COLD WEATHER OPS

1
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

2
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

3
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

4
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

5
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

6
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
• Dont run fuel tank nearly dry before switching
  tanks selector valve may have frozen

7
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

8
COLD WEATHER OPS

• Plan descents earlier
• Reduce power gradually
• Maintain power throughout descent
• Keep fuel/air mixture leaned during descent