Procedure to Dry Out the High Pressure Turbine (HPT) after Oil Contamination [IAE]

TASK 71-00-00-700-013-A
Procedure to Dry Out the High Pressure Turbine (HPT) after Oil Contamination

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 400

1. Reason for the Job
To remove oil that has leaked from the No. 4 bearing compartment and collected in the diffuser case and/or the high pressure turbine, if there is an oil leak. This procedure uses engine operation at MIN IDLE to flush oil out of the diffuser module and/or the high pressure turbine. The oil goes out of the diffuser module through the No. 4 bearing oil weep tube into the turbine exhaust case port and oil goes out of the HPT through the cooling holes that lead to the gas path.
2. Job Set-up Information
A. Consumable Materials

REFERENCE	DESIGNATION
(Material No.V01-002)	cleaning fluid

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL, 452AR, 461AL, 462AR
FOR [1000EM2] (ENGINE-2)
437AL, 438AR, 447AL, 448AR, 461AL, 462AR

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 31-60-00-860-001-A	EIS Start Procedure
TASK 31-60-00-860-002-A	EIS Stop Procedure
TASK 71-00-00-710-018-A	Discontinued Start, Restart and Shutdown Procedures
TASK 71-00-00-710-043-A	Normal Engine Automatic-Start Procedure
TASK 71-00-00-710-047-A	Normal Engine Manual-Start Procedure
TASK 71-00-00-860-010-B	Engine Operation Limits, Guidelines and Special Procedures
TASK 71-00-00-860-011-C	Table of Idle Indications
TASK 71-00-00-860-011-C-01	Table of Idle Indications
TASK 71-00-00-860-012-A	Engine Safety Precautions
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 72-50-00-200-010-A	Inspection of the Turbine Exhaust Case
TASK 78-30-00-040-012-A	Deactivation of the Thrust Reverser Hydraulic Control Unit (HCU) for Ground Maintenance
TASK 78-30-00-040-013-A	Deactivation of the Thrust Reverser System for Flight
TASK 78-30-00-440-012-A	Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after Ground Maintenance
TASK 78-30-00-440-013-A	Activation of the Thrust Reverser System for Flight
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
No. 4 Bearing Compartment Scavenge Oil System
Flowchart to Find if Dry Out Procedure is Necessary

3. Job Set-up
Subtask 71-00-00-010-157-A ** ON A/C NOT FOR ALL

A. Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-010):
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
437AL 438AR.

Subtask 71-00-00-040-092-A ** ON A/C NOT FOR ALL

B. Deactivate the thrust reverser.

WARNING: 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).
(2) Deactivate the thrust reverser system (Ref. AMM TASK 78-30-00-040-013).

Subtask 71-00-00-010-158-A ** ON A/C NOT FOR ALL

C. 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 71-00-00-861-094-A ** ON A/C NOT FOR ALL

D. Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).

Subtask 71-00-00-860-147-A ** ON A/C NOT FOR ALL

E. Get Access
(1) Do the EIS start procedure (Ref. AMM TASK 31-60-00-860-001).

Subtask 71-00-00-860-149-A ** ON A/C NOT FOR ALL

F. Find out if this dry out procedure of the HPT is necessary:
(1) If you do more than one maintenance task that needs a HPT dry-out, then the HPT dry-out is only needed once.
(2) If you do consecutive engine motoring, then you must do the HPT dry-out after the last engine motor.
(3) If you do consecutive above idle engine operations, then you must do the HPT dry-out before the first above idle engine operation.
(4) If there is oil leakage at the No.4 bearing weep tube exit, then this procedure is necessary.
(5) If there is no leakage at the No.4 bearing weep tube exit and the oil in the turbine package 2 configuration has been installed per SBE 72-0541, then this procedure is not necessary.
(6) The engine must look like in the figure:

No. 4 Bearing Compartment Scavenge Oil System ** ON A/C NOT FOR ALL

Subtask 71-00-00-210-093-A ** ON A/C NOT FOR ALL

G. Inspect the turbine exhaust case for oil leaks from the No. 4 bearing weep tube exit (Ref. AMM TASK 72-50-00-200-010). See the flowchart

Flowchart to Find if Dry Out Procedure is Necessary ** ON A/C NOT FOR ALL

to find if the procedure is necessary. If the procedure is not necessary, no further action is necessary. If the procedure is necessary, continue with the steps that follow.

4. Procedure
Subtask 71-00-00-110-063-A ** ON A/C NOT FOR ALL

A. Clean the parts.

WARNING: DO NOT GET CLEANING FLUID ON YOUR SKIN OR IN YOUR EYES. PUT ON PROTECTIVE CLOTHING, GOGGLES, AND A FACE MASK. USE THE FLUID IN AN AREA WITH GOOD AIR FLOW. DO NOT BREATHE THE GAS. IF YOU GET THE CLEANING FLUID ON YOUR SKIN OR IN YOUR EYES, FLUSH IT AWAY WITH WATER. GET MEDICAL AID IF YOUR SKIN OR EYES BECOME IRRITATED.

(1) Use a clean, lint-free cloth, made moist with cleaning fluid (Material No.V01-002) , to clean the following parts:
(a) The internal surfaces of the turbine exhaust case
(b) The external surfaces of the turbine exhaust case
(c) The tubes of the turbine exhaust case.
(2) Make sure that the parts are free from soot, coke, and wet oil.
(3) Dry the parts with a clean, lint-free cloth.

Subtask 71-00-00-710-200-A ** ON A/C NOT FOR ALL

CAUTION: DO NOT OPERATE THE ENGINE ABOVE IDLE DURING THIS PROCEDURE. IF YOU DO, THE OIL THAT IS IN THE HIGH PRESSURE TURBINE CAN IGNITE. THIS CAN CAUSE ENGINE COMPONENT DAMAGE.

B. Operate the engine at MIN IDLE for 15 minutes.

NOTE: For general information, refer to Engine Safety Precautions (Ref. AMM TASK 71-00-00-860-012) and Engine Operation Limits, Guidelines, and Special Procedures (Ref. AMM TASK 71-00-00-860-010). Engine operation at MIN IDLE during this procedure will push the oil that collected in the HPT to the turbine exhaust case. Do the procedure as many times as necessary to remove all the oil from the HPT.

(1) Operate the engine at MIN IDLE only for this procedure.
(2) Start the engine with either the Normal Engine Automatic Start Procedure (Ref. AMM TASK 71-00-00-710-043) or Normal Engine Manual Start Procedure (Ref. AMM TASK 71-00-00-710-047).
(3) Make sure the indications are in the limits of operation (Ref. AMM TASK 71-00-00-860-011).
(4) Operate the engine at MIN IDLE for a minimum of 15 minutes.
(5) Do a shutdown with the Discontinued Start and Shutdown Procedure (Ref. AMM TASK 71-00-00-710-018).

Subtask 71-00-00-220-050-A ** ON A/C NOT FOR ALL

C. Inspect the turbine exhaust case for oil

NOTE: Follow engine safety guidelines while you inspect the turbine exhaust case (Ref. AMM TASK 71-00-00-860-010).

(1) Visually inspect the turbine exhaust case for oil that went out of the No. 4 bearing weep tube port (Ref. AMM TASK 72-50-00-200-010).
(2) If you find oil, do the steps that follow:
(a) Clean the oil from the turbine exhaust case.
(b) Do the procedure given in paragraph B again.
(3) If oil continues to collect in the turbine exhaust case after five MIN IDLE operations, remove the engine from service.
(4) If you do not find oil, return the engine to service.

5. Close-up
Subtask 71-00-00-860-148-A ** ON A/C NOT FOR ALL

A. Do the EIS stop procedure
(Ref. AMM TASK 31-60-00-860-002).

Subtask 71-00-00-862-087-A ** ON A/C NOT FOR ALL

B. De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

Subtask 71-00-00-410-144-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser halves (Ref. AMM TASK 78-32-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM1] (ENGINE-1)
461AL 462AR.

Subtask 71-00-00-440-088-A ** ON A/C NOT FOR ALL

D. Activate the thrust reverser system and HCU (Ref. AMM TASK 78-30-00-440-013) and (Ref. AMM TASK 78-30-00-440-012).

Subtask 71-00-00-410-145-A ** ON A/C NOT FOR ALL

E. Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-010):
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR.

[Rev.10 from 2021] 2026.04.01 02:28:25 UTC