DOC AIRBUS | AMM A320FVisually Examine the Thrust Reverser - Allowable Damage Data [IAE]
TASK 78-32-00-200-015-A
Visually Examine the Thrust Reverser - Allowable Damage Data
1. Reason for the Job
General - Allowable damage data are intended to permit an operator to determine whether a damaged nacelle component may be returned to service without repair. Damage permitted by these data will have no significant effect on the strength or fatigue life of the structure, which will still be able to fulfill its design function. The types of allowable damage permitted are defined and brief descriptions are given of the cleanup procedures needed to either prevent damage propagation or improve the aerodynamic smoothness of the damaged part.
Material Types - The basic material used in the construction of the thrust reverser components is aluminium. It makes up the bonded panel construction of the thrust reverser translating sleeve and the sheet metal and bonded panel construction of the C-duct inner barrel. In addition, the outer skin of the translating sleeve is made up of layered plies of graphite and fiberglass material.
Damage - All damage limits assume that exposed edges do not extend above the skin contour. Any such damage should be reworked to remove or feather the extensions. Holes and cracks in the pressure boundaries must be sealed with applicable tape material. Allowable damage is classified as either unlimited usage or time limited.
Unlimited usage damage is defined as minor damage which does not affect the structural integrity or functional capability of the component and which needs no repairs over the aircraft design life.
Time limited damage is defined as minor damage which does not affect the structural integrity of the component in normal operation, but could reduce the design life of the component. Therefore, damage must be permanently repaired no later than the next maintenance C check. The location and size of the damage is to be noted and checked at each subsequent A check to make sure that the damage has not grown beyond the time limited damage allowances.
Damage Types - The types of allowable damage permitted on the thrust reverser components are defined below. They apply only to the parent material and do not include damage to surface finishes such as paint.
Abrasion - An abrasion is a damage area which results in a cross sectional area change because the area was scuffed, rubbed, scraped or had other surface erosion. An abrasion usually appears rough and irregular.
Gouge - A gouge is a damage area of any size which results in a cross sectional area change. It is usually caused by contact with a relatively sharp object which produces a continuous, sharp or smooth channel-like groove in the material.
Nick - A nick is a local gouge with sharp edges. Consider a series of nicks in a line to be a gouge.
Scratch - A scratch is a line of damage in the material and results in a cross sectional area change. It is usually caused by contact with a very sharp object.
Crack - A crack is a partial fracture or complete break in the material and produces a most significant cross sectional area change. It usually appears as an irregular line.
Dent - A dent is damage area which is depressed with respect to its normal contour. There is no change in the cross sectional area. Area boundaries are smooth. Its form is usually the result of contact with a smoothly contoured object.
Rip/Tear (Woven Wire) - A rip or a tear in the woven wire of an acoustic bonded panel is a sharp continuous separation of the wire fibers.
Hole - A hole is a complete penetration of the material.
Disbond - A disbond is a separation of the face sheet from the honeycomb core of a bonded panel.
Delamination - A delamination is the separation of two laminate plies or faying surfaces.
Missing Rivet - Absence of rivet from the fastener hole.
Loose Rivet - Ineffective fastener.
This task gives the procedure for the inspection of the thrust reverser to determine allowable damage.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 78-32-00-941-057-A ** ON A/C NOT FOR ALL
Subtask 78-32-00-210-054-A ** ON A/C NOT FOR ALL
Subtask 78-32-00-410-065-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 04:08:15 UTC
Visually Examine the Thrust Reverser - Allowable Damage Data
1. Reason for the Job
General - Allowable damage data are intended to permit an operator to determine whether a damaged nacelle component may be returned to service without repair. Damage permitted by these data will have no significant effect on the strength or fatigue life of the structure, which will still be able to fulfill its design function. The types of allowable damage permitted are defined and brief descriptions are given of the cleanup procedures needed to either prevent damage propagation or improve the aerodynamic smoothness of the damaged part.
Material Types - The basic material used in the construction of the thrust reverser components is aluminium. It makes up the bonded panel construction of the thrust reverser translating sleeve and the sheet metal and bonded panel construction of the C-duct inner barrel. In addition, the outer skin of the translating sleeve is made up of layered plies of graphite and fiberglass material.
Damage - All damage limits assume that exposed edges do not extend above the skin contour. Any such damage should be reworked to remove or feather the extensions. Holes and cracks in the pressure boundaries must be sealed with applicable tape material. Allowable damage is classified as either unlimited usage or time limited.
Unlimited usage damage is defined as minor damage which does not affect the structural integrity or functional capability of the component and which needs no repairs over the aircraft design life.
Time limited damage is defined as minor damage which does not affect the structural integrity of the component in normal operation, but could reduce the design life of the component. Therefore, damage must be permanently repaired no later than the next maintenance C check. The location and size of the damage is to be noted and checked at each subsequent A check to make sure that the damage has not grown beyond the time limited damage allowances.
Damage Types - The types of allowable damage permitted on the thrust reverser components are defined below. They apply only to the parent material and do not include damage to surface finishes such as paint.
Abrasion - An abrasion is a damage area which results in a cross sectional area change because the area was scuffed, rubbed, scraped or had other surface erosion. An abrasion usually appears rough and irregular.
Gouge - A gouge is a damage area of any size which results in a cross sectional area change. It is usually caused by contact with a relatively sharp object which produces a continuous, sharp or smooth channel-like groove in the material.
Nick - A nick is a local gouge with sharp edges. Consider a series of nicks in a line to be a gouge.
Scratch - A scratch is a line of damage in the material and results in a cross sectional area change. It is usually caused by contact with a very sharp object.
Crack - A crack is a partial fracture or complete break in the material and produces a most significant cross sectional area change. It usually appears as an irregular line.
Dent - A dent is damage area which is depressed with respect to its normal contour. There is no change in the cross sectional area. Area boundaries are smooth. Its form is usually the result of contact with a smoothly contoured object.
Rip/Tear (Woven Wire) - A rip or a tear in the woven wire of an acoustic bonded panel is a sharp continuous separation of the wire fibers.
Hole - A hole is a complete penetration of the material.
Disbond - A disbond is a separation of the face sheet from the honeycomb core of a bonded panel.
Delamination - A delamination is the separation of two laminate plies or faying surfaces.
Missing Rivet - Absence of rivet from the fastener hole.
Loose Rivet - Ineffective fastener.
This task gives the procedure for the inspection of the thrust reverser to determine allowable damage.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | ACCESS PLATFORM 2M (6 FT) |
| No specific | AR | WARNING NOTICE(S) |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| FOR [1000EM1] (ENGINE-1) | |
| 437AL, 438AR, 451AL, 452AR | |
| FOR [1000EM2] (ENGINE-2) | |
| 447AL, 448AR, 461AL, 462AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-13-00-010-010-A | Opening of the Fan Cowls 437AL(447AL),438AR(448AR) |
| TASK 71-13-00-410-010-A | Closing of the Fan Cowls 437AL(447AL),438AR(448AR) |
| TASK 78-30-00-040-012-A | Deactivation of the Thrust Reverser Hydraulic Control Unit (HCU) for Ground Maintenance |
| TASK 78-30-00-440-012-A | Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after Ground Maintenance |
| TASK 78-31-00-710-041-A | Operational Test of the Thrust Reverser System with the CFDS |
| TASK 78-31-00-710-041-A-02 | Operational test of the Thrust Reverser without the CFDS and Engine Running |
| TASK 78-32-00-010-010-A | Opening of the Thrust Reverser Halves |
| TASK 78-32-00-410-010-A | Closing of the Thrust Reverser Halves |
| TASK 78-32-00-860-010-A | Manual Extension of the Thrust Reverser Translating Sleeves |
| TASK 78-32-00-860-011-A | Manual Retraction of the Thrust Reverser Translating Sleeves |
Translating CowlSubtask 78-32-00-941-057-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 78-32-00-010-067-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 cowls (Ref. AMM TASK 71-13-00-010-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put the ACCESS PLATFORM 2M (6 FT) in position.
Subtask 78-32-00-040-058-A ** ON A/C NOT FOR ALL (1) Open the fan cowls (Ref. AMM TASK 71-13-00-010-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put the ACCESS PLATFORM 2M (6 FT) in position.
C. Deactivate the Thrust Reverser.
Subtask 78-32-00-980-054-A ** ON A/C NOT FOR ALL 4. ProcedureWARNING:
MAKE SURE THAT THE THRUST REVERSER HYDRAULIC CONTROL UNIT (HCU) IS DEACTIVATED BEFORE YOU DO WORK ON OR AROUND THE THRUST REVERSER. IF THE HCU IS NOT DEACTIVATED, THERE IS A RISK OF UNWANTED THRUST REVERSER OPERATION WHICH CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.
(1) Deactivate the thrust reverser Hydraulic Control Unit (HCU) (Ref. AMM TASK 78-30-00-040-012). Subtask 78-32-00-210-054-A ** ON A/C NOT FOR ALL
A. Examine the translating sleeve
(1) Abrasion, Crack, Delamination, Disbond, Gouge, Scratch, Hole, Dent and Nick
(a) Refer toNSRM 543000 Allowable Damage.
(2) Blistered paint
(a) Zone TS1 - Allowed in aft latch area. Unlimited use.
(3) Missing or loose rivet
(a) Refer toNSRM 543000 Allowable Damage.
Subtask 78-32-00-010-068-A ** ON A/C NOT FOR ALL (1) Abrasion, Crack, Delamination, Disbond, Gouge, Scratch, Hole, Dent and Nick
(a) Refer to
(2) Blistered paint
(a) Zone TS1 - Allowed in aft latch area. Unlimited use.
(3) Missing or loose rivet
(a) Refer to
B. Open the thrust reverser halves (Ref. AMM TASK 78-32-00-010-010):
(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR
Subtask 78-32-00-210-055-A ** ON A/C NOT FOR ALL (1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR
C. Examine the C-duct fixed structure
(1) Disbond, Dent, Gouge, Nick, Scratch, Partial and Full Penetration
(a) Refer toNSRM 543000 Allowable Damage.
5. Close-up(1) Disbond, Dent, Gouge, Nick, Scratch, Partial and Full Penetration
(a) Refer to
Subtask 78-32-00-410-065-A ** ON A/C NOT FOR ALL
A. Close Access
(1) Close the thrust reverser halves (Ref. AMM TASK 78-32-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR
Subtask 78-32-00-980-055-A ** ON A/C NOT FOR ALL Subtask 78-32-00-440-056-A ** ON A/C NOT FOR ALL Subtask 78-32-00-410-066-A ** ON A/C NOT FOR ALL (1) Close the thrust reverser halves (Ref. AMM TASK 78-32-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR
D. Close Access
(1) Close the fan cowls (Ref. AMM TASK 71-13-00-410-010):
(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).
Subtask 78-32-00-710-065-A ** ON A/C NOT FOR ALL (1) Close the fan cowls (Ref. AMM TASK 71-13-00-410-010):
(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).
E. Operational Test
(1) Do an operational test of the thrust reverser system (Ref. AMM TASK 78-31-00-710-041).
(1) Do an operational test of the thrust reverser system (Ref. AMM TASK 78-31-00-710-041).
NOTE: As an alternative procedure, you can do the operational test without the CFDS (Ref. AMM TASK 78-31-00-710-041).