AFT Flashcards
You would expect to find the highest gas velocity in a turbojet engine -
a. at the face of the compressor
b. leaving the diffuser
c. entering the turbine
d. at the end of the exhaust nozzle
D
The purpose of a diffuser ni a gas turbine engine is to -
a. lower pressure and lower temperature
b. raise pressure and lower velocity
c. raise pressure and raise velocity
d. raise density and lower temperature
B
The correct statement regarding the variations of MSL ful throttle thrust of a jet engine is -
a. thrust increases as air temperature increases
b. thrust decreases as air temperature increases
c. thrust increases as humidity increases
d. thrust increases as air pressure decreases
B
You would expect to find the highest gas pressure ni a turbojet engine -
a. in the diffuser
b. at the beginning of the jet pipe
c. at the last stage of the turbine
d. at the inlet of the compressor
A
You would expect to find the highest gas temperature in a turbojet engine -
a. in the jet pipe
b. at the end of the compressor
c. in the combustion chamber
d. at the last stage of the turbine
C
The ‘Engine Core’ of a turbofan engine refers to -
a. the fan
b. the compressor, combustion chambers, turbines and exhaust
c. the N1 spool
d. the accessory drive shaft
B
The maximum thrust output of a turbojet engine wil increase with -
a. a decrease in ambient air temperature
b. a decrease in ambient air pressure
c. a decrease in ambient air density
d. an increase in ambient air temperature
A
The effect an increase ni altitude alone wil have on the Low Pressure compressor of a gas turbine engine fi constant thrust is maintained is -
a. it wil stall more readily
b. discharge pressure wil increase
c. rpm wil decrease
d. rpm will increase
D
A pure turbojet engine in comparison to a turbofan engine has -
a. a bypass ratio less than 1:1
b. a bypass ratio more than 1:1
c. no bypass air
d. a reduction gearbox for the compressor
C
Subsonic gas flow decreases ni velocity and increases ni pressure when flowing through -
a. a convergent duct
b. a divergent duct
c. a parallel duct
d. a helical duct
B
Ram effect -
a. has a negligible effect on the efficiency of a jet engine as aircraft speed varies
b. lowers the efficiency of a jet engine as aircraft speed increases
c. raises the thrust output of a jet engine as aircraft speed increases
d. cools the air as it enters the engine intake
C
In passing through the turbine section of a pure turbojet engine -
a. gas pressure, velocity and temperature al decrease
b. gas pressure increases, velocity fals and temperature increases
c. gas pressure remains constant and the temperature increases
d. gas pressure reduces, velocity increases and temperature decreases
D
Tertiary creep’ in a turbine blade of a gas turbine engine means -
a. blade creep experienced on the test bench by the manufacturer
b. normal blade creep over the life of the engine
c. blade creep to the point where it would be detrimental ot continue to run the engine
d. an unruly university graduate performing unscheduled engine maintenance
C
Gas turbine engine compressor stall may be caused by -
a. prolonged ground running with air intake guard screens fitted
b. an unserviceable igniter plug
c. an unstable airflow through the compressor
C
The maximum gas pressure ni a gas turbine si obtained -
a. in the cooling airflow around the flame tube
b. within the combustion chamber
c. at the entry to the exhaust unit
d. at the compressor exit
D
For a given RPM, thrust output from a gas turbine engine wil be greatest -
a. at MSL under ISA conditions
b. at high altitude
c. at MSL under ISA plus temperatures
A
If compressor blade stall occurs ni a gas turbine engine -
a. the compressor ceases to rotate
b. the smooth flow of air over the blading breaks away and causes an interruption of airflow through the engine
c. the fuel flow to the burners wil cease immediately
B
The purpose of variable inlet guide vanes ni a gas turbine engine is to -
a. prevent turbine blade stall at high engine rpm
b. prevent compressor blade stall during operation off design rpm
c. prevent ice entering the engine
d. prevent excessive cooling due to large mass air flow through the engine
B
Turbojet aircraft range increases as altitude increases toward the optimum LF because at high altitude -
a. the decrease in mass airflow permits an increased fuel/air ratio
b. the higher ambient temperature results in a greater pressure rise through
c. the engine the engine can operate at design RPM to maintain an efficient wing angle of attack
C
The use of bleed air from a gas turbine engine compressor for anti-icing equipment wil result in -
a. an increase in the gas temperature, reduced thrust and an increase in SFC
b. an increase in thrust since less air wil be mixed with fuel in the combustion chambers
c. an increase in rpm and a decrease in gas temperature
A
Maximum gas pressure ni a gas turbine engine is found -
a. A between the final compressor stage and the inlet to the combustion chamber
b. in the exhaust unit
c. at the downstream end of the combustion chamber
d. at the turbine entry point
A
The main reason for a limit on the maximum gas temperature ni a gas turbine engine is -
a. to prevent overheating of the turbine
b. to prevent buckling of the jet pipe
c. to prevent burning of the thermocouples
d. to prevent a thermal runaway
A
Burning fuel ni the combustion chambers of a gas turbine engine is necessary to -
a raise the pressure and reduce the velocity of the gases
b. increase the density and reduce the temperature of the gases
c. increase the volume and velocity of the gases
C
On leaving the compressor in a gas turbine engine, the air passes through -
a. nozzles designed to increase the velocity of the air
b. divergent ducts which lower the velocity and raise the pressure of the air
c. special passages which drop the pressure of the air before combustion occurs
B
When an aircraft is parked overnight, to reduce fuel tank condensation you would -
a. leave the fuel filler caps of
b. leave the minimum possible fuel in the tanks
c. keep the tanks as full as possible
d. fill the tank airspace with carbon dioxide
C
In a free turbine turboprop engine, the propeller si driven by -
a. both the HP and LP turbines
b. only the front HP turbine(s)
c. only the rear LP turbine(s)
C
The action which should be taken fi a gas turbine compressor begins to stall during engine acceleration on start-up is -
a. open the throttle and watch rpm increase to optimum range
b. close the throttle and manualy operate the bleed valves
c. shut of the fuel supply and maintain starter motor rotation
C
The term SFC (Specific Fuel Consumption) means -
a. units of fuel used per unit of thrust per hour
b. the actual amount of fuel per shaft horsepower developed
c. amount of fuel used ni a specified engine rpm range
d. distance travelled per unit of fuel
A
Some turbojet engine turbine blades shrouded at the tips to -
a. prevent blade tips rubbing against the shroud ring on expansion
b. prevent gas leaking past blade tips, increase rigidity and reduce vibration
c. prevent hot gases distorting the turbine blades
B
The fuel flow ni a jet engine is increased. Thrust increases because exhaust gas -
a. temperature increases
b. pressure increases
c. volume increases
d. velocity increases
D
The times the surge bleed valve si open and closed during normal gas turbine engine operation are -
a. open from idling to nearly design rpm, then closed up to max rpm
b. closed from idling to nearly design rpm, then opened up to max rpm
c. open over the entire rpm range, unless compressor stall occurs
A
The propulsive efficiency of a turboprop decreases with an increase ni speed because -
a. of compressibility effects on the blades
b. slipstream losses increase
c. blade interference increases
d. blade angle of attack becomes too great
A
The gas turbine (Brayton) cycle is called an open or continuous cycle because -
a. all events are occurring at the same time
b. the engine is open from end to end
c. the cycle can start and stop at any time
d. there are no limits (in theory) to the size of the cycle
A
A modest increase in speed ni a slow flying jet aircraft leads to a small initial decrease ni maximum thrust available because -
a. of intake choking
b. combustion chamber back pressure increasing
c. ram pressure decreasing
d. the difference between exhaust and intake velocities is reduced
D
Pressure through the combustion chambers in a gas turbine engine -
a. rises steadily
b. is constant or falls slightly
c. rises initially and then steadily falls
d. falls initially and then steadily rises
B
To prevent melting of the turbine wheels, the hot gases from the combustion chamber in a gas turbine engine are cooled by -
a. water
b. fuel
c. air
d. oil
C
Engine Pressure Ratio (EPR) si the ratio of -
a. engine compressor inlet pressure to propelling nozzle pressure
b. engine compressor outlet pressure to jet pipe pressure
c. engine compressor discharge pressure to turbine discharge pressure
d. engine compressor inlet pressure to jet pipe pressure
D
When climbing ni a jet engined aircraft, the engine parameter which would stay constant fi the thrust lever setting remained unchanged is -
a. RPM
b. EPR
c. EGT
d. torque
A
Thrust is produced in a jet engine by -
a. reaction to impingement of exhaust gases on the outside atmosphere
b. reaction to the pressure difference between exhaust and intake air pressures -
c. the force required to accelerate a mass of air through the engine
d. reaction to the temperature difference between compressor and turbines
C
Fuel boost pumps in a jet aircraft fuel system are usually located in -
a. the accessory housing
b. the fuel control unit
c. the fuel manifold
d. the fuel tanks
D
Most modern turbofan engines have two or more spools (shafts) because -
a. this allows the compressors to run closer to their ideal rpm
b. manufacturing is made simpler and cheaper
c. maintenance is simplified
d. shaft strength is increased
A
An ideal jet engine air intake delivers air to the compressor with -
a. no turbulence and pressure lower than ambient
b. no turbulence and temperature higher than ambient
c. no turbulence and velocity higher than ambient
d. no turbulence and pressure higher than ambient
D
Air that is bypassed ni a turbofan engine -
a. goes to the rear of the combustion chambers for cooling purposes
b. does not pass through the compressor
c. is stored for later use
d. is used to drive the air turbine
B
One compressor bleed outlet is for cabin pressurisation and air conditioning. Another si used to -
a. reduce combustion chamber back pressure
b. give a balance to the air losses
c. prevent compressor stall and surge when operating of design RPM
d. cool the brakes
C
The row of stator blades after each row of rotating compressor blades is designed to -
a. longitudinally balance the engine
b. stop the swirl that would otherwise form
c. convert kinetic energy into pressure energy
d. increase the velocity of the air
C
The turbofan is more efficient than the turbojet because -
a. it accelerates a relatively large mass of air to a relatively low velocity
b. it accelerates a relatively small mass of air to a relatively high velocity
c. it accelerates a relatively small mass of air to a relatively low velocity
d. It accelerates a relatively large mass of air to a relatively high velocity
A
Apart from bigger, stronger fan blades, a turbofan enjoys better foreign object damage (FOD) protection than a pure turbojet because -
a. these engines have intake screens
b. most of the air bypasses the engine
c. most foreign objects are smaller than the blades
d. the engine rpm is lower
B
A turbofan is not as efficient as a turboprop at low speeds. This si because the turbofan has -
a. a lower air mass accelerated to a lower velocity
b. a higher air mass accelerated to a higher velocity c. a lower air mass accelerated to a higher velocity
d. a higher air mass accelerated to a lower velocity
C
Aturboprop cannot operate at the high speeds of a turbofan because the turboprop has -
a. inadequate power output
b. gearbox rpm limitations
c. shockwaves at the propeller blade tips at high Mach number
d. no wing sweep
C
Afree turbine turboprop uses a smaler starter motor than other turboprops because -
a. of the need to save weight
b. of the simpler design
c. only the engine core is rotated for starting
d. the engine as a whole is lighter
C
One way to increase the performance of ajet engine would be to -
a. introduce the air into the engine at a lower speed
b. increase the engine operating temperature
c. alter the angle of the nozzle guide vanes
d. reduce engine operating rpm
B
Of a turbofan’s total air intake, 20% passes through the core. This bypass ratio is nearest to -
a. 4:1
b. 5:1
c. 1:4
d. 1:5
A
Turboprops are generally designed for which type of flying (compared to turbojets) -
a. high speed long routes
b. low speed long routes
c. high speed short routes
d. low speed short routes
D
An aircraft may need to dump fuel. To ensure that the total fuel supply si not dumped -
a. manual shut-off of fuel when enough has been dumped
b. automatic shut-off of fuel when a preset amount has been dumped
c. use of standpipes ni the fuel dumping system
d. use of a timer controlled cut-off switch
C
A turbofan produces less thrust at take-off than a similar size turboprop because -
a. the turboprop is very efficient at modestly accelerating a large mass of air
b. the propeller blades can ‘bite’ the air faster
c. the fan is experiencing Mach Number interference at take-off rpm
d. a turbofan cannot be run at ful thrust at take-off because of noise considerations
A
With a constant speed turboprop engine, power output si controlled by fuel flow. The pilot controls this by -
a. control of the fuel flow control unit
b. control of the propeller blade angle
c. control of the constant speed unit
d. direct control of the air:fuel ratio
A
The primary engine power gauge of a turboprop si the -
a. fuel flow indicator
b. engine temperature gauge
c. torque gauge
d. EPR gauge
C
One reason why jet aircraft use kerosene and not AVGAS is that kerosene has -
a. higher flashpoint
b. less calorific value
c. less viscosity
d. less chemical instability
A
An APU of a B767 maybe operated -
a. in flight only
b. on the ground only
c. whenever ti is required
d. anytime, but only if monitored by an on board flight crew member
C
The purpose of the fuel system filter bypass ni a gas turbine engine is -
a. to save wear on the filter when the fuel is warm
b. to ensure fuel flow even though the filter is blocked
c. to maintain a constant pressure differential
d. to recirculate the fuel
B
If a turbojet thrust reverser unlocked light comes on during flight -
a. the situation is not potentially serious, keep an eye on it
b. the situation is potentially serious, be prepared to reduce thrust if the lever comes up
c. the situation is not serious as it is impossible for a reverser to deploy in flight
d. the situation is potentially critical, shut down the engine if yaw, loss of airspeed or buffet is detected
D
The main reason for stating an upper limit to fuel temperature is -
a. to allow the greatest temperature rise through the engine
b. to ensure the fuel lubricant properties are maintained
c. to stop chemical breakdown of the fuel
d. to ensure vapour release (vapour lock) does not occur
D
An APU auto-shutdown wil not be caused by -
a. overspeed
b. underspeed
c. low oil pressure
d. fire
B
The document ni which you would find the optional fuels approved for a particular aircraft is -
a. in the CARs
b. in ERSA
c. in the aircraft flight manual
d. in the company policy document
C
The additives normally found ni F35 jet fuel (Jet A-1) used ni Australia is -
a. anti-boil
b. no additives normally
c. anti-ice
d. anti-bacterial
B
The engine instrument which would not be found on a turbofan aircraft is -
a. oil pressure
b. N1
c. torque
d. fuel flow
C
An APU does not directly provide -
a. shaft power to drive an electric generator
b. hydraulic pressure
c. bleed air for air conditioning
d. bleed air for pneumatics
B
The inflight problem a turbine engine with low flight idling RPM may have si -
a. excessive turbine temperature on climb and ni cruise
b. flame out on descent
c. excessively rapid acceleration
d. maximum RPM may not be available
B
Adesirable quality of jet fuel is -
a. high viscosity
b. lubricant properties
c. lowest possible calorific
d. value low flash point
B
Ari turbine starters for gas turbine engines normally -
a. cannot be used fi the APU or another engine or compressed air source is not available
b. have a cockpit light to warn of low air pressure
c. are used on small turbine engines
d. can be used to supply the pneumatic system
A
The safeguards used to prevent inadvertent engine thrust reverser deployment ni flight are -
a. thorough crew training
b. an autostow mechanism and mechanical and electrical interlocks and isolation valves which prevent ful reverse thrust unless the thrust levers are at idle and the reversers are fuly deployed
c. hydraulic pressure required to activate deployment
d. guarded buttons
B
In a gas turbine engine with a free power turbine -
a. the free power turbine shaft is independent of the other engine spools
b. the free power turbine drives the compressor
c. a free power turbine wheel is independent of all other turbine wheels
d. the free power turbine is driven by the compressor
A
The advantages of an axial flow compressor compared to a centrifugal flow compressor of the same frontal area in a gas turbine engine are -
a. higher pressure ratios and greater mass airflow
b. ruggedness and compactness
c. high resistance to FOD (foreign object damage)
d. higher SFC (specific fuel consumption)
A
A torque meter in a turboprop aircraft is required for the operation of the -
a. auto feather system
b. beta range
c. pitch lock
d. propeller governor
A
A transport jet aircraft is filled to maximum fuel by volume (full tanks) with kerosene of a low specific gravity. Compared to using kerosene fuel with a higher specific gravity, the maximum range of the aircraft with the low SG kerosene will be -
a. reduced
b. increased
c. unaffected
A
Concerning the connection of turbines and compressors ni a gas turbine engine -
a. the LP compressor is connected to the HP compressor
b. the LP compressor is connected to the HP turbine
c. the LP compressor is connected to the LP turbine
d. the HP compressor is connected to the LP turbine
C
Regarding the measurement of temperature ni a gas turbine engine -
a. EGT measures turbine entry gas temperature
b. TOT measures combustion chamber gas temperature
c. JPT measures jet pipe gas temperature
d. ITT measures compressor outlet temperature
C
With regard to thermal ice protection systems using engine bleed air -
a. when used on an engine intake, thermal ice protection should be regarded as a de- icing system
b. thermal ice protection is only available while taxiing
c. thermal ice protection si only available ni flight
d. when used on an engine intake, thermal ice protection should be regarded as an anti-icing system
D
One of the limitations of an air starting system on gas turbine engines is -
a. the requirement for an APU, another engine or a ground unit to provide compressed air
b. the possibility of thermal runaway
c. the low engine rpm achieved with air starts
d. the limited air supply available
A
The purpose of a propeller brake on a turbo-prop aircraft is -
a. to prevent the propeller windmilling when the engine is shut down and to allow the engine to be run at idle power on the ground without turning the propeller
b. to stop the propeler from turning backwards folowing an in-flight shutdown
c. to slow the aircraft on descent
d. to allow low rpm operation for parking manoeuvres
A
The function of a safety couple in a turboprop engine is -
a. to disconnect the propeller from the gearbox in the event of an engine overspeed
b. to ensure correct re-assembly of the turbine following overhaul
c. to allow reverse pitch during ground operations
d. to decouple the engine from the gearbox in the event of a propeller overspeed
D
The function of a negative torque system (NTS) in a turboprop is to -
a. disconnect the propeller from the gearbox ni the event of an engine overspeed
b. increase the propeller blade angle to prevent the turbine from being driven by the propeller
c. prevent the propeller from reversing its direction of rotation
d. stop the pilot not flying (PNF) from accidentally feathering the engines ni flight
B
The EPR gauge ni a jet aircraft measures:
a. the pressure increase through the engine
b. the pressure ratio between the exhaust air and intake (ambient) air
c. the pressure ratio between the compressor and the combustion chamber
d. the torque on the main drive shaft
B
The Ni gauge indicate in a turbofan engine indicates -
a. fan RPM
b. high pressure compressor temperature
c. turbine speed
d. turbine temperature
A
As a turbofan powered aircraft climbs through the tropopause, thrust wil -
a. increase
b. remain constant
c. reduce at the same rate as below the tropopause
d. reduce at a greater rate compared to below the tropopause
D
The use of bleed air from a gas turbine engine for various services wil result ni most loss of performance during -
a. start and taxi
b. take-off, climb and cruise
c. climb, cruise and descent
d. take-off and climb
D
In a turboprop installation, the term ‘powerplant’ refers to -
a. the compressor, combustion chamber and turbine
b. the gas turbine engine, gearbox and propeller
c. the gas turbine engine and gearbox
d. the propeller and gearbox
B
The reverse thrust system on a turbojet aircraft has interlocks to prevent -
a. full reverse thrust from being applied at low speed
b. full reverse thrust until the reversers are in the full reverse position
c. the propeller from going into negative pitch
d. the fan from reversing direction inflight
B
With reference to a gas turbine engine -
a. TIT is the temperature of the gas between the high pressure and low pressure compressor
b. EGT si the temperature of the gas entering the turbine
c. JPT is the temperature of the gas exiting the combustion chamber
d. TGT is the temperature of the gas between the turbine stages
e. N2 is the temperature of the gas at the front of the high pressure compressor
D
A B727 is maintaining a constant flight level and the TAS is increased from 180 kt to 460 kt. Thrust available at maximum thrust wil -
a. increase
b. decrease
c. decrease then increase
d. increase then decrease
e. remain constan
C
The fuel flow transmitter ni the fuel system of a large jet transport category aircraft is located -
a. at the inlet to the high pressure pump
b. at the outlet from the high pressure pump
c. at the inlet to the fuel control unit
d. at the outlet from the fuel control unit
D
Turbojet engine compressor blade angle of attack si primarily determined by -
a. inlet air temperature and exhaust gas temperature
b. inlet air pressure and exhaust gas pressure
c. inlet air velocity and exhaust gas velocity
d. engine RPM and TAS
D
As the thrust levers of a turbojet engined aircraft are advanced for takeoff -
a. airflow increases, causing a higher fuel flow and RPM
b. fuel flow increases, causing a higher EGT and increased RPM
c. EGT increases, causing a higher mass airflow and increased fuel flow
d. thrust increases, causing increased exhaust gas velocity
B
The pressure rise in the centrifugal compressor of a gas turbine engine occurs in -
a. the impeller only
b. the diffuser only
c. both the impeler and the diffuser
d. the stator vanes
C
Gas turbine engine compressor blades do not usually require thermal anti-ice (TAI) protection because -
a. the temperature rise through the compressor raises the temperature above freezing
b. the centrifugal action of the rotor blades prevents ice accretions
c. the high pressures prevent ice formation
d. the nose cone prevents ice formation ni the rest of the compressor
B
On a wet day takeoff ni a jet engined aircraft, the igniter plugs may be selected to continuous ignition. In this case the characteristics of the spark wil be -
a. high value (joules) at low voltage to prevent overheating the nozzle guide vanes
b. low value (joules) at high voltage to preserve the igniter plugs and the ignition unit
c. high value (joules) at high voltage ot ensure a fast relight in the event of a flame out
d. low value (joules) at low voltage to conserve battery power
B
With an air turbine starter system on a large modern jet engine, the starter si disengaged -
a. automatically by the trip spring after a pre-set time period
b. automatically by the starter clutch at a predetermined RPM
c. manually by the starter control solenoid at a suitable idle RPM
d. manually by the disengage switch when the peak TOT has been reached
B
The primary purpose of the APU ni a large jet transport category aircraft is for -
a. in flight engine starting
b. electrical and pneumatic supply on the ground
c. in flight electrical supply
d. in flight pneumatic supply
B
The design feature which si not an advantage of the annular combustion chamber design ni a modern gas turbine engine, compared ot other multi-chamber designs is -
a. improved combustion efficiency
b. less cooling air required
c. elimination of flame propagation problems between chambers
d. reduced weight and cost
e. compact
f. greater structural integrity
F
A particular turbine fuel has aspecific gravity of 0.80 at agiven temperature. A temperature rise of 20°C wil result ni a calorific (energy) value for the fuel which is -
a. the same energy value as for the original temperature per litre of fuel
b. the same energy value as for the original temperature per kg of fuel
c. less energy than for the original temperature per kg of fuel
d. more energy than for the original temperature per kg of fuel
e. more energy than for the original temperature per litre of fuel
B
The function of the torque meter ni a turboprop powered aircraft is to -
a. brake the propeller
b. feather the propeller
c. lock the propeller at the fine pitch lock
d. monitor shaft output power
D
A probable result of a hot start in a gas turbine engine is -
a. stable turbine temperatures
b. torching of the exhaust section
c. excessive compressor temperatures
d. excessive turbine RPM
B
Regarding the measurement of temperature ni a gas turbine engine -
a. EGT measures turbine entry gas temperature
b. TOT measures combustion chamber gas temperature
c. JPT measures jet pipe gas temperature
d. ITT measures compressor outlet temperature
C
The ram air effect on a turbojet engine results ni a conversion of -
a. pressure energy in the airstream into heat
b. velocity of the airstream into kinetic energy
c. the kinetic energy ni the airstream into pressure
d. heat energy ni the airstream into velocity
C
Boost pumps ni the fuel system of a large jet transport category aircraft are generally -
a. piston type
b. variable displacement type
c. gear type or impeler type
d. plunger type
C
Regarding the functioning of the reverse thrust system on a high by pass turbo fan engine -
a. blocker doors are used to reverse the hot stream
b. clamshells or buckets are used to reverse the cold stream
c. target deflectors are used ot divert the cold stream
d. blocker doors are used to divert the cold stream
D
The takeoff run of a turbofan powered aircraft wil be increased by -
a. increased density
b. low altitude
c. low temperature
d. increased altitude
D
The use of bleed air on takeoff ni a large turbojet engined aircraft wil result ni a -
a. lower EGT
b. higher EGT
c. increased RPM and surging d. decreased RPM and surging
B
The effect of a change in temperature on the specific gravity of AVTUR is -
a. variations ni temperature have no effect on the specific gravity
b. specific gravity increases as temperature increases
c. specific gravity decreases as temperature increases
C
The ideal air:fuel ratio for a turbine engine is -
a. 5:1
b. 15:1
c. 25:1
d. 35:1
e. 45:1
B
The section of the APU which supplies compressed air to start the main engines on a large jet transport aircraft is -
a. the compressor
b. the diffuser inlet
c. the turbine
d. the exhaust
A
The purpose of the air shroud on an atomiser type (duplex) fuel spray nozzle in the combustion chamber of a gas turbine engine is -
a. to diffuse the fuel and give a more even spray pattern
b. to reduce carbon deposits around the nozzle tip and cool the nozzle
c. to impart a swirl to the fuel and reduce axial velocity
d. to slow the air down as it enters the combustion chamber
B
The function of variable inlet guide vanes ni a gas turbine engine is -
a. to prevent compressor blade stall when the engine is operating at low RPM
b. to straighten the airflow entering the compressor at high RPM
c. to reduce the axial velocity of the airflow entering the compressor
d. to reduce compressor back pressure at design RPM
A
The gas turbine engine component which acts to straighten the airflow before exiting the engine is -
a. the nozzle guide vanes
b. the last stage turbine blades c. the exhaust cone
d. the rear turbine exhaust cone support struts in the jet pipe
D
Turbofans and turbojets are preferred over turboprops for speeds over about 350 kt because -
a. turboprops have reduced propulsive efficiency at high speeds
b. turboprops are considered too noisy at high speeds
c. turboprops cannot carry as much payload as turbojets at high speed
d. turboprops are not as aesthetically pleasing as turbofans ni flight
A
Reverse thrust on a turbofan or turbojet is not as effective as forwards thrust because -
a. engine RPM is limited during reverse thrust operation
b. the angle of the reverse thrust is not directly opposing the aircraft motion
c. hot or turbulent air may be blown into the engine intake reducing power output
d. the airspeed is less than when thrust is directed ni the normal direction
B
The most common method of ice protection used on the propellers of turboprop aircraft is -
a. thermal pneumatic
b. pneumatic boots
c. de-icing fluid
d. electrical
D
The following statements correctly lists the differences between kerosene and wide cut type aviation turbine fuel -
a. kerosene is the British name and wide cut is the American name for the same fuel
b. kerosene has a lower flashpoint than wide cut fuel
c. kerosene has a lower boiling point than wide cut fuel
d. kerosene has a lower volatility than wide cut fuel
D
The most common type of starter motor found on large modern jet transport category aircraft turbine engines is -
a. gas turbine starters
b. electric starters
c. air turbine starters
d. cartridge starters
C
The effect on the maximum static thrust output of a turbojet engine at Mean Sea Level with changes in ambient temperature and pressure is -
a. static thrust increases with an increase in temperature and pressure
b. static thrust decreases with an increase in temperature and pressure
c. static thrust decreases with a decrease in temperature and increased pressure
d. static thrust decreases with an increase in temperature and decreased pressure
D
The function of bleed valves in the compressor of a gas turbine engine is -
a. to increase the mass airflow over the early compressor stages at low engine RPM
b. to increase the mass airflow over the rear compressor stages at low engine RPM
c. to increase the mass airflow over the early compressor stages at high engine RPM
d. to increase the mass airflow over the rear compressor stages at high engine RPM
A
The changes in the gas flow within the combustion chamber of a gas turbine engine are -
a. volume increases, temperature increases, pressure decreases or remains constant
b. velocity decreases, temperature decreases, pressure increases or remains constant
c. volume decreases, temperature increases, pressure decreases
d. velocity decreases, temperature increases, pressure increases
A
Air in the combustion chamber of a gas turbine engine is slowed to -
a. provide better mixtures for combustion
b. reduce possibility of flame out
c. contain the flame in a smaller area
d. keep the combustion chamber walls cool
B
Turbine fuel requires -
a. high viscosity
b. high calorific value
c. high compressibility
d. low chemical stability
B
A particular turbofan engine has 3 shafts. N1 refers to -
a. the fastest shaft
b. the slowest shaft
c. the compressor shaft
d. the shortest shaft
B
An advantage of the centrifugal flow compressor over the axial flow compressor is -
a. it is more efficient over a larger range of compression ratios
b. for a given power output, it uses less fuel
c. it is cheaper and more robust
d. it is more demanding in its operating technique
C
Asymptom of a ‘hung’ start with a gas turbine engine si -
a. falling engine temperature
b. starter motor disengagement
c. no rise in RPM
d. increasing fuel flow
C
Operating ajet engine at design rpm wil give the -
a. greatest fuel burn per hour
b. greatest SFC
c. minimum SFC
d. minimum fuel burn per hour
C
Jet engine design RPM is -
a. maximum rpm
b. slightly in excess of maximum RPM
c. slightly less than maximum RPM
d. about 80% maximum RPM
C
With regard to transport category aircraft fuel systems, the true statement is true -
a. fuel gauges provide the only method of accurately determining fuel on board before commencing a flight
b. measurement of fuel quantity on board may only be conducted on a level surface
c. fuel on board may be determined by use of readings from dipsticks combined with tables and a sight gauge to correct for uneven terrain
d. fuel used meters are the only reliable method of accurately determining fuel on board before commencing a flight
C
The purpose standpipes serve in an aircraft fuel system is -
a. they allow quick and accurate determination of fuel tank contents
b. they prevent unintentional dumping of the entire fuel tank contents
c. they provide easy transfer of fuel between tanks
d. they give constant information about relative fuel levels in different tanks
B
The ideal air:fuel mixture ratio for kerosene is -
a. 5:1
b. 15:1
c. 50:1
d. 130:1
B
The component of a gas turbine engine which directs the airflow into the compressor is -
a. the stator vanes
b. the nozzle guide vanes
c. the diffuser
d. the inlet guide vanes
D
The function of Interconnectors between multiple combustion chambers in a gas turbine engine is to -
a. equalise operating pressure and allow combustion propagation between chambers
b. equalise operating temperature and allow combustion propagation between chambers
c. equalise mass flow velocity and prevent flame propagation between chambers
d. equalise mass flow density and allow flame propagation between chambers
A
When climbing at a constant Mach number the Calibrated Airspeed (CAS) wil -
a. decrease if the temperature decreases
b. decrease
c. decrease if the temperature increases
d. increase
e. remain constant
B
When climbing at a constant Mach number the True Airspeed (TAS) wil -
a. decrease if the temperature decreases
b. decrease
c. decrease if the temperature increases
d. increase
e. remain constant
A
The difference between leading edge slats and leading edge flaps is -
a. they are two names for the same device
b. slats reenergise the boundary layer and flaps alter the effective camber of the leading edge
c. flaps reenergise the boundary layer and slats alter the effective camber of the leading edge
d. flaps decrease the stall speed while slats increase the stall speed
B
As an aircraft climbs above FL300, the IAS and EAS stall speeds wil -
a.IAS and EAS stall speeds both increase -
b. IAS stall speed increases and EAS stal speed remains the same
c. EAS stal speed increases and IAS stall speed remains the same
d. IAS and EAS stall speeds both decrease
A
As an aircraft accelerates from subsonic speeds through 1.00M to supersonic speeds, the coefficient of (CD) wil -
a. increase
b. decrease
c. increase then decrease
d. decrease then increase
e. remain constant
C
In a constant Mach number climb in the isothermal layer above the tropopause, TAS wil -
a. decrease due to decreasing pressure
b. increase due to decreasing pressure
c. remain constant due to the constant temperature
d. remain constant due to the constant Mach number
C
In a constant Mach number climb in the isothermal layer above the tropopause, TAS wil -
a. decrease due to decreasing pressure
b. increase due to decreasing pressure
c. remain constant due to the constant temperature
d. remain constant due to the constant Mach number
A
McRIT is -
a. that speed where al of the local airflow is supersonic
b. that speed where al of the local airflow is subsonic
c. that speed above which supersonic local airflow first occurs
d. none of the above
C
The variable most directly affecting the speed of sound si
a. density
b. pressure
c. altitude
d. temperature
D
An aircraft exceeds its McriT. Assuming no ‘Mach Trimmer’ is fitted, the first thing to occur would be -
a. nose pitch up
b. severe vibration, buffet and structural failure
c. compressor stall
d. nose pitch down
D
For high subsonic cruise speeds, the reason it si best to delay the formation of wing shockwaves is -
a. to minimise the noise being made by the aircraft
b. to keep the drag penalty ot a minimum
c. so that Mach trimmers are not required
d. to stop tailplane vibration
B
Fast transport aircraft may have a supercritical wing section. This is to -
a. give maximum lift at low speed
b. give minimum lift at high speed
c. reduce the top wing surface acceleration
d. reduce the bottom wing surface acceleration
C
Aileron control reversal can be caused by -
a. the wing twisting about its lateral axis due to high aerodynamic loads at high speed
b. the aileron twisting about its longitudinal axis under heavy manoeuvring
c. excessive drag on aileron movement up
d. excessive drag on aileron movement down
A
Exceeding Mcrit results in a nose down pitch by the aircraft. This si because -
a. the CP moves rearward
b. the CP moves forward
c. the tailplane is producing excessive drag
d. none of the above
A
An aircraft si slowly accelerating through its Merit ot transonic cruise. The Coefficient of Lift -
a. will decrease and then increase
b. will increase and then decrease
c. keeps increasing
d. keeps decreasing
B
A Mach Trimmer -
a. trims the aircraft for a nominated Mach number
b. stops the aircraft exceeding its Mcrit
c. ensures that with increasing speed the aircraft wil tend ot pitch down
d. ensures that with increasing speed the aircraft wil tend ot pitch up
D
At transonic speeds, the reason some aircraft use spoilers for rol control even though they have ailerons fitted is -
a. to save wear on the ailerons
b. to prevent aileron lockout
c. to prevent shockwave formation
d. to overcome loss of aileron effectiveness due to flow separation ahead of the aileron
D
Ayaw damper -
a. overrides rudder input in turbulence
b. is disabled below FL200
c. minimises the need for rudder control inputs at high altitude and high Mach number
d. is only engaged when the autopilot si engaged
C
Wing sweep results in an increase ni the stalling angle of attack. This si because -
a. the swept wing si more efficient at low speeds
b. the swept wing is less efficient at high speeds
c. swept wing CL is less than straight wing CL for any given body angle
d. swept wing CL is more than straight wing CL for any given body angle
C
Wing sweep an important feature for high speed flight because -
a. it allows for effectively shorter wings and so less induced drag occurs
b it increases lift at high altitudes
c. it delays the drag effects of shockwaves
d. wing area is larger and the load more evenly spread
C
On swept wing aircraft, nose pitch up at the stall si caused by -
a. sudden slat retraction
b. elevator stall combined with a rearward C of G movement
c. wing tip stall and the effective CP moving rearwards
d. wing tip stall and the effective CP moving forwards
D
Most swept wing aircraft are fitted with a stickpusher because -
a. it assists the pilot with a positive landing
b. a positive initiation of descent is often an ATC requirement
c. it will counter the natural nose down pitch of a swept wing aircraft entering a stall
d. the combination of wing design and powered controls does not provide adequate stall protection and recovery may be very difficult or impossible in some cases
D
Jet aircraft maximum rate of climb (Vy) is determined by -
a. total thrust over weight
b. total drag over thrust
c. excess power over weight
d. excess thrust over drag
C
Vs when related to transport category aircraft is -
a. the minimum steady flight speed
b. the speed at which the aircraft stalls
c. the sinking speed
d. any defined speed above the sinking speed
A
You want your jet aircraft to stay airborne as long as possible. You would achieve this by flying -
a. at the appropriate holding speed at any level
b. at an altitude where use of engine design RPM would result in a speed of Vimd
c. as high as possible at a speed of 1.32 Vimd
d. as low as possible at aspeed of Vimd
B
To achieve maximum angle of climb, you would climb at -
a. Vmo using maximum cruise power
b. Vs using maximum climb power
c. VREF using maximum rated thrust
d. Vimd using maximum thrust
D
Large jet aircraft have a large speed band where the rate of climb is fairly constant. This is because -
a. the excess power means that drag is largely irrelevant
b. for this band, the power available and power required curves are nearly parallel
c. drag is small compared with thrust and doesn’t vary with speed
d. this is a design feature to assist ATC with aircraft positioning
B
VA is the -
a. IAS for a particular body angle
b. velocity for a nominated attitude
c. manoeuvring speed
d. limiting load speed
C
The Centre of Pressure (CP) of a transport aircraft wing should ideally have minimal movement with variations in aircraft speed because -
a. excessive changes ni the CP can lead to structural fatigue ni the airframe
b. large trim changes would be needed with large CP movement
c. the C of G can go outside defined limits with large CP movement
d. autopilots cannot cope with the changing control forces with a moving CP
B
You have descended and have to hold at 3000 feet. At this altitude, your ideal holding speed would primarily be determined by -
a. engine RPM considerations
b. IAS considerations
c. flap extension limits
d. body angle limits
B
Considering that flap extension increases lift, they not used for the climb because -
a. too much lift would be produced
b. not enough lift would be produced
c. minimum drag speed si higher with flap up and the extra drag cancels the lift benefit
d. climbing IAS si ni excess of flap limiting speed
C
Swept wing aircraft employ a ‘stall identification alarm system’ (stick pusher). This operates at -
a. 1.3 Vs
b. 10 kt above stalling speed
c. the speed below which controlled level flight is not sustainable
d. 15 degrees angle of attack
C
Jet aircraft overspeed warnings wil operate -
a. at Vmo/Mmo
b. slightly above Vmo/Mmo
c. slightly below Vmo/Mmo
d. slightly below Vdf/Mdf
B
Vmo/Mmo is -
a. recommended climb/descent speed
b. the maximum operating speed at which an aircraft may be intentionally flown
c. the greatest speed at the an aircraft may be economicaly flown
d. a compromise speed between efficiency and airframe fatigue considerations
B
Mfs (free stream) si -
a. the average Mach No of air passing the aircraft
b. the maximum Mach No of air passing the aircraft
c. the actual Mach No of the aircraft through the air
d. the minimum Mach No of air passing the aircraft
C
