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