ch.6 Lubricating and cooling FAA powerplant book

To be most useful as a preservative oil for long term storage, which should be one characteristic of that oil?

High Viscosity

What is the source of most of the heat that is absorbed by the lubricating oil in a reciprocating engine?

Pistons and cylinder walls

The viscosity of a liquid is a measure of its:

resistance to flow

If the flash point of an aviation oil is too low, during operations at elevated temperatures, it will:

produce flammable vapors

Upon what quality or characteristic of a lubricating oil is its viscosity index based?

Its rate of change in viscosity with temperature change

Which of the following factors helps determine the proper grade of oil to use in a particular engine?

Operating speeds of bearings

Specific gravity is a comparison of the weight of a substance to the weight of an equal volume of:

distilled water at a specific temperature

What type of oil do most engine manufacturers recommend for new reciprocating engine break-in?

Straight mineral oil

What type of oil do most engine manufacturers recommend after new reciprocating engine break-in?

Ashless-dispersant oil

If an oil filter element becomes completely clogged, the:

the oil pump will supply unfiltered oil

An oil tank having a capacity of 5 gallons, must have an expansion space of:

2 quarts

In order to maintain a constant oil pressure as the clearances between the moving parts of an engine increase through normal wear, the supply pump output:

remains relatively constant at a given rpm with less oil being returned to the pump inlet by the relief valve

Why is an aircraft reciprocating engine oil tank on a dry sump lubricating system equipped with a vent line?

To prevent pressure buildup in the oil tank

What is the primary purpose of the hopper located in the oil supply tank of some dry sump engine installations?

To reduce the time required to warm the oil to operating temperature

In what location (flow sequence) on a reciprocating engine is the main oil filter located?

Just after exiting the oil pressure pump

On a gear type oil pump consisting of a drive gear and an idler gear:

one gear turns clockwise, and the other turns counter clockwise

A Bourdon tube type oil pressure gauges measures the difference in oil pressure between a location:

after the oil pump and the atmosphere

Where is the oil temperature bulb located on a dry sump reciprocating engine?

Oil inlet line

In order to relieve excess pump pressure in an engine's internal oil system, most engines are equipped with a:

relief valve

A floating control thermostat is used on some reciprocating aircraft engines. How does this device help to regulate oil temperature?

It controls air flow through the oil cooler

If the oil in the oil cooler core and annular jacket becomes congealed, what unit prevents damage to the cooler?

Surge protection valve

Cylinder walls are usually lubricated by:

splashed or sprayed oil

The oil temperature regulator is usually located between which of the following on a dry sump reciprocating engine?

the scavenge pump outlet and the oil storage tank

The pumping capacity of the scavenger pump in a dry sump aircraft engine's lubrication system:

is greater than the capacity of the oil pressure pump

What is the primary purpose of changing aircraft engine lubricating oils at predetermined periods?

The oil becomes contaminated with moistures, acids, and finely divided suspended solid particles

When does the oil cooler bypass valve open?

When oil temperature falls below a specified amount

Compared to reciprocating engine oils, the types of oils used in turbine engines:

have less tendency to produce lacquer or coke

From what source is secondary cooling air acquired in a turbine engine in order to provide additional cooling of the turbine bearings?

compressor bleed air

Which of the following prevents oil from entering the main accessory case of a turbine engine when the engine is not running?

check valve

Oil picks up the most heat from which of the following turbine engine components?

exhaust turbine bearing

Which of the following is a function of the fuel oil heat exchanger on a turbojet engine?

Increases fuel temperature.

What is the purpose of the relief valve installed in the venting system of a turbine engine oil tank?

Prevent oil pump cavitations by maintaining positive pressure on its inlet

The type of oil pump most commonly used on turbine powered engines are classified as:

positive displacement.

What is the purpose of a last chance oil filter?

to prevent clogging of the oil spray nozzles that spray the main bearings

What is the primary purpose of the oil breather pressurization system that is used on turbine engines?

Provides a proper oil spray pattern from the main bearing oil jets.

Which type of valve prevents oil from entering the main accessory case when the engine is not running?

check

What is used on most turbine engines to monitor engine wear possibly providing notification in advance of an internal engine problem?

magnetic chip detectors at key oil scavenge locations

What does oil pressure depend on in most modern turbofan engines?

engine RPM

The greatest portion of heat generated by combustion in a typical aircraft reciprocating engine is:

carried out with the exhaust gases.

What is the function of a blast tube as used on aircraft reciprocating engines?

a device to cool an engine accessory

The primary purpose of baffles and deflectors installed around cylinders of air-cooled aircraft engines is to:

force cooling air into close contact with all parts of the cylinders.

During climb, cowl flaps are left:

partially open

1. Some exhaust systems include an augmenter system to draw additional air over the engine for cooling.

2. Augmenter systems are used to create a low pressure area at the lower rear of the aircraft engine cowling.

Regarding the above statements,

Both No. 1 and No. 2 are true.

Where are cooling fins located on the outside of air-cooled engines?

cylinder heads and cylinder barrels

Which of the following defects would likely cause a hot spot on a reciprocating engine cylinder?

too much cooling fin area broken off

A bent cooling fin on an aluminum cylinder head should be:

left alone if no crack has formed

How are combustion liner walls cooled in a gas turbine engine?

by secondary air flowing through the combustion chamber

What air is used to cool the exterior and nacelle of a turbofan engine?

fan air