APU Power Plant Visual Inspection (Honeywell 131-9 (A))

TASK 49-20-00-210-003-A
APU Power Plant Visual Inspection (Honeywell 131-9 (A))

FIN: 4005KM ** ON A/C NOT FOR ALL

1. Reason for the Job
Self explanatory
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	1	ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR
162EW
152FW

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 25-55-11-000-003-A	Removal of the Sidewall Panels in the Aft Cargo Compartment - FR47/FR59
TASK 25-55-11-400-003-A	Installation of the Sidewall Panels in the Aft Cargo Compartment - FR47/FR59
TASK 25-55-12-000-003-A	Removal of the Sidewall Panels in the Aft Cargo Compartment - FR59/FR65
TASK 25-55-12-400-003-A	Installation of the Sidewall Panels in the Aft Cargo Compartment - FR59/FR65
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 49-00-00-710-010-A	Operational Test of the APU
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
TASK 52-30-00-860-006-A	Open the Bulk Cargo-Compartment Door
TASK 52-30-00-860-008-A	Close the Bulk Cargo-Compartment Door
TASK 52-41-00-010-001-A	Open the APU Doors for Access
TASK 52-41-00-410-001-A	Close the APU Doors after Access

3. Job Set-up
Subtask 49-20-00-860-090-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) On the panel 25VU, make sure that the APU MASTER SW pushbutton switch is off.
(3) Put a WARNING NOTICE(S) in the cockpit to tell persons not to start the APU.
(4) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).

Subtask 49-20-00-865-094-A ** ON A/C NOT FOR ALL

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-20-00-010-070-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position below the APU access doors 315AL and 316AR.
(2) Open the access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Set the LIGHT control switch 11LJ to the on position.

Subtask 49-20-00-010-072-B ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the BULK cargo-compartment door 827 (Ref. AMM TASK 52-30-00-860-006).
(2) Put the ACCESS PLATFORM 2M (6 FT) at the BULK cargo-compartment door 827.
(3) Remove the access panel 162EW (Ref. AMM TASK 25-55-12-000-003).

Subtask 49-20-00-010-072-C ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the AFT cargo-compartment door 826 (Ref. AMM TASK 52-30-00-860-001).
(2) Put the ACCESS PLATFORM 2M (6 FT) below the AFT cargo-compartment door 826.
(3) Remove the access panel 152FW (Ref. AMM TASK 25-55-11-000-003).

4. Procedure
Subtask 49-20-00-210-057-A ** ON A/C NOT FOR ALL

A. Visual Inspection
(1) If you find damage during the visual inspection, do the applicable procedures to make each component serviceable.
(2) Examine the following APU power plant components for loose connectors, worn parts, cracks, distortion and corrosion:
(a) The electrical connectors of the APU harness.
(b) The connections, clamps and brackets of the APU harness.
(c) The gearbox assembly.
(3) Examine the APU oil tubes and fuel tubes for leaks. No leaks are permitted.
(4) Examine the following systems for leaks and damage:
(a) The APU fuel and control system.

the fuel control unit,
the fuel filter,
the fuel flow divider,
the primary fuel manifold,
the secondary fuel manifold,
the combuster drain valve.

(b) The APU ignition and starting system:

the starter motor,
the ignition unit,
the ignitor plugs,
the ignitor cables.

the inlet plenum,
the inlet guide vane actuator,
the air inlet pressure / temperature sensor,
the bleed control valve,
the surge control valve,
the compressor discharge pressure sensor,
the bleed air duct,
load compressor scroll,
the T-duct,
the Duct-Surge.

(d) The APU accessory cooling system:

the cooling fan,
the fan outlet duct assembly,
the fan inlet duct assembly,
the oil cooler exhaust duct.

(e) The APU controls system:

the electronic control box,
the electronic control box mounting bracket.

(f) The APU indicating system:

the speed sensor,
the thermocouple,
the data memory module.

(g) The APU exhaust system:

the exhaust muffler,
the sealing ring.

(h) The APU oil system:

the sight gauge,
the lube module,
the oil filters,
the magnetic chip detector and drain plug,
the de-oiling solenoid valve,
the oil level sensor,
the oil temperature sensor,
the low oil pressure switch,
the oil cooler,
the oil heater (if applicable).

Subtask 49-20-00-710-068-A ** ON A/C NOT FOR ALL

B. Inspection/Test

CAUTION: MAKE SURE THAT THE FUEL-FEED SYSTEM DOES NOT HAVE ANY LEAKS. LEAKS IN THE FUEL-FEED SYSTEM CAN CAUSE A FIRE.

CAUTION: MAKE SURE THAT YOU HAVE THE CORRECT FIRE FIGHTING EQUIPMENT AVAILABLE. THE APU FIRE EXTINGUISHING SYSTEM IS NOT SUFFICIENT TO EXTINGUISH A FIRE IF THE ACCESS DOORS 315AL AND 316AR ARE OPEN/ REMOVED. KEEP OPERATION OF THE APU TO A MINIMUM WHEN THE ACCESS DOORS ARE OPEN/REMOVED.

(1) Do the operational test of the APU (Ref. AMM TASK 49-00-00-710-010).
(a) Operate the APU for min. five minutes and examine the APU for fuel, oil and air leaks.

NOTE: Leaks are not permitted.

5. Close-up
Subtask 49-20-00-410-074-B ** ON A/C NOT FOR ALL

A. Close Access
(1) Set the APU MASTER SW pushbutton switch to the OFF position.
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Install the access panel 162EW (Ref. AMM TASK 25-55-12-400-003).
(4) Close the BULK cargo-compartment door 827 (Ref. AMM TASK 52-30-00-860-008)
(5) Remove the access platform(s).

Subtask 49-20-00-410-074-C ** ON A/C NOT FOR ALL

A. Close Access
(1) Set the APU MASTER SW pushbutton switch to the OFF position.
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Install the access panel 152FW (Ref. AMM TASK 25-55-11-400-003).
(4) Remove the access platform(s).
(5) Close the AFT cargo-compartment door 826 (Ref. AMM TASK 52-30-00-860-002).

Subtask 49-20-00-410-072-A ** ON A/C NOT FOR ALL

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Set the LIGHT control switch 11LJ to the off position.
(3) Close the APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
1KD, 2KD.
(5) Remove the access platform(s).
(6) Remove the WARNING NOTICE(S).

Subtask 49-20-00-860-091-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 01:28:42 UTC