Borescope Inspection of the Combustion Chamber Liners and Dome Area (SAC engine) [CFMB]
TASK 72-42-00-290-041-A
Borescope Inspection of the Combustion Chamber Liners and Dome Area (SAC engine)
This TASK is applicable for NON/P, /P, /3 and /3 PIP engines equipped with a Single Annular Combustor chamber.
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 72-42-00-941-053-A ** ON A/C NOT FOR ALL
Subtask 72-42-00-010-060-A ** ON A/C NOT FOR ALL
Subtask 72-42-00-410-057-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 02:42:37 UTC
Borescope Inspection of the Combustion Chamber Liners and Dome Area (SAC engine)
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.
1. Reason for the JobThis TASK is applicable for NON/P, /P, /3 and /3 PIP engines equipped with a Single Annular Combustor chamber.
NOTE: Inspection of the combustion chamber is limited to the areas that can be seen with a rigid borescope, at the 1, 3, 6 and 10 o'clock borescope ports, and at the 2 spark igniter ports.
The borescope ports at the 1, 3, 6, and 10 o'clock positions are located immediately in front of the fuel manifold. These ports and the 2 spark igniter ports permit the borescope inspection of the combustion chamber and the HPT nozzle.
2. Job Set-up InformationThe borescope ports at the 1, 3, 6, and 10 o'clock positions are located immediately in front of the fuel manifold. These ports and the 2 spark igniter ports permit the borescope inspection of the combustion chamber and the HPT nozzle.
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | ACCESS PLATFORM 1M(3 FT) |
| No specific | AR | CAP - PROTECTION |
| 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 ) ![]() | |
| No specific | Torque wrench: range to between 135 and 120 lbf.in (1.53 and 1.36 m.daN ) ![]() | |
| 856A1320 | 1 | BORESCOPE-KIT |
| 856A1322 | 1 | BORESCOPE-LIGHT SOURCE SET |
| 856A1323 | 1 | MONITOR, RESOLUTION BORESCOPE |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP1064) | milk of magnesia |
| (Material No.CP2101) | graphite grease |
| (Material No.CP2619) | Never Seez-Pure Nickel, Special |
| (Material No.CP8001) | lockwire 0.032 in. (0.8 mm) dia. |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 400 | POWER PLANT, NACELLES AND PYLONS |
| FOR [1000EM1] (ENGINE-1) | |
| 437AL, 438AR, 451AL, 452AR | |
| FOR [1000EM2] (ENGINE-2) | |
| 447AL, 448AR, 461AL, 462AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-13-00-010-040-B | Opening of the Fan Cowl Doors |
| TASK 71-13-00-410-040-B | Closing of the Fan Cowl Doors |
| TASK 72-00-00-200-025-A | Over-Serviceable-Limit Extensions |
| TASK 72-00-00-200-025-A-01 | Over-Serviceable-Limit Extensions |
| TASK 72-42-00-290-006-A | Borescope Inspection of the Outer Side of the Combustion Chamber Outer Liners (SAC engine) |
| TASK 72-42-00-290-006-A-01 | Borescope Inspection of the Outer Side of the Combustion Chamber Outer Liners (DAC engine) |
| TASK 73-11-40-790-002-A | Leak Check of the Fuel Nozzles for SAC Engines |
| TASK 73-11-40-790-002-A-01 | Leak Check of the Fuel Nozzles for DAC Engines |
| TASK 74-21-30-000-002-A | Removal of the Spark Igniter |
| TASK 74-21-30-400-002-A | Installation of the Spark Igniter |
| TASK 78-30-00-081-041-B | Make the Thrust Reverser Serviceable after Maintenance |
| TASK 78-30-00-481-041-B | Make the Thrust Reverser Unserviceable for Maintenance |
| TASK 78-36-00-010-040-B | Opening of the Thrust Reverser Doors |
| TASK 78-36-00-410-040-B | Closing of the Thrust Reverser Doors |
| NTM 720000 | |
Subtask 72-42-00-941-053-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) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 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) to tell persons not to energize the FADEC 1(2).
Subtask 72-42-00-010-058-A ** ON A/C NOT FOR ALL (1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 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) to tell persons not to energize the FADEC 1(2).
B. Get Access
(1) Open the fan cowl doors: (Ref. AMM TASK 71-13-00-010-040)
(2) FOR [1000EM1] (ENGINE-1)
437AL, 438AR
(3) FOR [1000EM2] (ENGINE-2)
447AL, 448AR.
(4) Put the ACCESS PLATFORM 1M(3 FT) in position.
Subtask 72-42-00-040-053-A ** ON A/C NOT FOR ALL Subtask 72-42-00-010-059-A ** ON A/C NOT FOR ALL (1) Open the fan cowl doors: (Ref. AMM TASK 71-13-00-010-040)
(2) FOR [1000EM1] (ENGINE-1)
437AL, 438AR
(3) FOR [1000EM2] (ENGINE-2)
447AL, 448AR.
(4) Put the ACCESS PLATFORM 1M(3 FT) in position.
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(1) FOR [1000EM1] (ENGINE-1)
451AL, 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL, 462AR.
Subtask 72-42-00-010-060-A ** ON A/C NOT FOR ALL
A. Remove parts before borescope inspection.
(1) Remove the borescope plugs from the approximate 3 and 10 o'clock positions on the combustion case.
Subtask 72-42-00-290-054-A ** ON A/C NOT FOR ALL (1) Remove the borescope plugs from the approximate 3 and 10 o'clock positions on the combustion case.
B. Do a Borescope Inspection
(1) Use the 856A1323 MONITOR, RESOLUTION BORESCOPE (856A1323G01) to make sure the borescope and the light source are serviceable. See the Non-Destructive Test Manual for this procedure NTM 720000.
(2) Connect the fiber light cable to the 856A1320 BORESCOPE-KIT (856A1320P04/P05) and to the port on the 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P03/P04/P07).
(3) Put the rigid borescope (856A1320P04/P05), into the ports and turn on the light source of the borescope-light source set (856A1322P03 or P04).
(4) Turn the rigid borescope a full 360 degrees to inspect the dome of the combustion chamber, fuel nozzles, inner and outer liners and aft sections. Adjust the borescope equipment to obtain maximum clarity of view.
(5) Inspect the following:
(6) When the inspection is complete, turn off the light source and remove the borescope.
(7) If any defects are found then remove additional borescope plugs and the spark igniters to inspect all of the combustion chamber.
If no defects are found, install parts removed for borescope inspection.
Subtask 72-42-00-010-064-A ** ON A/C NOT FOR ALL (1) Use the 856A1323 MONITOR, RESOLUTION BORESCOPE (856A1323G01) to make sure the borescope and the light source are serviceable. See the Non-Destructive Test Manual for this procedure NTM 720000.
(2) Connect the fiber light cable to the 856A1320 BORESCOPE-KIT (856A1320P04/P05) and to the port on the 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P03/P04/P07).
(3) Put the rigid borescope (856A1320P04/P05), into the ports and turn on the light source of the borescope-light source set (856A1322P03 or P04).
(4) Turn the rigid borescope a full 360 degrees to inspect the dome of the combustion chamber, fuel nozzles, inner and outer liners and aft sections. Adjust the borescope equipment to obtain maximum clarity of view.
(5) Inspect the following:
| INSPECT/CHECK | MAXIMUM SERVICEABLE LIMITS | REMARKS |
|---|---|---|
| 1.All surfaces for: | | |
| A.Discoloration | Any amount | |
| B.Carbon Accumulation | Any amount | |
| C.Missing, chipped or spalled areas of thermal barrier coating | Any amount | |
| 2.Dome Assembly (Spectacle Plate, Deflector and Sleeve) for: | | |
| A.Distortion of deflector or sleeve | Any amount | |
| B.Radial crack in spectacle plate | Any number up to 2 in. (50.8 mm) length and not connected to each other. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| C.Circumferential crack in spectacle plate | Any number up to 3 in. (76.2 mm) length separated by 6 in. (152.4 mm). | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| D.Connected cracks in spectacle plate | Not more than 1 radial crack 2 in. (50.80 mm) long with 1 circumferential crack 3 in. (76.20 mm) long separated by 6 in. (152.4 mm). | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| E.Missing material from spectacle plate | Max. 0.06 in. (1.52 mm) x 0.06 in. (1.52 mm) at intersection of connected crack. Multiple axial and circumferential cracks that connect if cracks: | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| F.Radial crack in deflector or sleeve | Any number up to 0.5 in. (12.7 mm) length. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| G.Circumferential cracks in deflector or sleeve | Any number up to 0.75 in. (19.05 mm). | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| H.Connected cracks in deflector or sleeve | Connection of any radial and circumferential cracks within limits of paragraphs F. and G. above. Limit is exceeded when third crack connects. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| J.Missing material from extensions on deflector | ||
| K.Missing material from extensions on sleeve | Any amount up to 0.2 in. (5.08 mm) maximum depth. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| L.Burn through holes | 3 per dome 1 in. (25.4 mm) x 1 in. (25.4 mm) maximum. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| M.Fuel nozzles for dislodged wear sleeves | Not serviceable | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| N.Notch on the edge of the spectacle plate. | One notch on edge of spectacle plate at any cup location can exist. | |
| P. Cracks and missing material from the secondary swirl nozzle venturi | (1) Any number of secondary swirl nozzle venturis with indications (cracks) permitted. (2) Any number of secondary swirl nozzle venturis with total missing material at each venturi up to 0.100 in. (2.5 mm) in width permitted. | |
| 3.Inner and outer liners for: NOTE: Axial cracks can turn circumferential for a short distance (less than one dilution land in length). In this condition, you must think of the crack of as one continuous axial crack. | | NOTE: For all non /3 engines: For the dome bands and panel 2 of the inner and outer liner, use the dilution lands (the distance between the edges of the dilution holes) on panel 1. For the panels 4 and 5 on the outer liner and panel 4 of the inner liner, use the dilution lands on panel 3. NOTE: For /3 and /3 PIP engines: For the dome bands of the inner and outer liner, use the dilution lands (the distance between the edges of the dilution holes) on panel 1. For the panels 3 to 5 on the outer liner and panels 3 and 4 on the inner liner, use the dilution lands on panel 2. |
| A.Outer liner axial cracks | Any number across 1 Panel or less and up to 4 cracks across more than 1 panel but not longer than 3 panels. | If a crack extends across more than 3 panels, borescope the outer side of the outer liner in the crack locations (Ref. AMM TASK 72-42-00-290-006). See limit extension (Ref. AMM TASK 72-00-00-200-025). NOTE: When applying limits, the dome band is interpreted as a panel. |
| B.Inner liner axial cracks | Any number across 1 panel or less and up to 4 cracks across more than 1 panel but not longer than 2 panels. | If up to 1 crack is across 4 panels and no material is missing more than 3 times the diameter of a dilution hole and does not connect to a circumferential crack longer than 0.5 in. (12.7 mm), then reinspect in 750 cycles. See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| C.Circumferential cracks | There is no limit to the number with these conditions: The cracks are no longer than 2 dilution lands. There are no more than 2 adjacent cracks in a dilution land. The cracks are separated by a minimum of 3 dilution lands that do not have cracks. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). NOTE: For all non /3 engines: For the dome bands and panel 2 of the inner and outer liner, use the dilution lands (the distance between the edges of the dilution holes) on panel 1. For the panels 4 and 5 on the outer liner and panel 4 of the inner liner, use the dilution lands on panel 3. NOTE: For /3 and /3 PIP engines: For the dome bands of the inner and outer liner, use the dilution lands (the distance between the edges of the dilution holes) on panel 1. For the panels 3 to 5 on the outer liner and panels 3 and 4 on the inner liner, use the dilution lands on panel 2. |
| D.Connected cracks | Connection of any axial and circumferential cracks up to max limits of paragraphs A. B. and C. above. Limit is exceeded when third crack connects. Multiple axial and circumferential cracks that connect if cracks: a. Contained in one panel. b. Contained in one dilution land area. c. There are not more than two locations in the adjacent panels that are axially aligned. d. The locations are separated by a minimum of three dilution lands that do not have cracks. e. There are not more than five locations with connected cracks. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| E.Burn through or missing material | Per liner, any number of holes are permitted with these conditions: (1) There are not more than 2 holes in adjacent panels that are axially aligned. (2) The maximum size of any hole is not more than 5 times the size of a dilution hole. (3) The total area of burn through is not to exceed 15 times the size of a dilution hole. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| F.Missing overhangs | Per liner: 14 areas each 2 times the size of a dilution hole providing maximum axial alignment of distress is 3 adjacent panels. | See limits extensions (Ref. AMM TASK 72-00-00-200-025). |
| G.Distortion | Any amount within 0.5 in. (12.7 mm) of original contour. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
(7) If any defects are found then remove additional borescope plugs and the spark igniters to inspect all of the combustion chamber.
If no defects are found, install parts removed for borescope inspection.
C. Remove parts before additional borescope inspection.
(1) Remove the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug.
(3) Remove both spark igniters (Ref. AMM TASK 74-21-30-000-002).
(4) Install CAP - PROTECTION on the leads and the spark igniters.
Subtask 72-42-00-290-056-A ** ON A/C NOT FOR ALL (1) Remove the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug.
NOTE: If you remove the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug, you will be required to perform a leak check after this inspection. Use the 6 o'clock borescope port only if necessary.
(2) Remove the borescope plugs from the approximate 1 and 6 o'clock positions. (3) Remove both spark igniters (Ref. AMM TASK 74-21-30-000-002).
(4) Install CAP - PROTECTION on the leads and the spark igniters.
D. Do a borescope inspection of the entire combustion chamber.
(1) Repeat paragraph 4.B.(1) thru 4.B.(5) for each borescope and spark igniter location.
Subtask 72-42-00-410-059-A ** ON A/C NOT FOR ALL (1) Repeat paragraph 4.B.(1) thru 4.B.(5) for each borescope and spark igniter location.
E. Install parts removed for borescope inspection.
(1) Apply a small amount of graphite grease (Material No.CP2101) orCP2619 Never Seez-Pure Nickel, Special or milk of magnesia (Material No.CP1064) to the borescope plug threads and pressure faces.
(2) Install the borescope plugs.
.
(3) Safety the plugs withCP8001 lockwire 0.032 in. (0.8 mm) dia.
(4) If necessary, install the fuel drain tube to the fuel nozzle adjacent to the six o'clock borescope plug. TORQUE the coupling nuts on the fuel drain tube to between 135 and 120 lbf.in (1.53 and 1.36 m.daN )
and safety with CP8001 lockwire 0.032 in. (0.8 mm) dia.
(5) If necessary, remove the protective caps and install the spark igniters (Ref. AMM TASK 74-21-30-400-002)
Subtask 72-42-00-290-062-A ** ON A/C NOT FOR ALL (1) Apply a small amount of graphite grease (Material No.CP2101) or
(2) Install the borescope plugs.
CAUTION:
BE SURE TO INSTALL THE CORRECT BORESCOPE PLUGS. THE COMBUSTOR BORESCOPE PLUGS DO NOT HAVE A STEM FEATURE. INADVERTENT INSTALLATION OF BORESCOPE PLUGS WITH STEMS FROM OTHER LOCATIONS WILL RESULT IN THE STEM FEATURE BEING BURNED AWAY BY COMBUSTION GASES.
(a) Install the borescope plugs and TORQUE to between 63 and 57 lbf.in (0.71 and 0.64 m.daN )
. (3) Safety the plugs with
(4) If necessary, install the fuel drain tube to the fuel nozzle adjacent to the six o'clock borescope plug. TORQUE the coupling nuts on the fuel drain tube to between 135 and 120 lbf.in (1.53 and 1.36 m.daN )
and safety with (5) If necessary, remove the protective caps and install the spark igniters (Ref. AMM TASK 74-21-30-400-002)
F. If necessary, do the borescope inspection of the outer side of the outer liner to confirm the extent of outer liner axial cracks (Ref. AMM TASK 72-42-00-290-006).
Subtask 72-42-00-790-051-A ** ON A/C NOT FOR ALL G. Do a fuel nozzle leak check.
(1) If you removed the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug, do a fuel nozzle leak check (Ref. AMM TASK 73-11-40-790-002).
5. Close-up(1) If you removed the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug, do a fuel nozzle leak check (Ref. AMM TASK 73-11-40-790-002).
Subtask 72-42-00-410-057-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.
(3) Remove the access platform(s).
Subtask 72-42-00-440-055-A ** ON A/C NOT FOR ALL Subtask 72-42-00-410-058-A ** ON A/C NOT FOR ALL (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.
(3) Remove the access platform(s).
Combustion Chamber (Inner and Outer Liner Inspection)