DOC AIRBUS | AMM A320FBorescope Inspection of the Combustion Chamber Liners and Dome Area (DAC engine NON /P only) [CFMB]
TASK 72-42-00-290-041-A-01
Borescope Inspection of the Combustion Chamber Liners and Dome Area (DAC engine NON /P only)
1. Reason for the Job
This TASK is applicable for NON/P engines equipped with a Double 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 72-42-00-941-065-A ** ON A/C NOT FOR ALL
Subtask 72-42-00-010-101-A ** ON A/C NOT FOR ALL
Subtask 72-42-00-410-095-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 02:42:39 UTC
Borescope Inspection of the Combustion Chamber Liners and Dome Area (DAC engine NON /P only)
1. Reason for the Job
This TASK is applicable for NON/P engines equipped with a Double 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 42 and 38 lbf.in (0.47 and 0.43 m.daN )  | |
| 856A1320 | 1 | BORESCOPE-KIT |
| 856A1322 | 1 | BORESCOPE-LIGHT SOURCE SET |
| 856A1323 | 1 | MONITOR, RESOLUTION BORESCOPE |
| REFERENCE | DESIGNATION |
|---|---|
| (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 72-52-00-290-001-B | Borescope Inspection of HPT Blades (from the front and the rear) |
| TASK 72-52-00-290-001-B-01 | Borescope Inspection of HPT Blades (from the front and the rear) |
| TASK 73-11-40-400-002-A | Installation of the Fuel Nozzle for SAC Engines |
| TASK 73-11-40-400-002-A-01 | Installation of the Fuel Nozzle for DAC Engines |
| 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 | |
Combustion Chamber (Inner and Outer Liner Inspection)Subtask 72-42-00-941-065-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 72-42-00-010-099-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 72-42-00-040-065-A ** ON A/C NOT FOR ALL Subtask 72-42-00-010-100-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 72-42-00-010-101-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 72-42-00-290-074-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 of the (856A1320P04/P05), into the ports and turn on the light source of the borescope-light source set (856A1322P03/P04).
(4) Turn the rigid borescope a full 360 degrees to inspect the domes 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 72-42-00-010-102-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 of the (856A1320P04/P05), into the ports and turn on the light source of the borescope-light source set (856A1322P03/P04).
(4) Turn the rigid borescope a full 360 degrees to inspect the domes 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 Assemblies (Spectacle Plate and Deflector) for: | | |
| A.Distortion of deflector | Any amount | |
| B.Radial crack in spectacle plate | Any number up to 1 in. (25.4 mm) length and not connected | See limit extensions (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 extensions (Ref. AMM TASK 72-00-00-200-025). |
| D.Connected cracks in spectacle plate | Not more than 1 radial crack 1 in. (25.4 mm) long with 1 circumferential crack 3 in. (76.2 mm) long | See limit extensions (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 | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| F.Radial crack in deflector | Any number up to 0.5 in. (12.7 mm) length | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| G.Circumferential cracks in deflector | Any number up to 0.75 in. (19.05 mm) | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| H.Connected cracks in deflector | Connection of any radial and circumferential cracks within limits of paragraphs F. and G. above. Limit is exceeded when third crack connects. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| J.Missing material from overhangs on deflector | 10 per dome, 1.0 in. (25.4 mm) wide x 0.5 in. (12.7 mm) maximum from original edge | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| K.Burn through holes | 3 per dome 1 in. (25.4 mm) x 1 in. (25.4 mm) maximum | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| 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. | | |
| A.Outer liner axial cracks | Any number across 1 Panel or less and up to 3 cracks across more than 1 panel but not longer than 3 panels | If up to 3 cracks extend 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 extensions (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. Up to 15 cracks across more than 1 panel but not longer than 2 panels. Up to 3 cracks across more than 2 panels but no longer than 3 panels | If up to 1 crack is across 4 panels and no material is missing more than 2 times the diameter (or 4 times the area) of a dilution hole and does not connect to a circumferential crack longer than 0.5 in. (12.7 mm), then inspect again in 750 cycles. |
| C.Inner liner support leg circumferential cracks (can include axial cracks that become circumferential) | Any amount of cracks that go part of the way across the leg is permitted with a maximum of 10 of the 30 legs cracked completely across the leg surface. | If there are more than 10 legs cracked completely across the leg surface, inspect the HPT blade trailing edge every 400 cycles (Ref. AMM TASK 72-52-00-290-001). |
| D.Circumferential cracks in inner liner | Any number up to one half of a dilution land in length separated by one non- cracked dilution land | See limit extensions (Ref. AMM TASK 72-00-00-200-025). NOTE: For the inner liner DAC-II, when reference is made to a dilution hole, or to the space between the dilution holes, called a dilution land, always refer to the dilution holes in panel 2 unless differently specified. |
| E.Circumferential cracks in outer liner | Length of cracks when added together must not be more than 20 percent of circumference. | If length of all cracks is between 20 percent and 40 percent of the circumference, do an inspection every 400 cycles. If cracks are more than 40 percent, see limit extensions (Ref. AMM TASK 72-00-00-200-025). NOTE: If the length of cracks when added together is greater than 20 percent, it is recommended that you do the borescope inspection on the cold side of the outer liner, if possible. Cracks measured on the cold side are through cracks. If possible, use cold side cracks to identify if the combustor is serviceable. |
| F.Connected cracks | (1) Up to 3 pairs of one axial and one circumferential crack that connect if the cracks are in the previous limits. (2) More than 3 pairs of connected cracks are permitted if the pairs of cracks are a minimum of two dilution lands apart. (3) A third connected crack connected to the above two cracks is permitted if the distance apart is less than the equivalent length of 2 dilution hole diameters away from the adjacent connected crack and in the opposite direction of the adjacent connected crack. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). NOTE: Cracks are identified as missing material as soon as the maximum gap equals the diameter of one dilution hole. |
| G.Burn through holes | 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. | |
| H.Distortion | Any amount within 0.5 in. (12.7 mm) of original contour | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| J.Missing overhangs | Total for both liners: Any amount | |
| 4.Centerbodies for: | | |
| A.Axial cracks | Any amount 0.25 in. (6.35 mm) from trailing edge, max length of 0.75 in. (19.05 mm) | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| B.Circumferential cracks | One crack per centerbody up to 0.25 in. (6.35 mm) circumferential length | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| C.Connecting Circumferential and axial cracks | One circumferential and one axial crack allowed within individual crack limits | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| D.Spalled or missing any amount coating | Any amount | |
| E.Burn areas | One area per centerbody up to 1 in. (25.4 mm) circumferential length by 0.50 in. (12.7 mm) axial length | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| F.Burn thru holes | Two areas per centerbody up to a max 0.50 in. (12.7 mm) circumferential length by 0.25 in. (6.35 mm) axial length spaced by a minimum of 0.25 in. (6.35 mm) | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| 5.Borescope ferrule welds for: | | |
| A.Cracks | Any amount | |
(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 72-42-00-290-075-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 (5) for each borescope and spark igniter location.
Subtask 72-42-00-410-094-A ** ON A/C NOT FOR ALL (1) Repeat paragraph 4.B.(1) thru (5) for each borescope and spark igniter location.
E. Install parts removed for borescope inspection.
(1) Apply a small amount ofCP2619 Never Seez-Pure Nickel, Special
.
(3) Safety the plugs withCP8001 lockwire 0.032 in. (0.8 mm) dia.
(4) If necessary, replace the O-ring on the fuel drain tube and install the tube to the fuel nozzle adjacent to the 6 o'clock borescope plug (Ref. AMM TASK 73-11-40-400-002).
(5) If necessary, remove the protective caps and install the spark igniters (Ref. AMM TASK 74-21-30-400-002)
Subtask 72-42-00-290-076-A ** ON A/C NOT FOR ALL (1) Apply a small amount of
NOTE: It may be necessary to mix a small amount of water with the magnesium hydroxide to make a paste.
(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 42 and 38 lbf.in (0.47 and 0.43 m.daN ) . (3) Safety the plugs with
(4) If necessary, replace the O-ring on the fuel drain tube and install the tube to the fuel nozzle adjacent to the 6 o'clock borescope plug (Ref. AMM TASK 73-11-40-400-002).
(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 72-42-00-790-059-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 72-42-00-410-095-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 72-42-00-440-065-A ** ON A/C NOT FOR ALL Subtask 72-42-00-410-096-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).