W DOC AIRBUS | AMM A320F

Detailed Inspection of the APU Overheat Sensing-Elements

TASK 36-22-17-200-803-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.
1. Reason for the Job
Self explanatory
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
151DW, 151EW, 151HW, 151JW, 161AW, 161BW, 161CW, 161DW, 312AR, 314AR
 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 Permitted Tolerances for the Sensing Element
F Typical Installation of the Sensing Element
3. Job Set-up
Subtask 36-22-17-865-057-A
A. Open, safety and tag this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C ALL
49VUAIR BLEED/X FEED/VALVE/BAT2HVD13
49VUAIR BLEED/ENG 2/MONG3HA2D12
49VUAIR BLEED/ENG 1/CTL2HA1D11
122VUAIR BLEED/ENG 1/MONG3HA1Z23
122VUAIR BLEED/ENG 2/CTL2HA2Z22
122VUAIR BLEED/X FEED VALVE/NORM1HVZ20
Subtask 36-22-17-860-053-A
B. Aircraft Maintenance Configuration
   (1) Put the WARNING NOTICE(S) in position:
  • In the cockpit, on engine control panel 115VU, to tell persons not to start the engine(s)
  • In the cockpit, on 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.
Subtask 36-22-17-010-053-A
C. Get Access
   (1) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position.
   (2) 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 to get access to the APU overheat sensing-elements:
       1 Between FR49 and FR52:
  • Remove access panel 151DW.
       2 Between FR52 and FR55:
  • Remove access panel 151EW.
       3 Between FR55 and FR58:
  • Remove access panel 151HW.
       4 Between FR58 and FR59:
  • Remove access panel 151JW.
       5 Between FR59 and FR62:
  • Remove access panel 161AW.
       6 Between FR62 and FR63:
  • Remove access panel 161BW.
       7 Between FR63 and FR65
  • Remove access panel 161CW.
       8 Between FR65 and FR70:
   (3) 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:
       1 Between FR70 and FR77:
       2 Aft of FR77:
4. Procedure
Subtask 36-22-17-210-053-A
A. Inspection of the Overheat Sensing Elements
   (1) Examine the overheat sensing elements and the element connection assemblies for correct condition. The element tubing must not be twisted and the damage must be in the limits that follow:
     (a) The maximum permitted depth of abrasions 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 12.7 mm (0.50 in.) minimum, measured along the full length of the sensing element.
F Typical Installation of the Sensing Element
   (3) Do an inspection of the elements to make sure that they are installed out of the insulation.
   (4) Make sure that the clearance between the elements and the duct insulation is the same as at the mounting brackets.
   (5) Make sure that the sensing elements are installed with the permitted tolerance.
F Permitted Tolerances for the Sensing Element
   (6) Make sure that each clamp has a silicon rubber grommet.
   (7) Make sure that each mounting bracket, that is installed directly in the duct, has a spacer.
   (8) Make sure that the element at FR80 is installed correctly.
F General Installation of the Duct
   (9) Make sure that each mounting bracket and clamp is the correct condition and has no corrosion.
   (10) Make sure that the bonding straps are correctly installed (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 in the correct condition and correctly installed.
   (13) Make sure that the sensing elements have no cracks, nicks, sharp edges, bonds, chafing or corrosion.
5. Close-up
Subtask 36-22-17-410-054-A
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 applicable:
     (a) For the APU overheat sensing-elements between FR49 and FR52:
  • Install access panel 151DW.
     (b) For the APU overheat sensing-elements between FR52 and FR55:
  • Install access panel 151EW.
     (c) For the APU overheat sensing-elements between FR55 and FR58:
  • Install access panel 151HW.
     (d) For the APU overheat sensing-elements between FR58 and FR59:
  • Install access panel 151JW.
     (e) For the APU overheat sensing-elements between FR59 and FR62:
  • Install access panel 161AW.
     (f) For the APU overheat sensing-elements between FR62 and FR63:
  • Install access panel 161BW.
     (g) For the APU overheat sensing-elements between FR63 and FR65:
  • Install access panel 161CW.
   (3) For the APU overheat sensing-elements between 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 FR70 and FR77:
  • Close access door 312AR.
   (6) For the APU overheat sensing-elements aft of FR77:
  • Close access door 314AR.
Subtask 36-22-17-865-058-A
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C ALL
49VUAIR BLEED/X FEED/VALVE/BAT2HVD13
49VUAIR BLEED/ENG 2/MONG3HA2D12
49VUAIR BLEED/ENG 1/CTL2HA1D11
122VUAIR BLEED/ENG 1/MONG3HA1Z23
122VUAIR BLEED/ENG 2/CTL2HA2Z22
122VUAIR BLEED/X FEED VALVE/NORM1HVZ20
Subtask 36-22-17-942-056-A
C. Aircraft Maintenance Configuration
   (1) Put the aircraft back to its initial configuration.
   (2) Remove the access platform(s).
   (3) Remove the WARNING NOTICE(S).
[Rev.10 from 2021] 2026.04.01 01:17:25 UTC
"Aviabrain" 2025