COLD WEATHER OPS

• When temp. less than 25 deg. F, preheat should be applied to engine

• Insufficient heat causes hard starting, abnormal wear to internal engine parts, reduced engine performance, and shortened TBO

• Plugs can ice-up during start attempt due to condensation and freezing of water vapor

COLD WEATHER OPS• Exercise special caution regarding any

possible water contamination of fuel - water can freeze in fuel line; drain tanks and sump

• Check engine breather tube! Moisture frozen in end of breather tube can lead to loss of engine oil

• Check fuel selector valve for freedom of movement; statistics document cases of frozen selector

COLD WEATHER OPS• Freezing temps can destroy aircraft battery

• Battery with full charge survives, nicely; discharged battery will freeze and requires replacement

• If battery is run down in attempt to start, do not leave it! Get it charged immediately

• Always double check that master switch is off when securing, to prevent discharge and freezing of battery

COLD WEATHER OPS

• Amount of priming must be increased as air becomes colder and more dense

• However, do not overprime! This can lead to engine fire

• Throttle position should be slightly closer to idle position, on start-up, because of colder, more dense air

COLD WEATHER OPS

• General rule for engine starters:

after three, 10-second periods of operation, with a pause between each, a five minute cooling period is required

• Failure to observe this can lead to starter overheating and damage/failure

COLD WEATHER OPS• After start, do not idle below 1000 RPM; cold

temperatures increase probability of lead fouling of plugs

• During flight, exercise constant speed props every 30 minutes to prevent congealing of oil in prop dome

• Don’t run fuel tank nearly dry before switching tanks; selector valve may have frozen

COLD WEATHER OPS

• Allow extra time for oil to warm up after start-up; in T-34, because of 12 quart sump, 15 minutes at idle may be required to bring oil to minimum operating temp

• Avoid power-off descents - engine should not be “shock cooled”; cylinder head temp change should not exceed 50 degrees F per minute

COLD WEATHER OPS

• Plan descents earlier

• Reduce power gradually

• Maintain power throughout descent

• Keep fuel/air mixture leaned during descent