During a climb, which action helps to cool an overheating engine?

• A. Increase rate of climb and reduce airspeed.
• B. Maintain current flight path.
• C. Reduce engine power to idle.
• D. Reduce rate of climb and increase airspeed.

Answer: (D)

Engine cooling in flight mainly comes from ram air flowing through the cooling system; the more air you have moving over the engine, the more heat is carried away. In a climb, airspeed is usually lower, so cooling is less effective and the engine tends to heat up. The best way to boost cooling is to reduce the rate of climb and allow the airspeed to rise, which increases the amount of cooling air flowing past the engine. This extra airflow helps temperatures drop more quickly. Increasing the climb rate would keep airspeed down and worsen cooling, while maintaining the same flight path won’t change cooling. Reducing power to idle lowers engine heat but also reduces thrust and isn’t as effective at increasing cooling air flow as simply gaining speed while lowering the climb.