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Flashcards in Lubrication Deck (27)
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1
Q

What are the functions of lubricating oil in reciprocating engines

A

To reduce friction between moving parts and remove heat

2
Q

Name two important characteristics of aircraft engine oil

A

Oil must be light enough to circulate freely but heavy enough to provide the proper oil film at engine operating temperatures

3
Q

What could happen to an oil that is too low in viscosity at normal engine operating temperatures

A

becomes thin and the oil film between moving parts is easily broken, resulting in premature wear

4
Q

What are some of the factors that must be considered by an engine manufacturer in determining the proper grade of oil for particular engine

A

Operating load and temperature as well as the rotational speed

5
Q

Why do aircraft reciprocating engines use a relatively high viscosity oil

A

large operating clearance and operate at high temperatures and pressure

6
Q

Name some oil contaminants

A

Metal particles, dirt, carbon, moisture and acids

7
Q

What is possible indication of low oil pressure together with high oil temperature

A

A low oil supply

8
Q

Why do oil reservoirs have expansion space

A

To provide for oil foaming, thermal expansion, and air in the return oil

9
Q

What could cause oil foaming

A

Diluted oil, contaminated oil, and the oil level is too high

10
Q

What controls oil pressure in a gear type oil pressure pump

A

Oil pressure relief valve

11
Q

What function does an oil cooler bypass valve perform

A

It directs the oil either through the cooler or around it in order to maintain proper operating oil temperatures

12
Q

What could be a possible indication if the oil cooler passage becomes obstructed

A

A high oil temperature

13
Q

Where is the oil temperature bulb usually located

A

At the engine oil inlet

14
Q

What type of oil is used in a turbine engine oil system

A

Synthetic oil

15
Q

Where is the most critical point of lubrication in a gas turbine engine

A

At the turbine bearing

16
Q

What should be done if metal particles are found in an engine oil filter

A

Follow engine manufacturers maintenance instructions

17
Q

Name two types of turbine engine oil coolers

A

Air and fuel cooled

18
Q

What does the presence of metal particles in an engine oil filter indicate

A

usually indicates abnormal wear and possible engine internal failure

19
Q

What is the weight of aircraft engine oil

A

Approximately 7.5 pounds per U.S gallons

20
Q

What is the primary purpose of engine oil lubricate

A

To reduce friction.

21
Q

What is straight mineral oil

A

It is a lubricating oil and does not have any additives

22
Q

Is automotive oil suitable for aircraft engines

A

No

23
Q

Where can you find the grade of engine oil specified for a particular aircraft

A

Aircraft flight manual or pilots operating handbook for the aircraft

24
Q

What two instruments show the condition of a reciprocating engine lubrication system

A

Oil pressure and oil temperature gauge

25
Q

What type of oil quantity indicator is used in most aircraft engines

A

Dipstick that measures the quantity of the oil in the tank sump

26
Q

When should the engine oil quantity be checked on a turbine engine

A

As soon as possible after engine is shut down

27
Q

A reciprocating engine is found to have excessive oil consumption without evidence of any oil leaks. Heat is the likely cause

A

Piston rings are worn or broken