W DOC AIRBUS | AMM A320F

Detailed Inspection of the APU Overheat Sensing Elements

TASK 36-22-17-200-001-A
Detailed Inspection of the APU Overheat Sensing Elements

WARNING: MAKE SURE THAT THE SAFETY DEVICES AND THE WARNING NOTICES ARE IN POSITION BEFORE YOU START A TASK ON OR NEAR:
  • THE FLIGHT CONTROLS
  • THE FLIGHT CONTROL SURFACES
  • THE LANDING GEAR AND RELATED DOORS
  • COMPONENTS THAT MOVE.
MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.
WARNING: DO NOT TOUCH THE COMPONENT UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS.
WARNING: BEFORE YOU START WORK, YOU MUST PUT ON A SAFETY HARNESS AND ATTACH IT TO THE ACCESS PLATFORM. WITHOUT A SAFETY HARNESS, YOU CAN FALL. THIS CAN KILL YOU OR CAUSE YOU INJURY.
FIN: 12HF ** ON A/C NOT FOR ALL
1. Reason for the Job
Detailed inspection of the duct-leak/sensing element detection system, for example, after a duct leak warning.
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
1
ACCESS PLATFORM 3M (10 FT)
No specific
1
ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE
No specific
AR
SAFETY CLIP - CIRCUIT BREAKER
No specific
AR
WARNING NOTICE(S)
 B. Work Zones and Access Panels
ZONE/ACCESS
ZONE DESCRIPTION
161AW, 161BW, 161CW, 161DW, 312AR, 314AR
151DW, 151EW, 151HW, 151JW
151TW, 151UW, 151VW
 C. Referenced Information
REFERENCE
DESIGNATION
TASK 20-28-00-912-802-A
Electrical Bonding - General Maintenance Procedure
TASK 25-55-12-000-001-A
Removal of the Aft Cargo-Compartment Partition at FR65
TASK 25-55-12-400-001-A
Installation of the Aft Cargo-Compartment Partition at FR65
TASK 52-30-00-860-001-A
Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A
Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
F General Installation of the Duct
F General Installation of the Sensing Element
F Installation of the Sensing Element at STA3730/FR80
F Permitted Tolerances for the Sensing Element
F Typical Installation of the Sensing Element
3. Job Set-up
Subtask 36-22-17-865-053-A ** ON A/C NOT FOR ALL
A. Open, safety and tag this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
49VUAIR BLEED/X FEED/VALVE/BAT2HVD13
49VUAIR BLEED/ENG 1/CTL3HA1D12
49VUAIR BLEED/ENG 1/MONG2HA1D11
122VUAIR BLEED/ENG 2/CTL3HA2Z23
122VUAIR BLEED/ENG 2/MONG2HA2Z22
122VUAIR BLEED/X FEED VALVE/NORM1HVZ20
Subtask 36-22-17-860-051-A ** ON A/C NOT FOR ALL
B. Aircraft Maintenance Configuration
   (1) Put the WARNING NOTICE(S) in position:
  • in the cockpit on the engine control panel 115VU to tell persons not to start the engine(s),
  • in the cockpit on the AIR COND overhead control panel 30VU to tell persons not to push the APU BLEED pushbutton switch,
  • on the HP ground connector to tell persons not to pressurize the pneumatic system.
   (2) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position.
Subtask 36-22-17-010-051-A ** ON A/C NOT FOR ALL
C. Get Access
   (1) Get access to the APU overheat sensing elements between FR49 and FR70 from the AFT cargo compartment.
     (a) Open the AFT cargo compartment door (Ref. AMM TASK 52-30-00-860-001).
     (b) Remove the applicable access panels for the APU overheat sensing elements:
  • between the FR49 and FR52
    remove the access panel 151DW
  • between the FR52 and FR55
    remove the access panel 151EW
  • between the FR55 and FR58
    remove the access panel 151HW
  • between the FR58 and FR59
    remove the access panel 151JW
  • between the FR59 and FR62
    remove the access panel 161AW
  • between the FR62 and FR63
    remove the access panel 161BW
  • between the FR63 and FR65
    remove the access panel 161CW
  • between the FR65 and FR70
    remove the partition panel 161DW (Ref. AMM TASK 25-55-12-000-001).
   (2) Get access to the APU overheat sensing elements aft of FR70.
     (a) Put the ACCESS PLATFORM 3M (10 FT) below the rear fuselage.
     (b) Open the applicable access door for the APU overheat sensing elements:
  • between the FR70 and FR77
    open the access door 312AR,
  • aft of FR77
    open the access door 314AR.
Subtask 36-22-17-010-051-B ** ON A/C NOT FOR ALL
C. Get Access
   (1) Get access to the APU overheat sensing elements between FR53 and FR70 from the AFT cargo compartment.
     (a) Open the AFT cargo compartment door (Ref. AMM TASK 52-30-00-860-001).
     (b) Remove the applicable access panels for the APU overheat sensing elements:
  • between the FR53 and FR56
    remove the access panel 151TW
  • between the FR56 and FR58
    remove the access panel 151UW
  • between the FR58 and FR59
    remove the access panel 151VW
  • between the FR59 and FR62
    remove the access panel 161AW
  • between the FR62 and FR63
    remove the access panel 161BW
  • between the FR63 and FR65
    remove the access panel 161CW
  • between the FR65 and FR70
    remove the partition panel 161DW (Ref. AMM TASK 25-55-12-000-001).
   (2) Get access to the APU overheat sensing elements aft of FR70.
     (a) Put the ACCESS PLATFORM 3M (10 FT) below the rear fuselage.
     (b) Open the applicable access door for the APU overheat sensing elements:
  • between the FR70 and FR77
    open the access door 312AR,
  • aft of FR77
    open the access door 314AR.
4. Procedure
Subtask 36-22-17-210-051-A ** ON A/C NOT FOR ALL
A. Inspection of the Overheat Sensing Elements
   (1) Examine the overheat sensing elements and the element connection assemblies for the correct condition. The element tubing must not be twisted and the surface must be free of damage other than the limits that follow:
     (a) The maximum permitted depth of abrasion or dents is 0.05 mm (0.0020 in.).
     (b) The minimum permitted tube diameter at a dent is 1.78 mm (0.0701 in.).
   (2) Make sure that the clearance between the sensing elements and the duct is a minimum of 12.7 mm (0.50 in.), measured along the full length of the sensing element.
F Typical Installation of the Sensing Element ** ON A/C NOT FOR ALL
   (3) Do an inspection of the sensing elements to make sure that they are installed on the outer side of the insulation.
   (4) Make sure that the clearance between the sensing elements and the duct insulation is the same as at the mounting brackets.
   (5) Make sure that the sensing elements are installed in the permitted tolerances.
F Permitted Tolerances for the Sensing Element ** ON A/C NOT FOR ALL
   (6) Make sure that each clamp has a silicon rubber grommet.
   (7) Make sure that each mounting bracket, installed on the duct, has a spacer.
   (8) Make sure that the sensing element at FR80 is installed.
F Installation of the Sensing Element at STA3730/FR80 ** ON A/C NOT FOR ALL
   (9) Make sure that each mounting clamp is in the correct condition and has no corrosion.
   (10) Make sure that the bonding straps are correctly attached (Ref. AMM TASK 20-28-00-912-802).
   (11) Make sure that the lockwires are correctly installed on the connection of the sensing elements.
   (12) Make sure that the duct insulation is not damaged and correctly installed.
   (13) Make sure that the sensing elements have no cracks, nicks, sharp edges, bonds chafing or corrosion.
5. Close-up
Subtask 36-22-17-410-052-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) Install the access panels as necessary:
     (a) For the APU overheat sensing elements between the FR49 and FR52:
  • Install the access panel 151DW.
     (b) For the APU overheat sensing elements between the FR52 and FR55:
  • Install the access panel 151EW.
     (c) For the APU overheat sensing elements between the FR55 and FR58:
  • Install the access panel 151HW.
     (d) For the APU overheat sensing elements between FR58 and FR59:
  • Install the access panel 151JW.
     (e) For the APU overheat sensing elements between the FR59 and FR62:
  • Install the access panel 161AW.
     (f) For the APU overheat sensing elements between the FR62 and FR63:
  • Install the access panel 161BW.
     (g) For the APU overheat sensing elements between the FR63 and FR65:
  • Install the access panel 161CW.
   (3) For the APU overheat sensing elements between the FR65 and FR70:
   (4) Close the AFT cargo compartment door (Ref. AMM TASK 52-30-00-860-002).
   (5) For the APU overheat sensing elements between the FR70 and FR77:
  • Close the access door 312AR.
   (6) For the APU overheat sensing elements aft of FR77:
  • Close the access door 314AR.
Subtask 36-22-17-410-052-B ** 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) Install the access panels as necessary:
   (3) For the APU overheat sensing elements between the FR53 and FR56:
  • Install the access panel 151TW.
   (4) For the APU overheat sensing elements between the FR56 and FR58:
  • Install the access panel 151UW.
   (5) For the APU overheat sensing elements between the FR58 and FR59:
  • Install the access panel 151VW.
   (6) For the APU overheat sensing elements between the FR59 and FR62:
  • Install the access panel 161AW.
   (7) For the APU overheat sensing elements between FR62 and FR63:
  • Install the access panel 161BW.
   (8) For the APU overheat sensing elements between the FR63 and FR65:
  • Install the access panel 161CW.
   (9) For the APU overheat sensing elements between the FR65 and FR70:
   (10) Close the AFT cargo compartment door (Ref. AMM TASK 52-30-00-860-002).
   (11) For the APU overheat sensing elements between the FR70 and FR77:
  • Close the access door 312AR.
   (12) For the APU overheat sensing elements aft of FR77:
  • Close the access door 314AR.
Subtask 36-22-17-865-054-A ** ON A/C NOT FOR ALL
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
49VUAIR BLEED/X FEED/VALVE/BAT2HVD13
49VUAIR BLEED/ENG 1/CTL3HA1D12
49VUAIR BLEED/ENG 1/MONG2HA1D11
122VUAIR BLEED/ENG 2/CTL3HA2Z23
122VUAIR BLEED/ENG 2/MONG2HA2Z22
122VUAIR BLEED/X FEED VALVE/NORM1HVZ20
Subtask 36-22-17-942-054-A ** ON A/C NOT FOR ALL
C. Put the aircraft back to its initial configuration.
   (1) Remove the access platform(s).
   (2) Remove the WARNING NOTICE(S).
[Rev.10 from 2021] 2026.04.01 01:17:22 UTC
"Aviabrain" 2025