15.22 Storage & Preservation Flashcards
What is the purpose of preserving engines that are not intended to be operated for any specific length of time?
To protect against corrosion by moisture, rain, snow, and the entry of foreign object matter such as dust, birds, and insects.
Where can the preservation and de-preservation procedures for installed engines be found?
Chapter 71 (Power Plant) of the Aircraft Maintenance Manual (AMM).
Where can the preservation procedures for uninstalled engines be found?
Chapter 72 of the AMM.
What defines short-term storage for installed engines?
Up to seven days.
What defines medium-term storage for installed engines?
Over seven days but not exceeding thirty days.
What defines long-term storage for installed engines in temperate and dry climates?
Over thirty days but not exceeding six months.
What defines long-term storage for installed engines in humid, tropical climates?
Over thirty days but not exceeding three months.
What should be done during short-term storage for installed and serviceable engines?
Start and run the engine at ground idle for three minutes and install engine inlet and exhaust covers.
What is required if an engine is expected to be out of service for more than seven days?
Carry out a medium-term (thirty-day) preservation procedure.
What should be done if an engine is shut down during flight?
Dry out the engine internally before fitting the engine inlet and exhaust covers.
What should be done during medium-term storage for installed and serviceable engines?
Start and run the engine at ground idle for fifteen minutes and inhibit the fuel system as necessary.
What indicates low humidity in desiccant crystals during medium-term storage?
The color blue.
What indicates high humidity in desiccant crystals during medium-term storage?
The colors lilac or pink.
What must be installed over the whole power plant during medium-term storage?
A waterproof cover.
What should be done for long-term storage of installed and serviceable engines?
Carry out the thirty-day medium-term preservation procedure first and grease all control rods and fittings.
What is the procedure for long-term storage of installed and unserviceable engines?
Follow the same procedure as for serviceable engines, including the drying-out procedure if shut down in flight.
What must be done if the storage period exceeds six months?
Renew the preservation procedure or remove the engine and preserve it in a Moisture Vapour Proof (MVP) bag.
What is the first step for preservation of uninstalled engines if out of service for less than seven days?
Fit the engine inlet and exhaust covers.
What should be done if the expected storage period exceeds thirty days for an uninstalled engine?
Place the engine in an MVP bag.
Why is engine fuel system inhibiting necessary?
To prevent corrosion caused by water absorbed in aviation fuel.
What methods can be used for filling the engine fuel system with inhibiting oil?
- Motoring method
- Pressure rig method
- Gravity method
What is the humidity indicator’s purpose when fitting an engine into an MVP bag?
To monitor moisture levels inside the bag.
How often should the humidity indicator be checked after sealing the MVP bag?
Twenty-four hours after desiccation, one week after, fortnightly if in the open, and monthly if undercover.
What should be done if the humidity indicator turns lilac or pink?
Inspect the bag for damage, replace desiccant and indicator, and investigate the cause.
What procedures should be followed for de-preservation of installed engines?
- Remove all engine covers, blanks, barrier films, and desiccants
- Clean the engine and remove protective grease
- Drain and clean the oil system
- Drain inhibiting oil from the fuel system and prime the fuel system with clean fuel
What is the maximum storage duration for engines in an MVP bag?
Up to three years.
What should be done if an MVP bag is opened during storage?
Carry out the full re-desiccation procedure before resealing the bag.
True or False: The preservation procedure can be renewed for additional thirty-day periods.
True
What is the first step in preparing the oil system?
Drain the oil system of storage oil
This involves removing any oil that has been stored in the system to ensure cleanliness.
What should be done after draining the storage oil?
Clean the oil filters, fill the oil system with the normal lubricating oil, and prime the oil system
Proper maintenance of oil filters is crucial for optimal engine performance.
What is the procedure for the engine fuel system?
Drain the inhibiting oil from the engine fuel system
Inhibiting oil must be removed to avoid contamination of the fuel system.
What should be replaced after draining the inhibiting oil?
Replace the low-pressure fuel filter
This ensures that the fuel system operates efficiently and free of blockages.
What tools should be fitted to the high-pressure fuel pump and the fuel control unit?
Fit the bleed tools
Bleed tools are essential for removing air from the fuel system.
What should be done with the low-pressure fuel cock?
Open the low-pressure fuel cock
This allows fuel to flow through the system for bleeding.
How should the engine fuel system be bled and primed?
Using the aircraft fuel booster pumps until clean fuel is passed from the bleed points
This step ensures that the fuel system is free of air and impurities.
What is the final step after preparing the oil and fuel systems?
Start the engine and carry out a performance check of the engine and its systems
Checking performance is critical to ensure everything is functioning correctly.
