ENGINE COOLING SYSTEMS
1. What is meant by pressure cooling of an aircraft engine? - correct answer-Air cooling in
which air is forced to flow through baffles and cylinder fins by a pressure differential across
the engine.
2. What is the purpose of an augmentor tube in the cooling system of an aircraft reciprocating
engine? - correct answer-The augmentor tube uses the velocity of the exhaust gases to produce
a low pressure on one side of the engine that helps pull cooling air through it.
3. Where is the highest temperature located in a turbine engine? - correct answer-At the
inlet to the high-pressure turbine.
4. How are the turbine inlet guide vanes and the first-stage turbine blades in some turbine
engines cooled? - correct answer-High-pressure compressor bleed air flows through the hollow
guide vanes and hollow turbine blades.
5. Which side of an air-cooled engine cylinder has the greatest amount of cooling fins? - correct
answer- The side of the cylinder in which the exhaust valve is located.
6. What should be done to repair a bent cooling fin in a cast aluminum cylinder head? - correct
answer-It is normally best to leave a bent cast fin alone if it does not restrict the flow of air.
Cast fins are brittle and could break off.
7. What is used in a helicopter to increase the amount of cooling air that flows over
the engine cylinders? - correct answer-A belt-driven fan.
8. What should be the position of the cowl flaps on a reciprocating engine when it is run on the
ground?
- correct answer-They should be wide open when operating the engine on the ground.
9. What is the function of the majority of the air that passes through a turbine engine? - correct
answer- Most of the air is used for cooling.
1. What is meant by pressure cooling of an aircraft engine? - correct answer-Air cooling in
which air is forced to flow through baffles and cylinder fins by a pressure differential across
the engine.
2. What is the purpose of an augmentor tube in the cooling system of an aircraft reciprocating
engine? - correct answer-The augmentor tube uses the velocity of the exhaust gases to produce
a low pressure on one side of the engine that helps pull cooling air through it.
3. Where is the highest temperature located in a turbine engine? - correct answer-At the
inlet to the high-pressure turbine.
4. How are the turbine inlet guide vanes and the first-stage turbine blades in some turbine
engines cooled? - correct answer-High-pressure compressor bleed air flows through the hollow
guide vanes and hollow turbine blades.
5. Which side of an air-cooled engine cylinder has the greatest amount of cooling fins? - correct
answer- The side of the cylinder in which the exhaust valve is located.
6. What should be done to repair a bent cooling fin in a cast aluminum cylinder head? - correct
answer-It is normally best to leave a bent cast fin alone if it does not restrict the flow of air.
Cast fins are brittle and could break off.
7. What is used in a helicopter to increase the amount of cooling air that flows over
the engine cylinders? - correct answer-A belt-driven fan.
8. What should be the position of the cowl flaps on a reciprocating engine when it is run on the
ground?
- correct answer-They should be wide open when operating the engine on the ground.
9. What is the function of the majority of the air that passes through a turbine engine? - correct
answer- Most of the air is used for cooling.
