Vayudoot Aviation

1.
An impulse turbine is a turbine in which the expansion takes place

in the stator and in the rotor

in order to produce a degree of jet propulsion < 1/2.

fully in the rotor

fully in the stator

2.
The reason for having a low pressure fuel-cooled oil cooler in a recirculatory type oil system is to

cool the oil and heat the fuel

cool the oil only.

heat the fuel only.

cool both the oil and the fuel.

3.
The disadvantages of axial flow compressors compared to centrifugal flow compressors are :1 - expensive to manufacture2 - limited airflow3 - greater vulnerability to foreign object damage4 - limited compression ratioThe combination of correct answers is

03-Jan

04-Fev

03-Fev

02-Jan

4.
On the ground, the Auxiliary Power Unit (APU) can be substituted for the

ground power unit

ground power unit, the starting system, the air conditioning unit.

ground power unit, the starting system

ground power unit, the air conditioning unit

5.
In addition to fire detention/protection, most auxiliary power units (APUs) have automatic controls for stating, stopping and maintaining operation within safe limits. These controls provide correct sequencing of the starting cycle as well as protection against

high TGT and loss of oil pressure only

overspeed and high oil temperature only.

high TGT only.

high turbine gas temperature (TGT), overspeed, loss of oil pressure and high oil temperature

6.
Using compressor bleed air to power systems

decreases aircraft performance

increases aircraft performance

has no influence on aircraft performance

is limited to the phases of take-off and landing

7.
A modern Auxiliary Power Unit (APU) is designed to provide power for ground starting of an engine. It also supplies both in the air (subject to certification limitations) and on the ground

air conditioning and thrust in the event of engine failure

air conditioning and electrical services

air conditioning and electrical services (on the ground) electrical and hydraulic back-up services (in the air).

either air conditioning or electrical services, but never both at the same time.

8.
The control of free turbine engines on turboprops, is accomplished by:- a propeller control lever used to select: 1 - propeller RPM 2 - turbine temperature 3 - turbine RPM- a fuel control lever used to select: 4 - propeller RPM 5 - torque 6 - turbine temperature The combination which regroups all of the correct statements is

01-05-06

01-03-05

03-04-06

02-04-05

9.
For a turbine engine, the term self-sustaining speed relates to the speed at which the engine

will enable the generators to supply bus-bar voltage.

will run without any external assistance

operates most efficiently in the cruise

is designed to idle after starting

10.
The pressure usually produced by the Boost Pumps (BP) of the fuel supply system is within the following range

20 to 50 psi

5 to 10 psi

300 to 500 psi

3000 to 5000 psi

11.
The primary reason for a limitation being imposed on the temperature of gas flow is to

ensure that the maximum acceptable temperature at the turbine blades is not exceeded

ensure that the maximum acceptable temperature within the combustion chamber is not exceeded

prevent damage to the jet pipe from overheating

prevent overheating and subsequent creep of the nozzle guide vanes

12.
The accessory units driven by the accessory gearbox of a turbo-jet engine are the :1. tacho-generator N12. tacho-generator N23. thrust reverser pneumatic motors4. AC generator and its Constant Speed Unit (CSD)5. oil pumps6. hydraulic pumps7. high pressure fuel pumpsThe combination regrouping all the correct statements is

4, 5, 6, 7.

1, 4, 5, 6, 7.

2, 4, 5, 6.

2, 3, 4, 5, 6, 7.

13.
For a fan jet engine, the by-pass ratio is the

internal airflow mass divided by the external airflow mass

internal airflow mass divided by the fuelflow mass

external airflow mass divided by the internal airflow mass

fuelflow mass divided by the internal airflow mass

14.
A stage in an axial compressor

has a compression ratio in the order of 2.1

is made of a rotor disc followed by a row of stator blades

has a compression ration in the order of 0.8

is made of row of stator blades followed by a rotor disc

15.
The purpose of the blow-in-doors at the air inlets is to

provide the engine with additional air at high power settings at cruising speed

feed cooling air to the engine cowling

serve to increase the relative velocity at the first compressor stage

provide the engine with additional air at high power settings and low air speeds

16.
In a gas turbine engine, compressor blades, which are not rigidly fixed in position when the engine is stationary, take up a rigid position when the engine is running due to

the resultant of aerodynamic and centrifugal forces

blade creep

thermal expansion

oil pressure

17.
In a gas turbine engine, the maximum gas temperature is attained

across the turbine

at the entry to the exhaust unit.

in the cooling airflow around the flame tube.

within the combustion chamber

18.
The fan in a high by-pass ratio turbo-jet engine produces

none of the thrust

the lesser part of the thrust

half the thrust

the greater part of the thrust

19.
In a gas turbine engine, the power changes are normally made by controlling the amount of

air leaving the compressor by the opening or closing of bleed valves

air entering the compressor and fuel entering the combustion chambers

fuel supplied

air entering the compressor

20.
An engine pressure ratio (EPR) gauge reading normally shows the ratio of

compressor outlet pressure to compressor inlet pressure

jet pipe pressure to compressor inlet pressure

jet pipe pressure to combustion chamber pressure

combustion chamber pressure to compressor inlet pressure

21.
In a single spool gas turbine engine, the compressor rpm is

less than turbine rpm

the same as turbine rpm

independent of turbine rpm

greater than turbine rpm.

22.
The Engine Pressure Ratio (EPR) is the ratio of

the total turbine outlet pressure to the total compressor outlet pressure

the total turbine inlet pressure to the total compressor outlet pressure

the total turbine outlet pressure to the total compressor inlet pressure

the total turbine inlet pressure to the total compressor inlet pressure

23.
In a fuel system, the oil to fuel heat exchanger allows

fuel cooling so as to prevent vapour creation likely to unprime nozzles

fuel heating as required whenever fuel filter clogging is detected

jet engine oil cooling through thermal exchange with fuel flowing from tanks.

automatic fuel heating by the engine oil so as to prevent icing in fuel filter.

24.
The purpose of the barometric correction in a fuel controller is to

increase the fuel-to-air ratio when altitude increases

maintain the correct weight fuel to air ratio when the altitude increases

maintain a constant fuel metering whatever the altitude

reduce the fuel-to-air ratio when altitude increases

25.
The thrust of a turbo-jet, at the selection of full power :1 - equals the product of the exhaust gas mass flow and the exhaust gas velocity2 - is obtained by pressure of the exhaust gas on the ambient air3 - is equivalent to zero mechanical power since the aeroplane is not moving4 - is independant of the outside air temperatureThe combination which regroups all of the correct statements is

03-Fev

03-Jan

4

02-Jan

26.
A reverse thrust door warning light on the flight deck instrument panel illuminates when

the reverser doors have moved to the reverse thrust position

the reverser doors are unlocked

the reverser doors are locked

reverse has been selected but the doors have remained locked

27.
In the axial flow compressor of a turbo-jet engine, the flow duct is tapered. Its shape is calculated so as to

reduce the axial speed, whatever the engine rating

maintain a constant axial speed in cruising flight

maintain a constant axial speed whatever the engine rating

reduce the axial speed in cruising flight

28.
The compressor surge effect during acceleration is prevented by the

variable setting type nozzle guide vanes

Fuel Control Unit (F.C.U.).

inlet guide vanes

surge bleed valves

29.
The fuel temperature, at which, under standard conditions, the vapour ignites in contact with a flame and extinguishs immediately, is the

combustion point

flash point

fire point

self ignition point

30.
In a turbo-jet, the purpose of the turbine is to

compress the air in order to provide a better charge of the combustion chamber

clear the burnt gases, the expansion of which provide the thrust

drive devices like pumps, regulator, generator

drive the compressor by using part of the energy from the exhaust gases

31.
Consider a jet engine whose control is based on the Engine Pressure Ratio (EPR):1. with a constant EPR, the thrust decreases when the altitude increases2. with a constant EPR, the thrust is independent of the Mach number3. At same environmental conditions, a given EPR setting maintains the thrust irrespective of engine wear due to ageing.4. the EPR is determined by the impact pressure difference between the turbine outlet and the compressor inlet5. on take-off, in the event of icing not detected by the crew, the indicated EPR is lower than the real EPRThe combination regrouping all the correct statements is

3, 4, 5.

2, 3, 4.

1, 3.

1, 5.

32.
A ""fan"" stage of a ducted-fan turbine engine is driven by

the low pressure turbine

the high pressure compressor through reduction gearing.

airflow drawn across it by the high pressure compressor

the high pressure turbine

33.
The use of igniters is necessary on a turbo-jet:1 - throughout the operating range of the engine2 - for accelerations3 - for ground starts4 - for in-flight relights5 - during turbulence in flight6 - under heavy precipitation or in icing conditionsThe combination which regroups all of the correct statements is

3

3 - 4 - 5 - 6

1

2002-03-04

34.
An impulse coupling does not function at such speeds above those encountered in starting. Its engaging pawls are prevented from operating at higher speeds by

centrifugal force

a coil spring

electro-magnetic action of operating magneto.

engine oil pressure

35.
. Turbine blade stages may be classed as either ""impulse"" or ""reaction"". In an impulse blade section

the pressure drops across the nozzle guide vanes and remains constant across the rotor blades

the pressure remains constant across the nozzle guide vanes and rises constant across the rotor blades

the pressure remains constant across the nozzle guide vanes and drops across the rotor blades

the pressure rises across the nozzle guide vanes and remains constant across the rotor blades

36.
A ""hung start"" is the failure of an engine to accelerate to its normal idle speed. It may be caused by

failure of the fuel to ignite in the starting sequence after the engine has been accelerated to the required rpm by the starter

the starter cutting out early in the starting sequence before the engine has accelerated to the required rpm for ignition

an attempt to ignite the fuel before the engine has been accelerated sufficiently by the starter

compressor surging

37.
In very cold weather, the pilot notices during startup, a slightly higher than normal oil pressure.This higher pressure

is abnormal but does not require the engine to be shut down.

is normal, if it decreases after startup.

requires an oil change

is abnormal and requires the engine to be shut down

38.
In a free turbine engine

its shaft may be connected to either a compressor or another turbine.

the air enters the compressor via the input turbine.

the compressor and power output shaft are mechanically connected.

there is no mechanical connection between the compressor and the power output shaft

39.
When the combustion gases pass through a turbine the

pressure drops

velocity decreases

temperature increases

pressure rises

40.
In a compressor stage of a jet engine, the sequence is

stator - stator - rotor

stator - rotor

rotor - rotor - stator

rotor - stator

41.
If air is tapped from a gas turbine HP compressor, the effect on the engine pressure ratio (EPR) and the exhaust gas temperature (EGT) is that

both EPR and EGT decrease

EPR decreases and EGT remains constant

EPR decreases and EGT increases

EPR remains constant and EGT increases

42.
In the stator of a turbine, the speed V and static pressure Ps vary as follows

V decreases, Ps decreases

V decreases, Ps increases

V increases, Ps decreases

V increases, Ps increases

43.
The primary purpose of the bleed valves fitted to axial flow compressors is to

enable an external air supply to spin up the compressor for engine starting

reduce the likelihood of compressor stall

control the acceleration time of the engine.

spill compressor air should the engine overspeed thus controlling the speed

44.
Use the appendix to answer this question)The gas turbine illustrated is of the following type

free turbine and axial compressor

single shaft turbine and centrifugal compressor

free turbine and centrifugal compressor

single shaft turbine and axial compressor

45.
At constant fuel flow, if engine compressor air is bled off for engine anti-icing or a similar system, the turbine temperature

will be unchanged

will fall.

will rise

may rise or fall depending on which stage of the compressor is used for the bleed and the rpm of the engine at the moment of selection.

46.
Concerning the centrifugal compressor, the compressor diffuser is a device in which the

pressure rises and velocity falls

pressure rises at a constant velocity

velocity, pressure and temperature rise

velocity rises and pressure falls

Question Bank

Questions for INDIGO JET ENGINES (955-1001)

An impulse turbine is a turbine in which the expansion takes place

The reason for having a low pressure fuel-cooled oil cooler in a recirculatory type oil system is to

The disadvantages of axial flow compressors compared to centrifugal flow compressors are :1 - expensive to manufacture2 - limited airflow3 - greater vulnerability to foreign object damage4 - limited compression ratioThe combination of correct answers is

On the ground, the Auxiliary Power Unit (APU) can be substituted for the

In addition to fire detention/protection, most auxiliary power units (APUs) have automatic controls for stating, stopping and maintaining operation within safe limits. These controls provide correct sequencing of the starting cycle as well as protection against

Using compressor bleed air to power systems

A modern Auxiliary Power Unit (APU) is designed to provide power for ground starting of an engine. It also supplies both in the air (subject to certification limitations) and on the ground

For a turbine engine, the term self-sustaining speed relates to the speed at which the engine

The pressure usually produced by the Boost Pumps (BP) of the fuel supply system is within the following range

The primary reason for a limitation being imposed on the temperature of gas flow is to

For a fan jet engine, the by-pass ratio is the

A stage in an axial compressor

The purpose of the blow-in-doors at the air inlets is to

In a gas turbine engine, compressor blades, which are not rigidly fixed in position when the engine is stationary, take up a rigid position when the engine is running due to

In a gas turbine engine, the maximum gas temperature is attained

The fan in a high by-pass ratio turbo-jet engine produces

In a gas turbine engine, the power changes are normally made by controlling the amount of

An engine pressure ratio (EPR) gauge reading normally shows the ratio of

In a single spool gas turbine engine, the compressor rpm is

The Engine Pressure Ratio (EPR) is the ratio of

In a fuel system, the oil to fuel heat exchanger allows

The purpose of the barometric correction in a fuel controller is to

A reverse thrust door warning light on the flight deck instrument panel illuminates when

In the axial flow compressor of a turbo-jet engine, the flow duct is tapered. Its shape is calculated so as to

The compressor surge effect during acceleration is prevented by the

The fuel temperature, at which, under standard conditions, the vapour ignites in contact with a flame and extinguishs immediately, is the

In a turbo-jet, the purpose of the turbine is to

A ""fan"" stage of a ducted-fan turbine engine is driven by

An impulse coupling does not function at such speeds above those encountered in starting. Its engaging pawls are prevented from operating at higher speeds by

. Turbine blade stages may be classed as either ""impulse"" or ""reaction"". In an impulse blade section

A ""hung start"" is the failure of an engine to accelerate to its normal idle speed. It may be caused by

In very cold weather, the pilot notices during startup, a slightly higher than normal oil pressure.This higher pressure

In a free turbine engine

When the combustion gases pass through a turbine the

In a compressor stage of a jet engine, the sequence is

If air is tapped from a gas turbine HP compressor, the effect on the engine pressure ratio (EPR) and the exhaust gas temperature (EGT) is that

In the stator of a turbine, the speed V and static pressure Ps vary as follows

The primary purpose of the bleed valves fitted to axial flow compressors is to

Use the appendix to answer this question)The gas turbine illustrated is of the following type

At constant fuel flow, if engine compressor air is bled off for engine anti-icing or a similar system, the turbine temperature

Concerning the centrifugal compressor, the compressor diffuser is a device in which the