Remove, inspect, clean, and reinstall (safety as required) propeller dome
and propeller governor oil screen on propellers which use engine oil.
Carefully inspect main oil screen and sump plugs, when applicable, at 10-
hour operation intervals (or as close thereto as possible) for 100 hours after desludging dilution.
Cold Weather Maintenance. The following paragraphs explain procedures which will
help ensure safe cold weather engine starting.
Draining sumps. When operating aircraft at temperatures below freezing, or when
temperature may drop below the freezing point, open the oil tank sump drains sufficiently to
drain off any accumulation of water.
Oil heating. Oil heating is accomplished by oil immersion heaters. Two different
size heaters that operate on a current supply of 115 volts are available: 250-watt capacity and
750-watt capacity. The aircraft skin near the oil tank filler neck will be stenciled with size of
heater to be used. When not marked, use 250-watt heater in all self-sealing tanks and in metal
tanks with a capacity less than 20 gallons.
· The use of immersion heaters does not eliminate necessity for diluting
· Use only heaters with a perforated shield in self-sealing tanks.
· Do not use a heater of greater wattage than called for in stenciled
statement on aircraft skin.
· Be sure heating element is completely submerged when in use.
· Do not use a heater when free air temperature is above 32°F (0 °C).
Oil dilution. When the viscosity of the oil must be reduced by oil dilution to
facilitate cold weather starting of engines which have not had cyclohexanone added to the oil, or
had periodic oil dilution, the reduced viscosity will also free carbon (sludge) deposits throughout
the engine oil system and create the hazard of plugging drilled oil passageways, blocking oil
cooler tubes, obstructing propeller mechanisms, or otherwise having harmful results. The first oil
dilution of such an engine will be accomplished as follows:
Accomplish this procedure when 50 hours engine time has elapsed since
the preceding dilution.
Run an initial oil dilution procedure for about 2 to 4 minutes.
Stop engine; remove engine oil screen and clean off excess carbon and
sludge by washing screens of filters as outlined in paragraph 3-6d(3).
Drain approximately 1 gallon of oil from Y drain to eliminate sludge which
may have collected in lines in vicinity of Y drain and in hopper sump.
Start engine and run at 1000 to 1200 rpm for 20 minutes to evaporate fuel in oil.
Again dilute engine oil for specified period of time and clean screens.
Handling and Storage of Oils. Covered and outside storage of oil drums is explained in the
Covered Storage. Filled and empty 55-gallon drums may be stored in warehouse or shed
facilities. For covered storage, drums may be stacked horizontally or palletized in the vertical position.
Stacked drums will be placed horizontally (on sides) with closures (bungs and vents) facing outward and
bungs at 3 and 9 o'clock position. Ends of bottom tiers will be braced.
Vertical storage. For convenience of handling and storage, drums may be palletized in the
vertical position. Either 40by 48-inch or 48by 60inch pallets will be satisfactory.
Identification. For proper identification and quality surveillance, product will be stored in
such a manner as to maintain product/grade and batch/lot integrity.
Stability. If drums are multiple-tiered on pallets, a single strap or tape will be applied
around each pallet to enhance stability in handling or while in the stack.