Avs 3070 Exam 1 -Actual

Front 1

The thrust created by a turbine engine is based on Newton's ____________ law which states f=ma

Back 1

Newton's 2nd Law

Front 2

What is the main disadvantage of using a rocket engine to power a transport aircraft?

Back 2

Limited fuel burn

Front 3

What type of jet propulsion is being developed for hypersonic transportation?

Back 3

SCRAM Jet

Front 4

What type of gs turbine engine sends all the air from the intake into the engine core for thrust development?

Back 4

Turbojet

Front 5

What type of gas turbine engine sends air through large fans around the core of the engine?

Back 5

Turbo fan

Front 6

What type of gas turbine engine would be utilized on a helicopter?

Back 6

Turboshaft

Front 7

The ________ cycle describes the operating principles of a gas turbine engine.

Back 7

Brayton Cycle

Front 8

What effect does a diverging inlet duct have on air entering a turbine engine, assuming a subsonic aircraft?

Back 8

Increases air pressure
Decreases velocity

Front 9

Why are gas turbine engines preferred over reciprocating engines?

Back 9

Higher altitudes
Higher airspeeds
Less maintenance required

Front 10

From where does a gas turbine engine get the majority of its potential energy that is converted to heat energy and then into mechanical work?

Back 10

Jet fuel

Front 11

"You cannot create a gas turbine engine which extracts heat and converts it all to useful work" is a statement that best describes which law?

Back 11

Second law of thermodynamics

Front 12

As aircraft altitude increases, the thrust output of a gas turbine engine:

Back 12

decreases

Front 13

Subsonic gas turbine powered aircraft will utilize a _____________ duct in the exhaust nozzle to augment thrust.

Back 13

Divergent

Front 14

As air temperature increases, the thrust output of a gas turbine engine:

Back 14

Decreases

Front 15

"Amount of fuel in pounds required to produce 1 pound of thrust per hour" is a statement that best describes:

Back 15

Thrust specific fuel consumption

Front 16

The compressor in a gas turbine engine increases the ___________ of the airflow through the engine core.

Back 16

pressure

Front 17

Which type of gas turbine compressor has a higher compressor ratio per stage?

Back 17

Centrifugal

Front 18

What is the rotating component of a centrifugal compressor?

Back 18

Impeller

Front 19

What types of gas turbine engines utilize centrifugal compressors?

Back 19

Turboprops
Turboshafts
Small turbofans

Front 20

What two components make up one stage of an axial compressor?

Back 20

Rotor and stator

Front 21

The pressure of the air through a turbine engine increases each time it passes through a ____________ blade of an axial compressor.

Back 21

Stator

Front 22

On a 2-spool turbine engine, the low pressure turbine will drive the ______________________.

Back 22

Low pressure compressor (LPC)

Front 23

What is the main function of the turbine in a gas turbine engine?

Back 23

Drives the compressor.

Front 24

What material is used in the construction of turbine blades?

Back 24

Nickel alloys

Front 25

What type of turbine blade construction is the most creep-resistant?

Back 25

Single crystal

Front 26

The Rolls Royce Trent turbofan engine uses ___________ fan blades.

Back 26

Hollow titanium

Front 27

What is the best term used to describe modern turbofan fan blades?

Back 27

Wide Chord

Front 28

The fan section of a turbofan engine provides the ____________ in Newton's second law relating to jet thrust.

Back 28

Acceleration

Front 29

Turbofan engines with over 6,000 lb -thrust rating will use what type of starter?

Back 29

Air turbine

Front 30

On a turbofan engine, the starter engages and directly rotates the ____________.

Back 30

HPT

Front 31

On a two-spool turbofan engine, the N1 tachometer indicates the speed of the ____________.

Back 31

Low Pressure Compressor (LPC)

Front 32

On a two-spool turbofan, the N2 tachometer indicates the speed of the ___________________.

Back 32

High Pressure Compressor (HPC)

Front 33

The ___________________ is an indicator of thrust for turbofan engines.

Back 33

Engine pressure ratio

Front 34

On a three-spool engine like the Rolls Royce Trent turbofan, the N3 tachometer indicates the speed of the ___________.

Back 34

IPC

Front 35

Divergent air inlet ducts for turbofan engines have what effect on the air flow entering the engine?

Back 35

Create a ram effect going into the compressor, increasing the thrust.

Front 36

Why do supersonic aircraft use a convergent-divergent air inlet duct for the engine intake?

Back 36

The convergent duct slows down the supersonic air for the compressor

Front 37

What British scientist championed the development of the gas turbine engine for aircraft?

Back 37

Whittle

Front 38

At what point in a gas turbine engine is the air pressure at its highest?

Back 38

compressor discharge

Front 39

Where is the highest air velocity in a turbine engine?

Back 39

Turbine inlet

Front 40

Where is the highest temperature in a turbine engine that contacts materials?

Back 40

Turbine inlet nozzle

Front 41

Which of the following are secondary functions of compressor discharge air?

Back 41

Anti-ice
Turbine cooling
Cabin air conditioning

Front 42

If one can in a multiple-can combustion chamber fails because of a clogged fuel nozzle, the turbine is likely to be damaged because of the extreme ______________________ differences.

Back 42

temperature

Front 43

What is compressor pressure ratio?

Back 43

Ratio of pressure from the outlet compared to the inlet of the compressor.

Front 44

In an axial compressor, each rotor stage will have what effect on the velocity of the air?

Back 44

increase

Front 45

What type of combustor is used to reduce the overall length of a gas turbine engine?

Back 45

Reverse flow annular

Front 46

What is the name of the first stage of turbine stators?

Back 46

Turbine nozzle diaphragm (although it is also an inlet guide valve)

Front 47

Cooling the turbine blades allows for a high __________________.

Back 47

Turbine inlet temperature (T.I.T.)

Front 48

Which phrase best describes an equiaxed crystal structure for a turbine blade?

Back 48

Random orientation of the grains

Front 49

The flame tubes for can combustors serve what purpose?

Back 49

Aid in starting

Front 50

For any gas turbine engine, once spark and fuel have been added in the start sequence, light-off should happen within __________ seconds.

Back 50

10 seconds

Front 51

How can fuel flow be an indicator of an imminent hot start of a turbine engine?

Back 51

Fuel flow is high for a given engine speed

Front 52

The _____________ is an indicator of power output of a turboprop.

Back 52

Torquemeter

Front 53

A hot start is indicated by the ___________________ rising above its limit.

Back 53

Turbine inlet temperature (T.I.T.)

Front 54

What is a hung start?

Back 54

Engine does not accelerate to idle speed after light-off.