M15.22 Engine storage and preservation Flashcards
What periods of time are there for the preservation of installed engines?
Short term storage
* Up to seven days.
* Over seven days but not exceeding thirty days
Long term storage
* Over thirty days but not exceeding six months in temperate and dry climates.
* Over thirty days but not exceeding three months in humid tropical climates.
What are the requirements for storing installed and serviceable engines up to 7 days?
Start and run the engine for three minutes
Exercise the pitch mechanism if its a turbo prop
Install engine blanks
What are the requirements for storing installed and unserviceable engines up to 7 days?
If an engine is shut down normally after flight, fit the engine inlet and exhaust covers to prevent wind-milling and foreign object ingestion.
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f an engine is shut down during flight, the engine must be dried out internally before fitting the engine inlet and exhaust covers. This can be done with the aid of a warm air trolley.
If the engine is expected to be out of service for periods in excess of seven days, either carry out a thirty day or a six month storage procedure as required.
What are the requirements for storing installed and serviceable engines up to 30 days?
Start and run the engine for 15 mins.
Exercise the pitch mechanism if its a turbo prop.
If required, inhibit the fuel system, ensuring the shut off valves are closed.
The lubrication fluid should be drained, filters cleaned and refitted, then service the oil to normal level with clean oil or inhibiting oil or a mix of both.
Clean the exterior of the engine.
Depending on the instructions in the relevant procedure, one or more of the following may be required.
* The correct weight of bagged silica gel crystal desiccant should be placed in the engine inlet and exhaust areas. The desiccant crystal color should be blue (indicating low humidity).
- Some procedures may call for Vapor Phase Inhibitor Paper (VPI) to be placed within the engine inlet and exhaust. Other procedures may call for the engine inlet and exhaust openings to be sealed with a vapor barrier film. There may also be a requirement to place bagged desiccant either side
of the engine. Vapor barrier film may have to be taped over the compressor bleed valve outlet grille(s). - Install the engine inlet and exhaust covers.
- Install a waterproof cover over the whole of the power plant
When does the 30 day preservation period begin?
From the time of the last engine run
What are the requirements for storing installed and un-serviceable engines up to 30 days?
Up to thirty days (installed and unserviceable)
If the engine was shut down normally after flight, proceed as for a serviceable engine disregarding the engine ground run.
If the engine was shut down in flight, carry out an engine drying out
procedure. This procedure is laid down in the maintenance manual and would normally involve the use of a warm air trolley passing warm air into the exhaust duct until the front stage LP compressor blades become warm. Preservation is the same as for a serviceable engine. If a propeller is fitted the pitch change mechanism can be exercised by feathering and un-feathering using the electrical feathering motor.
For an installed and un-serviceable engine, when does the 30 day preservation period begin?
From the completion of the drying out procedure
What are the requirements of long term storage up to 6 months for installed and servicable engines?
The thirty day short term preservation procedure must be carried out first. All engine control rods and fittings must be greased.
All vents and apertures must be blanked off with vapour barrier film or greaseproof paper. PVC tape must not be used on its own to blank off or bridge apertures as it can collect grit and cause corrosion. All rubber parts and electrical cables must be protected with greaseproof paper and the fire extinguisher distribution spray rings covered before spraying a thin coat of preservative over the engine casings forward of the exhaust. Install a waterproof cover over the whole power plant and attach an identification label showing the date of the preservation procedure. If the
propeller cannot be exercised, the pitch change mechanism should be filled with an approved inhibiting oil.
When should an unserviceable engine be removed and fitted into the MVP bag?
If it remains unserviceable beyond six months
What should happen with a turbo prop engine when put into long term storage?
The prop should be removed and stored separately
How is an uninstalled engine stored when not exceeding 7 days?
If the engine is to be out of use for periods not exceeding seven days from its last operation then only the engine inlet and exhaust covers need be fitted.
If the engine is a turbo-prop, the propeller will have already been removed and the propeller shaft oil-ways blanked off.
If an uninstalled engine is being stored for more than 7 days but less than 30 what should happen?
If the storage period is expected to exceed seven days but not exceed 30 days from the last engine operation then the fuel system should be inhibited. The storage requirements will be similar to that for an installed unserviceable engine.
If the storage period exceeds 30 days what should happen?
The engine should be put in an MVP bag
When inhibiting an engine, what should be done?
Drain an inhibit the fuel system,
Methods of filling the fuel system with inhibiting oil are?
Motoring
Pressure rig
Gravity method
