Jeppesen Oral- Chapter 9 (Lubrication Systems)

Answer 1

faulty piston rings

Answer 2

Clean, cushion, cool, reduce friction, hydraulic medium

Answer 3

Light enough to circulate freely Viscous enough to provide cushioning

Answer 4

Becomes too thin, cause more damage

Answer 5

Operating load and temperature as well as rotational speed

Answer 6

To provide sufficient cushioning for momentary loads, To provide sufficient thickness for containment entrapment

Answer 7

Metal particles, dirt, carbon, moisture and acids

Answer 8

low oil supply

Answer 9

Causes slugging materials to repel each other and remain in suspension long enough to be trapped by oil filter or drained

Answer 10

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

Answer 11

Diluted oil, contaminated oil, and oil level being to high

Answer 12

Oil pressure relief valve

Answer 13

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

Answer 14

high oil temperature

Answer 15

At the engine oil inlet

Answer 16

Indicates abnormal wear and imminent engine failure

Answer 17

Follow engine manufactures maintenance instruction

Answer 18

Turbine bearings

Answer 19

Synthetic oil

Answer 20

main oil pressure system, scavenge system and just before oil jet (last chance filter)

Answer 21

Air cooled Fuel cooled

Answer 22

It may become so thin, film is not thick enough and metal to metal contact happens

Question 23

Is the oil temperature shown on the aircraft instrument panel the temperature of the oil entering the engine or of the oil leaving the engine?

Answer 23

It is the temperature of the oil entering the engine.

Question 24

What is the purpose of oil dilution in a reciprocating engine?

Answer 24

When very cold weather is anticipated, gasoline can be mixed with the lubricating oil before the engine is shut down. This reduces the viscosity of the oil and makes starting easier. When the engine is running, the gasoline evaporates out of the oil.

Question 25

What is the function of the hopper in the oil tanks used with some reciprocating engines?

Answer 25

Hoppers are a part of the oil dilution system. Only the oil in the hopper is diluted. This speeds up dilution and requires less gasoline.

Question 26

What happens to the gasoline that is used to dilute the oil in the crankcase of an aircraft reciprocating engine?

Answer 26

When the engine is sunning and the oil is warm, the gasoline evaporates out of it.

Question 27

What is the purpose of the sludge plugs in the crankshaft of a reciprocating engine?

Answer 27

They trap sludge that is in the oil and hold it until the engine is disassembled at overhaul.

Question 28

Which pump is the larger in a dry-sump lubricating system, the pressure pump or the scavenger pump?

Answer 28

The scavenger pump has the greater volume.

Question 29

Why do full-flow oil filters have a spring-operated bypass valve in them?

Answer 29

In case the filter should plug up so it cannot pass any oil, the bypass valve will open and allow unfiltered oil to flow through the system.

Question 30

Where are the last chance filters located in a turbojet engine?

Answer 30

They are located inside the engine just ahead of the nozzles that spray oil onto the bearings.