Lubrication

Question 1

What are the six functions of the oil in an aircraft engine? (AM.III.G.K2)

Answer 1

1. Reduces friction
2. Seals & cushions
3. Removes heat
4. Cleans inside the engine
5. Protects against corrosion
6. Performs hydraulic action

Question 2

What is the purpose of an air-oil separator, or deaerator, in an engine oil tank? (AM.III.G.K2)

Answer 2

In normal operation, the oil picks up a quantity of air and it is swirled as it enters the deaerator. The swirling acting releases the air from the oil, and the air is used to pressurize the oil tank.

Question 3

How is oil pressure regulated in an aircraft engine? (AM.III.G.K2)

Answer 3

A pressure relief valve senses the desired pressure and sends excess oil back into the engine sump.

Question 4

What is the purpose of the restricted orifice in the line between the oil pressure gauge and the engine? (AM.III.G.K2).

Answer 4

The restricted fitting helps dampen any pulsations in the oil pressure caused by the pump.

Question 5

What is a hot tank lubrication system for a turbojet engine? (AM.III.G.K2)

Answer 5

A lubrication system in which the oil cooler is in the pressure subsystem and the scavenged oil is not cooled before it returns to the tank.

Question 6

What is a cold tank lubrication system for a turbojet engine? (AM.III.G.K2)

Answer 6

A lubrication system in which the oil cooler is in the scavenge subsystem, and the scavenged oil is cooled before it is returned to the tank.