W DOC AIRBUS | AMM A320F

Preservation General Procedure [PW11]


TASK 71-00-00-550-805-A
Preservation General Procedure


CAUTION: DO THE PRESERVATION OF THE ENGINE VERY CAREFULLY WHEN THERE IS A RISK OF LARGE TEMPERATURE CHANGES, MUCH HUMIDITY OR SALT WATER. IN THESE CONDITIONS, DAMAGE TO ENGINE PARTS CAN OCCUR.
ZONE: 400
1. Reason for the Job
Use these preservation guidelines for the protection of out-of-service engines (on-wing or off-wing) or engines to be put into storage. If you follow these guidelines, you will help protect against damage from excessive moisture, debris and other environmental conditions.
2. Job Set-up Information
 A. Work Zones and Access Panels
ZONE/ACCESS
ZONE DESCRIPTION
400
POWER PLANT, NACELLES AND PYLONS
 B. Referenced Information
REFERENCE
DESIGNATION
TASK 71-00-00-550-803-A
Preservation of the Engine (for More than 60 Days)
TASK 71-00-00-550-804-A
Preservation of the Engine (for 60 Days or Less)
TASK 71-00-00-630-802-A
Depreservation of the Engine
TASK 71-00-00-720-816-A
Test No. 17 - Above Idle Test
TASK 72-15-00-200-801-A
Borescope Inspection of the Fan Drive Gearbox (FDG) Assembly
3. Job Set-up
Subtask 71-00-00-010-201-A ** ON A/C NOT FOR ALL
A. Not Applicable
4. Procedure
Subtask 71-00-00-620-078-A ** ON A/C NOT FOR ALL
A. General Environmental Conditions
   (1) Use the preservation guidelines to preserve the engine for 60 days or less (Method I) (Ref. AMM TASK 71-00-00-550-804) or to preserve the engine for more than 60 days (Method II) (Ref. AMM TASK 71-00-00-550-803) to determine what precautions must be done to give sufficient protection to the engine based on your experience with local environmental influences, and past preservation practices. Your engine preservation policy must be a flexible program, implemented to give a maximum of protection to critical engine components (such as gears, bearings and accessory components). Your preservation policy must take into consideration seasonal changes in local conditions (such as temperature and humidity). Use special care in locations where severe temperature changes, severe humidity or salt water could cause a higher risk of damage to engine parts.
Subtask 71-00-00-620-079-A ** ON A/C NOT FOR ALL
B. General Preservation Time
   (1) It is the responsibility of the engine operator to give sufficient protection to the engines that are out of service for extended amounts of time. It is also important that engines are not being preserved, put into storage and forgotten. Regular checks are necessary to be sure that the preservation material and the internal environment is satisfactory. Engine preservation guidelines are for the use of operators to help start and implement a viable engine preservation plan.
   (2) For engines with an expired tag.
CAUTION: BEFORE A BORESCOPE INSPECTION, MAKE SURE THAT:
  • THE ENGINE METAL TEMPERATURE IS NOT LESS THAN THE OUTSIDE AIR TEMPERATURE, AND
  • THE OUTSIDE AIR RELATIVE HUMIDITY IS NOT HIGHER THAN 60 PERCENT. THIS IS TO PROTECT THE COMPONENTS FROM CONDENSATION AND AMBIENT AIR WHICH CAN CAUSE DAMAGE TO THEM.
     (a) Do a borescope inspection of the fan-drive gear system for corrosion (Ref. AMM TASK 72-15-00-200-801).
       1 No corrosion pits are permitted.
     (b) Transport the engine to a test cell or to an aircraft for a test run. Transport the engine by an approved method only to prevent damage to the engine (Ref. AMM TASK 71-00-00-630-802).
Subtask 71-00-00-620-080-A ** ON A/C NOT FOR ALL
C. Determine the preservation method:
   (1) There are two methods of preservation:
NOTE: The engine can remain installed on a parked or stored aircraft for seven days maximum with no preservation.
     (a) Refer to step 4.C.(4) for additional information.
     (b) Preserve the engine for 60 days or less (Method I) (Ref. AMM TASK 71-00-00-550-804).
     (c) Preserve the engine for more than 60 days (Method II) (Ref. AMM TASK 71-00-00-550-803).
   (2) Use the preservation method adapted to the time that the engine will be out of service or in storage.
F Preservation Chart ** ON A/C NOT FOR ALL
   (3) If the length of time the engine will be in storage is not known, use Method II (Ref. AMM TASK 71-00-00-550-803).
   (4) Engines can remain not active on-wing with no preservation in the conditions that follow:
     (a) The engine can be kept inside or outside. If the engine is kept outside, install a tarp or PVC plastic sheet over the inlet cowl, fan exhaust area and the engine exhaust area.
     (b) At an interval of maximum seven days, you must operate the engine on-wing or in a test cell to get the main oil temperature to 211 deg.F (99.44 deg.C) to remove moisture or condensation as follows:
       1 An oil temperature of 211 deg.F (99.44 deg.C) must be achieved when you do the engine run. This can be done at idle or above idle, which depends on the ambient temperature.
       2 The run can be limited to a ten minutes idle run if you use an oil sample to make sure that water content is not more than 1000 ppm.
       3 If you find that the water content is more than 1000 ppm, the oil system must to be flushed or an above idle engine run to reach 211 deg.F (99.44 deg.C) must be done (Ref. AMM TASK 71-00-00-720-816).
     (c) This process can be repeated until it is no longer needed without additional maintenance actions.
CAUTION: AFTER A MAXIMUM OF SEVEN DAYS AND THEN AT SEVEN-DAY INTERVALS (COUNT THE TIME FROM THE FIRST DAY OF NO ENGINE ACTIVITY), OPERATE THE ENGINE TO REMOVE ANY CONDENSATION IN THE OIL. IF YOU DO NOT DO THIS, YOU CAN CAUSE CONTAMINATION OF THE OIL SYSTEM AND CAUSE DAMAGE TO THE PARTS INSIDE THE OIL SYSTEM.
   (5) After seven days (day eight) you must do one of the following:
     (a) Refer to the preservation method chart to determine the correct method of preservation.
F Preservation Chart ** ON A/C NOT FOR ALL
     (b) Return the engine to service.
Subtask 71-00-00-620-081-A ** ON A/C NOT FOR ALL
D. General Requirements For New Delivered Engines
   (1) When a new engine is received from Pratt and Whitney, it has been preserved by Method II. If you do not plan to remove the engine from the shipping bag immediately, follow the applicable storage recommendations.
[Rev.10 from 2021] 2026.04.01 04:22:51 UTC