Lubrication Systems

Question 1

What is meant by the viscosity of engine lubricating oil?

Answer 1

The resistance of the oil to flow

Question 2

What is meant by as wet sump lubrication system?

Answer 2

A lubrication system in which the oil is carried inside the engine itself

Question 3

What is meant by a dry sump lubrication system?

Answer 3

A lubrication system in which the oil is carried in a tank that is not a part of the engine

Question 4

How is oil temperature controlled in an aircraft reciprocating engine?

Answer 4

Hot oil is directed through the core of the oil cooler, but cold oil is directed around the outside of the core so it will not be further cooled

Question 5

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 5

It is the temperature of the oil entering the engine

Question 6

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

Answer 6

In very cold weather, gasoline can be mixed with oil before shut down. It reduces the viscosity of oil, starts easier. When engine is running, gasoline evaporates out of oil

Question 7

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

Answer 7

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 8

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

Answer 8

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

Question 9

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

Answer 9

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

Question 10

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

Answer 10

The scavenger pump has greater volume

Question 11

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

Answer 11

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 12

What is the function of a fuel-oil heat exchanger in the lubrication system of a turbojet engine?

Answer 12

This allows heat from the oil to warm the fuel so ice will not form on the fuel filters

Question 13

What kind of oil is used in most turbojet engines?

Answer 13

Synthetic oil

Question 14

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

Answer 14

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

Question 15

Where is the oil thank in a dry sump reciprocating engine vented?

Answer 15

To the engine crankcase

Question 16

What information must be displayed around the oil filter opening for a turbojet engine?

Answer 16

The word “oil” and the permissible oil designations, or references to the Airplane Flight Manual (AFM) for permissible oil designations

Question 17

What is the function of the oil control rings on the piston of an aircraft reciprocating engine?

Answer 17

They maintain the proper quantity of oil between the piston and the cylinder wall.

Question 18

What is meant by a spectromatic oil analysis?

Answer 18

Program for samples taken at regular intervals sent to a lab for analysis , burned in electric arc.
Light detected in wavelength show elements present in oil sample.
Aluminum - wear of pistons or wrist pin plugs
Iron - wear of cylinder walls or piston rings
Copper - wear of Main bearings or bushings
Cannot be done with single sample, must be at regular intervals to measure change in amounts

Question 19

What indication would a pilot have if his oil supply was low?

Answer 19

The oil temperature would be high and the oil pressure would be low

Question 20

What is meant by a hot tank lubrication system?

Answer 20

A lubrication system in which the oil cooler is located in the pressure subsystem

Question 21

What is meant by a cold tank lubrication system?

Answer 21

A lubrication system in which the oil cooler is located in the scavenge subsystem. The oil that is returned to the tank has been cooled