Procedure After Volcanic Ash Environment Operation (APS3200)

TASK 49-00-00-200-807-A
Procedure After Volcanic Ash Environment Operation (APS3200)

1. Reason for the Job

NOTE: This procedure is in agreement with EASA Safety Information Bulletin 2010-17 and ICAO Volcanic Ash Contingency Plan EUR Doc 019. This procedure applicable if APU is operated on Low or Medium Ash Concentration Areas accordingto referred documents. If APU is operated on High Ash Concentration Areas, removal of the APU and shop investigation is recommended.

NOTE: APU operations in or through known volcanic ash laden environments shouldbe avoided due to the numerous potential for maintenance issues. The long term effects of exposure to the volcanic ash are not certain and may manifest themselves hundreds of hours later. If ash laden environments are encountered contact Pratt & Whitney Global Operations Centre (GOC) at +1 860-565-0140 by phone, +1 860-622-3113 by fax or mail to: HELP24@pw.utc.com

NOTE: If the volcanic ash contamination occurred when the aircraft was on ground with applicable protection by covers and blankets (Ref. AMM 10-11-00), and if there is no ash behind the covers, the following inspections specified are not necessary

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE
No specific	AR	BLOWING EQUIPMENT - DRY AIR
No specific	1	PROBE - NON METALLIC, FLEXIBLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	VACUUM CLEANER
No specific	1	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

D. 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 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
TASK 26-22-00-210-001-A	Detailed Inspection of Distribution Piping
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 31-36-00-740-010-A	Printout of the Stored Reports
TASK 49-00-00-710-008-A	Operational Test of the APU
TASK 49-32-41-920-002-A	Replacement of the Fuel Filter (APS 3200)
TASK 49-52-53-000-001-A	Removal of the Permanent Magnet Generator (PMG) and Cooling Fan Assembly (APS 3200)
TASK 49-52-53-400-001-A	Installation of the Permanent Magnet Generator (PMG) and Cooling Fan Assembly (APS 3200)
TASK 49-81-41-000-002-A	Removal of the Exhaust Muffler (APS 3200)
TASK 49-81-41-400-002-A	Installation of the Exhaust Muffler (APS 3200)
TASK 49-91-00-210-002-A	Visual Inspection of the Lube Pump Filter and Generator-Scavenge Filter Differential-Pressure Indicator Position (APS 3200)
TASK 49-91-44-000-003-A	Removal of the Oil Cooler (APS 3200)
TASK 49-91-44-400-003-A	Installation of the Oil Cooler (APS 3200)
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
TASK 52-41-18-400-001-A	Installation of the APU Exhaust Access-Fairing

3. Job Set-up
Subtask 49-00-00-860-188-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, press the APU MASTER SW pushbutton switch then make sure that the APU air intake flap has moved to the fully open position.
(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 49-00-00-865-185-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 49-00-00-010-099-A ** ON A/C NOT FOR ALL

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

4. Procedure
Subtask 49-00-00-280-050-A ** ON A/C NOT FOR ALL

A. Procedure After Volcanic Ash Environment Operation

CAUTION: IF THERE IS DRY ASH, DO NOT USE FLUIDS TO REMOVE THE ASH. IF THERE IS A LAYER OF ASH ON THE AIRCRAFT SURFACES, REMOVE THE ASH WITH A VACUUM CLEANER (OR, IF YOU CANNOT USE A VACUUM CLEANER, USE AN AIR BLOWER, A SOFT CLOTH OR A HAND BRUSH). FLUIDS CAN MIX WITH THE ASH AND MAKE A PASTE THAT CAN CAUSE EROSION/ABRASION. THIS PASTE CAN GO INTO AREAS THAT ARE NOT EASY TO CLEAN.

(1) Inspect APU Air Intake System for ash contamination. If you find contamination:
(a) Clean the Air Intake System with a dry Textile-Lint free Cotton - (Material No.14SBA1) , VACUUM CLEANER and BLOWING EQUIPMENT - DRY AIR to remove any ash that could be ingested.
(2) Inspect the Exhaust System. If you find contamination:
(a) Remove the exhaust muffler (Ref. AMM TASK 49-81-41-000-002).
(b) Clean the Exhaust Muffler with a dry Textile-Lint free Cotton - (Material No.14SBA1) , VACUUM CLEANER and BLOWING EQUIPMENT - DRY AIR to remove any ash that could be ingested.
(c) Inspect the Exhaust Muffler Drain System.
(d) If you find blockage into the exhaust drain line, use a PROBE - NON METALLIC, FLEXIBLE to make sure that the drain pipe is not blocked. If the drain pipe is blocked, remove the blockage without neither water nor any water based agent. BLOWING EQUIPMENT - DRY AIR is recommended to remove possible blockages.
(e) Install the Exhaust Muffler (Ref. AMM TASK 49-81-41-400-002)
(3) Examine the Drain Mast for contamination:
(a) Examine the Drain Mast and all the drain lines.
(b) If you find blockage in the Drain Line, use a PROBE - NON METALLIC, FLEXIBLE to make sure that the drain pipe is not blocked.
(c) It the drain pipe is blocked, remove the blockage without water or any water based agent. BLOWING EQUIPMENT - DRY AIR is recommended to remove possible blockages.
(4) Do a general visual inspection of the APU ventilation system and the APU Compartment for contamination. If you find contamination:
(a) Remove all volcanic ashes from visible and easy access areas or the APU compartment and the APU ventilation system. Use a clean Textile-Lint free Cotton - (Material No.14SBA1) , VACUUM CLEANER and BLOWING EQUIPMENT - DRY AIR to remove any ash that could be ingested in the APU compartment.
(5) Examine if there is contamination in the Oil Cooler:
(a) Print the APU MES/IDLE Report <13> (Ref. AMM TASK 31-36-00-740-010) and record the Oil Sump Temperature (OTA) and Load Compressor Inlet Temperature (LCIT) parameters shown in APU MES/IDLE Report <13>.
1 These two parameters may be used to compute an Oil Temperature (OT) taking into account the environmental effect of temperature: OT=OTA-LCIT. Limit values for OT are:
a For LCIT<20deg.C (68deg.F); OT: 115deg.C (239deg.F)
b For 20deg.C (68deg.F) < LCIT < 35deg.C (95deg.F); OT:95deg.C (203deg.F)
c For LCIT>35deg.C (95deg.F); OT: 90deg.C (194deg.F)
2 If OT is less than limit values, continue operation APU normally.
3 If OT get limit value:
a Remove Oil Cooler (Ref. AMM TASK 49-91-44-000-003)
b Clean the Oil Cooler using a clean Textile-Lint free Cotton - (Material No.14SBA1) , VACUUM CLEANER and BLOWING EQUIPMENT - DRY AIR to remove all the ashes and dirt found.
c Remove the PMG and the Cooling Fan Assembly (Ref. AMM TASK 49-52-53-000-001)
d Clean the Fan Assembly and the ducts using a clean Textile-Lint free Cotton - (Material No.14SBA1) , VACUUM CLEANER and BLOWING EQUIPMENT - DRY AIR to remove all the ashes and dirt found.
e Install the PMG and Cooling Fan Assembly (Ref. AMM TASK 49-52-53-400-001)
f Install the Oil Cooler (Ref. AMM TASK 49-91-44-400-003)
(6) Visual Inspection of the Lube Pump Filter and Generator-Scavenge Filter Differential-Pressure Indicator Position (Ref. AMM TASK 49-91-00-210-002)

NOTE: If A/C operates regularly in ash laden environments a change of oil filters and a change of oil are recommended every 100 hours of operation.

(7) Examine the fire extinguisher outlets for contamination (Ref. AMM TASK 26-22-00-210-001)
(8) If A/C fuel system maintenance is required because of ash contamination then replace the APU fuel filters. (Ref. AMM TASK 49-32-41-920-002)
(9) Do an operational test (Ref. AMM TASK 49-00-00-710-008) and if the test result is not satisfactory, shutdown the APU and do the troubleshooting provided for the fault/s detected during the operational test.
(10) Record operation of APU in ash environment in APU logbook.

5. Close-up
Subtask 49-00-00-410-093-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 APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-410-001).
(3) Install the APU exhaust access-fairing 317AL (Ref. AMM TASK 52-41-18-400-001).
(4) Set the LIGHT SW 11LJ to the OFF position.
(5) Remove the access platform(s).

Subtask 49-00-00-865-186-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close 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 49-00-00-860-189-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) Put the related hydraulic system in the pressurized configuration (Ref. AMM TASK 29-00-00-864-001).
(2) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 01:26:10 UTC