curl and then consider the Total Blockage Area (TBA). (For example, TBA = BA1 + BA2 + BA3).
L.Burrs and high metal on the airfoil tip due to rub.	Any amount is permitted.
2.Examine the HPC stage 2-5 blisk airfoils as follows:
A.Particles on the airfoil surface.	There is no limit to the amount of particle buildup permitted.
B.Cracks and tears.	No cracks or tears are permitted.	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits. Blending is applicable to tears (not cracks) in the airfoil LE or TE. See task for complete details.
C.Scratches in all areas of the airfoil or flowpath. See detail A.	There is no limit to the number of scratches that are less than 0.002 in. (0.05 mm) in depth.
D.Nicks and dents in the center of airfoil. See detail G area E.	There is no limit to the number of nicks and dents, with these conditions: The nick or dent is more than 0.100 in. (2.54 mm) from the LE and the TE The nick or dent does not make a hole in the blade The nick or dent is less than 0.020 in. (0.51 mm) in diameter The nick or dent is less than 0.003 in. (0.08 mm) in depth.
E.Nicks and dents in the airfoil root radius. See details G, H area A.	There is no limit to the number of nicks and dents that are less than 0.002 in. (0.05 mm) in depth.	NOTE: The stage 3 blisk LE could have a machining feature near the root fillet from the new make process. These features must have a smooth transition between the fillet and LE. The maximum chordwise depth (DIM. Z) will be up to 0.0060 in. (0.1524 mm) The maximum spanwise extent (DIM. Q) is 0.2200 in. (5.59 mm) from the flowpath Measure DIM. Q and DIM. Z and calculate the ratio of these features (DIM. Q/DIM. Z). If the ratio result is more than 25, the feature must not be interpreted as nicks or dents caused by foreign object damage or existing boroblend. Refer to detail L.
F.Nicks, dents and missing material in the lower span from the top of the root radius to 40 percent of TH or TL at the LE or TE of the airfoil respectively. See detail G area B.	There is no limit to the number of nicks, dents and missing material up to: Stage 2: 0.022 in. (0.56 mm) Stage 3: 0.030 in. (0.76 mm) Stage 4: 0.030 in. (0.76 mm) Stage 5: 0.030 in. (0.76 mm).	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits.
G.Nicks, dents and missing material in the upper span from 40 percent of TH or TL up to and including the tip corner region, at the LE or TE respectively. See detail G, areas C and D.	There is no limit to the number of nicks, dents and missing material up to: Stage 2: 0.015 in. (0.38 mm) Stage 3: 0.025 in. (0.63 mm) Stage 4: 0.013 in. (0.33 mm) Stage 5: 0.030 in. (0.76 mm).	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits.
H.Distortion or bulging of the LE. See detail C.	It is permitted to have distortion or bulging in the LE up to three airfoils per stage with these conditions: The distortion or bulge is in the top 50 percent of the airfoil Depth does not exceed 30 percent of chord DIM. A (see detail E) Deflection T damage up to 0.042 in. (1.07 mm) maximum The length D damage must be more than three times the deflection T damage There is no more than one area of distortion or bulging in each airfoil.	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits.
J.Airfoil tip corners that are missing. See detail G area D.	Maximum allowable limit is 0.085 in. (2.16 mm) chord-wise and 0.085 in. (2.16 mm) span-wise from the tip of the airfoil at the LE and TE. Maximum allowable number of airfoils affected = 6.	Some airfoil tip corners can be chamfered at the LE, TE or both. The chamfers are smooth angular cuts and are used to identify blades with tip notches. This condition is fully serviceable and is not the same as missing corners. See detail D.
K.Airfoil tip curls. See detail F.	Airfoil tip curls are permitted with these conditions: The tip curl is less than 0.200 in. (5.08 mm) in length along the airfoil tip chord (DIM Y) There are no tears or cracks as a result of the tip curl The maximum number of airfoils permitted with tip curls: Stage 2: 3 airfoils Stage 3: 3 airfoils. NOTE: Stage 3 can have one single airfoil with a tip curl of up to 0.255 in. (6.48 mm) spanwise (DIM. L), by 0.800 in. (20.32 mm) chordwise (DIM. Y) only if there are no other stage 3 airfoils with any amount of tip curl. Stage 4: 4 airfoils Stage 5: 5 airfoils.
L.Burrs and high metal on the airfoil tip due to rub.	Any amount is permitted.
3.Examine the HPC stage 6-9 blades as follows:		If HPC stage 10 blades are inspected, all inspection criteria and limits (A-L) will apply. NOTE: When you do a borescope inspection, gaps between blade platforms can be visible. The gaps are normal and there is no limit to the gap size.
A.Particles on the airfoil surface.	There is no limit to the amount of particle buildup permitted.
B.Cracks and tears.	No cracks or tears are permitted.	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits. Blending is applicable to tears (not cracks) in the airfoil LE or TE. See task for complete details.
C.Scratches in all areas of the airfoil and platform of the blade. See detail B.	There is no limit to the number of scratches that are less than 0.003 in. (0.08 mm) in depth.
D.Nicks and dents on the center of the airfoil. See detail J area E.	There is no limit to the number of nicks and dents with these conditions: The nick or dent is more than 0.040 in. (1.02 mm) from the LE and TE The nick or dent does not make a hole in the airfoil The nick or dent that pushes metal through to the opposite side is permitted The nick or dent is less than 0.005 in. (0.13 mm) in depth.
E.Nicks and dents in the airfoil root radius. See details J, K area A.	There is no limit to the number of nicks and dents that are less than 0.003 in. (0.08 mm) in depth.
F.Nicks, dents and missing material in the lower span from the top of the root radius to 40 percent of TH or TL at the LE or TE of the airfoil respectively. See detail J area B.	There is no limit to the number of nicks, dents and missing material to up: Stage 6: 0.030 in. (0.76 mm) in depth Stage 7: 0.030 in. (0.76 mm) in depth Stage 8: 0.030 in. (0.76 mm) in depth Stage 9: 0.030 in. (0.76 mm) in depth Stage 10: 0.030 in. (0.76 mm) in depth.	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits.
G.Nicks, dents and missing material in the upper span from 40 percent of TH or TL up to and including the tip corner region at the LE or TE respectively. See detail J, areas C and D.	There is no limit to the number of nicks, dents and missing material up to: Stage 6: 0.030 in. (0.76 mm) in depth Stage 7: 0.035 in. (0.89 mm) in depth Stage 8: 0.025 in. (0.63 mm) in depth Stage 9: 0.025 in. (0.63 mm) in depth Stage 10: 0.035 in. (0.89 mm) in depth.	Refer to (Ref. AMM TASK 72-31-05-300-801) for airfoil blend limits.
H.Airfoil tip corners that are missing. See detail J, area D.	Maximum allowable limit is 0.085 in. (2.16 mm) chord-wise and 0.085 in. (2.16 mm) span-wise from the tip of the airfoil at the LE and TE. Maximum allowable number of blades affected = 6.	Some airfoil tip corners can be chamfered at the LE, TE or both. The chamfers are smooth angular cuts and are used to identify blades with tip notches. This condition is fully serviceable and is not the same as missing corners. See detail D.
J.Airfoil tip curls. See detail F.	A maximum of six blades on each stage can be affected by tip curls with these conditions: The tip curl is less than 0.136 in. (3.45 mm) in length (DIM.Y) along the airfoil tip chord There are no tears or cracks as a result of the tip curl.
K.Burrs and high metal on the blade tip due to rub.	Any amount is permitted.
L.Radial tip cracks.	No radial tip cracks are permitted.
M.Blade platforms shingling or overlapping.	Not permitted.
N.Stage 6-10 blade locking lugs.	One crack in the circumferential direction on one lock lug is permitted for each stage. There must be no effect on the other lock lug.	High Pressure Compressor Section Inspection

Subtask 72-30-00-080-050-A

F. When the inspection is completed, remove the 856A1320 BORESCOPE-KIT or the 856A1321 FIBERSCOPE SET.

Subtask 72-30-00-200-051-A

G. If generation of debris due to significant High Pressure Compressor damage
(1) Inspect the bleed air system components for foreign object damage, Repair or replace components if unserviceable damage is identified during inspection.

NOTE: Remove FOD if found during the inspection.

(a) Inspect the bleed air system component (Ref. AMM TASK 36-11-00-210-805)
(b) Inspect the starter air valve, starter and starter air duct:
1 Remove the starter air duct (Ref. AMM TASK 80-12-49-000-802)
2 Do a borescope inspection of the starter air duct for any signs of Foreign Object Damage (FOD).
3 Visually inspect the starter air valve air flow path and starter for any signs of Foreign Object Damage (FOD) (Ref. AMM TASK 80-11-05-210-802)
4 Install the starter air duct (Ref. AMM TASK 80-12-49-400-802)

Subtask 72-30-00-420-050-A

H. Install Borescope Plug C as Follows:
(1) Do a visual inspection of the borescope plug and the borescope port (Ref. AMM TASK 72-00-00-290-812).
(2) Remove the identification tag from borescope plug C before the installation of the plug.
(3) Put engine oil (Material No.CP2442) on the borescope plug threads and the mating surfaces.
(4) Install borescope plug C in the borescope port.
(a) TORQUE the borescope plug to between 189 and 161 lbf.in (2.14 and 1.82 m.daN )

.
(5) Install borescope plug D (Ref. AMM TASK 72-24-00-300-801).

Subtask 72-30-00-420-051-A

I. Install borescope plugs E, F, G, H and K as follows:
(1) Do a visual inspection of the borescope plugs and the borescope ports (Ref. AMM TASK 72-00-00-290-812).
(2) Remove the identification tag from borescope plugs E, F, G, H and K before the installation of the plug.
(3) Put CP2619Never Seez-Pure Nickel, Special on the borescope plug threads.

NOTE: Do not apply anti-seize on the mating surfaces.

(4) Install borescope plugs E, F, G, H and K in the borescope ports as follows:
(a) TORQUE the borescope plugs to between 221 and 189 lbf.in (2.50 and 2.14 m.daN )

.
(b) Break the torque, one plug at a time.
(c) Loosen the plug by rotating a minimum of 180 degrees after the torque is broken.
(d) TORQUE the loosened plug to between 221 and 189 lbf.in (2.50 and 2.14 m.daN )

.
Post SB 72-0369

(e)

High Pressure Compressor Section Inspection

End of Post SB 72-0369
Pre SB 72-0369
(f)

High Pressure Compressor Section Inspection

End of Pre SB 72-0369
(g) Install shroud segment 3 (Ref. AMM TASK 72-24-01-400-801)

Subtask 72-30-00-420-052-A

J. Install the borescope plugs I, J, L, and M as follows:

NOTE: Borescope plug M is installed only on PRE-SB 72-0219 engines.

(1) Do a visual inspection of the borescope plugs and the borescope ports (Ref. AMM TASK 72-00-00-290-812).
(2) Remove the identification tag from the borescope plugs I, J, L, and M before the installation of the plug.
(3) Put CP2619Never Seez-Pure Nickel, Special on the borescope plug threads and the mating surfaces.
(4) Install the borescope plugs I, J, L, and M in the borescope ports:
(a) Put the plug into the correct port and hand tighten the inner thread.

NOTE: Make sure that the inner thread is correctly mated.

NOTE: While you install the inner thread, the outer thread is pushed up by the spring. Do not install both inner and outer threads at one time.

(b) TORQUE the inner thread of borescope plug to between 86 and 74 lbf.in (0.97 and 0.84 m.daN )

.
(c) Back the borescope plug off one-quarter turn, and TORQUE to between 20 and 15 lbf.in (0.23 and 0.17 m.daN )

above prevailing run on torque.
(d) Compress the spring and install the outer thread hand-tight.
(e) TORQUE the outer thread of borescope plug to between 221 and 189 lbf.in (2.50 and 2.14 m.daN )

Subtask 72-30-00-020-054-A

K. Remove the drive handle
(1) Remove the drive handle (Ref. AMM TASK 72-00-00-820-803).

5. Close-up
Subtask 72-30-00-410-053-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 thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR

Subtask 72-30-00-440-050-A

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

Subtask 72-30-00-410-054-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).

[Rev.10 from 2021] 2026.04.01 13:03:37 UTC