15 cad－vin

APU auto stutdown.....? a. generator overload, EGT over-limit b. CIT FCU inoperative c. crew control

A

Bell-mouth a. very good aerodynamic b. .... suspect "vane..... effect" c. retractable screen

A

During igniter plug maintenance, check for: a. Damage, security or leakage b. sign of chafy, security or fluid contamination c. sign of burn , security or gas leakage.

A

Engine inlet icing, primary indication? a. EGT increase b. EGT decrease c. compressor surge

A

For turboshaft engine, helicopter with a free turbine can rotate at its own speed is because of: a. gas coupled b. mechanically coupled c. governed

A

Impractical for fuel a. avoid freezing in any condition b. able to lubricate parts c.

A

Reaction gear a. epcyclic b. bevel c. differential

A

Use of water injection a. over come ambient temperature b. dirty compressor

A

afterburner will increase the air mass flow and: a. jet pipe termperature b. compressor RPM c. compressor ratio

A

allowable turbine blade damage is: a. leading trailing edge of the blade accordance to MM limit b. slight pitting c. not allow

A

control cable friction end used to? a. stop control cable at one selected position when engine is removed b. for auto adjusting the throttle level c. cannot move from selected position

A

critical repair area of compressor blade a. root b. tip c. chord

A

engine mount a. allow expansion axial and radially b. underslung if turbo prop c. axial if turbojet

A

evidence of compressor surge a. TGT increase, significant engine vibration b. TGT increase, EPR increase c.

A

excessive oil leakage a. air seal failure b. overtemperature of oil c. ...

A

flame tube n combustion chamber: a. used to confine and steady the flame b. lowers the working temperature c. ensure complete combustion of kerosene

A

how to increase fuel effieiency: a. higher TIT temperature limit b. lower TIT temperature limit c. use combustor material for turbine

A

labyrinth seal not very effective at a. low air pressure b. low temperature c. high air pressure

A

low pressure fuel pump? a. pressurize fuel before HP fuel pump b. back up fuel pump if HP failure

A

more fuel added after Mach 1 gas velocity is reached a. engine speed increase, tail pipe pressure increase b. mass flow decrease, tail pipe pressure increase c. mass flow increase, engine speed decrease

A

multi-tube exhaust reduces noise by: a. air mixing, intensive wake b. large diameter for suppressor c. increase the low frequency and reduce the high frequency noise

A

open circuit on limit power resistor in the engine starter: a. .....immediate maximum speed b. no change c. delay response on starting

A

philosophy of dual channel a. instant changeover if active failure b. both controlling c. ..... allow engine stop when one failure

A

potential energy to kinetic energy in combustion chamber? a. additional to fuel b. compression of air c. slowing down the air

A

tachometer generator is: a. independently from an aircraft electrical system b. 28V D.C. c. 115V A.C.

A

thermocouple leads a. cannot be shorten because it's circuit b. heat lagged material between thermocouple to indicator

A

total pressure as inlet air, the pressure is? a. increase ram air b. decrease ram air c. forward direction of air flow

A

turbine blade under fixed stress, service life is: a. deteriorate significantly when operated slightly over temperature b dependent on blade cooling only c. deteriorate significantly when operated slightly over speed

A

turboprop turbine experience overspeed, N2 governor will a. decrease fuel flow at FCU b. cut fuel supply c. bleed compressor air

A

vane type fuel flow meter theory: a. spring restricted move magnet b. vane coupled by tachometer c. vane coupled with AC generator

A

water-injection, what to do with the remaining water after the system activated? a. drain overboard after the system has turned off b. all consumed c. remain in the tank for further use

A

what is the affect of carbon formation on the combustion chamber nozzle? a. change the flame/fuel ejection angle b. create turbulence in the combustion chamber c. no effect on performance

A

what type of combustion chamber utilize flame tube a. can-annular b. annular c. multiple-can

A

whch statement about water-injection is correct? a. water for cooling, alcohol for anti-icing b. alchol for cooling, water for increasing the mass flow rate c. alcohol for cooling, water for increasing the thrust power

A

for engine storage what desiccants is requirement to add into engine? a. silica gel b. anti-freeze fluid c. kerosone

A desiccant = 乾燥劑

growth of turbine due to high rotation speed a. can be limited by outer shroud b. c.

A he shroud acts to prevent blade-tip losses and excessive vibration. Distortion under high loads, which tend to twist the blade toward low pitch, is also reduced.

engine start sequence: a. start off, ignition, sustain speed b. high pressure fuel on, light up, ignition off c. starter, idle speed, peak starting temperature

A starter on igniter on fuel starter off igniter off idle

air speed increase, SFC increase, which type of engine a. turbojet b. turboprop c. both

A turboprop: engine combination gives the best specific fuel consumption(SFC) of any gas turbine engine over a speed range of 300 to 400 miles per hour.

compared to aviation gasoline, turbine fuel is different as it contains. a. kerosene b. colour for fuel distinguish c. lead

A why not B: turbine fuel colourless.

spalling cause a. separation of metal by flaking or chipping b. surface crack c. inclusion when a load put on the surface

A A rough broken area on the surface of a material. Usually caused because of surface cracks or inclusions when a load is put on the surface. Refer to diagram.

APU as a service provider, the user: a. pneumatic: water tank pressurization, engine start b. electrical: ACM, cabin lighting, equipment cooling c. hydraulic: ...

A The APU compressor discharges air into a plenum chamber which is connected, via ducting, to the air conditioning system and the main-engine air-starting system of the aircraft.

kinetic valve eroded is indicated by: a. a rapid rise of exhaust gas temperature b. amount of soft iron is found in SOAP sample c. excess smoke at jet tail pipe

A erode:The flow of fluids or gases cause the material to wear; heat or grit makes this occur more quickly.

one compressor stage include a. a rotor followed by a stator b. a stator followed by a stator c. a rotor

A, rotor first

EPR just above 1 when engine shutdown a. it is normal b. it is out of tolerance, need to adjust c. need to replace the gauge

B

EPR when stationary a. 0 b. 1 c. 1.5

B

Experience N2 decrease, boro-scope expect to find: a. b. N2 blade damage c. High spot on NGV

B

HP filter a. upstream of oil cooler b. downstream of oil cooler c. upstream if wing booster pump

B

afterburner installed in the turbine engine will increase: a. air mass flow and RPM b. exhaust velocity and thrust c. air mass flow and EPR

B

air is extracted from compressor section, the power a. goes up b. goes down c. unchange

B

altitude increase with fixed throttle a. EPR goes up b. EPR goes down c. EPR unchanged

B

anti-ice...... compressor blade: a. always anti-icing b. never anti-icing c. anti-icing depends on power setting

B

compressor blade and casing material respectively a. aluminium alloy and magnesium alloy b. titanium alloy and aluminium alloy c. magnesium alloy and aluminium alloy

B

fire detector sensor, temperature setting: a. set during transit check b. sealed set by manufacturer, and cannot be changed c. set during maintenance

B

flame propagation tube is used in what combustion chamber? a. can type b. can-annular c. annular

B

for turbo-prop turbine, which statement is correct? a. govered b. no mechanical connection between the compressor and power shaft c. compressor and power shaft is mechanical connected

B

higher exhaust speed: a. exhaust cone b. tail pipe c. exhaust strut

B

hollow inlet guide vane hollow reason a. less weight b. allow bleed air in for anti-ice c. to circulate lubricates oil

B

how the fuel flow tramsmitter makes sure the drum rotates at the same direction? a. restraining spring b. swirl generator c. turbine

B

how to operate fire bottle: a. manually discharge by valve b. electrically cartilage fire to ruypt pin to cylinder head c. electrically operate valve to discharge fire extinguish element to engine

B

kinetic energy to propulsive energy ratio is? a. kinetic efficiency b. propulsive efficiency c. thermal efficiency

B

measuring the engine oil temperature at? a. within oil tank b. measuring at the point where oil flow into bearing compartment c. measuring at the point where oil flow out bearing compartment

B

moveable tail moves towards the turbine outlet, it will change? a. nozzle area b. exhaust velocity c. chocked limit

B

nozzle guide vane cooling type a. transpiration b. film c. convection

B

propeller RPM lower than engine, how to achieve: a. free turbine b. through planetary reduction gearbox c. direct couple with gas generator

B

propeller governer flyweight influenced by centrifugal force but controlled by a. propeller RPM b. speeder spring pressure c. fuel pressue

B

pull of fire handle implement a. mechanical and linkage b. electrically with aircraft battery c. discharge automatically when electrical power cut-off

B

removing engines, be caution at? a. wing tip and tail in case touching ground b. tailstand requirement vary with the aircraft type and number of engines c. tail stand is an optional tool

B

resistor in resistor spark plug a. ensure high enough voltage in circuit then discharge b. prevent electric corrosion by limiting the peak current c. prevent radio interference

B

swirl vane in combustion chamber? a. increase air flow b. better air mix and retain combustion c. slow down air

B

tertiary creep: a.low temp b.over temp + high rotational speed c. long operation speed

B

the HP shaft is overspeed: a. initiate fire extinguish system b. reduce the fuel flow rate c. immediately cut off the fuel flow

B

thermocouple connected in a. series b. parallel c. network

B

turbofan engine with a mixed exhaust, the T/R system has a. one T/R for cold stream, one T/R for hot stream b. one T/R for both cold and hot stream c. both T/R for cold and hot stream

B

turboprop, detector vane is deployed: a. enhance more air intake during take-off condition b. block ice, sand etc for prevent FOD c. bypass the remain to the compressor

B

two type of turbo-prop a. b. single shaft, free turbine c. double spool, free turbine

B

what is hung start a. the engine cannot light-up b. the engine light-up, but cannot accelerate c. normal start

B

when aircraft is flying at high altitude, the fuel control unit: a. increase the fuel rate when the increase amount of air intake b. reduce the fuel flow rate c. no change in fuel flow rate

B

which combustion system has the highest efficiency? a. can-annular b. annular c. multiple can

B

which statement is correct about turbine section cooling? a. diaphragm require more cooling than rim b. rim is hooter than centre c. drum disc is hotter than centre

B

Kerosene is more difficult in visual inspection on the contamination of water than gasoline because a. Kerosene's SG is far from water b. Kerosene's SG is close to water c. Kerosene's colour is close to water

B SG of Kerosene: 0.820 SG of Gasoline: 0.730 SG of water: 1

swirl vane: a. propagate the flame between the combustion areas b. keep the flame off the liner c. increase axial velocity, though out mix fuel and air

B liner = flame tube why not C: it cannot increase axial velocity

the gross thrust of an engine is rated 2000lb, the aircraft is flying at 500ft/sec, and the thrust is? a. more than the gross thrust b. less than the gross thrust c. no change

B p.s. gross thrust - momentum drag = net thrust

what shape of the stator vane when installed before impulse type rotor blade? a. straight b. convergent c. divergent

B p.s. question does not mention compressor or turbine stage

any given turbo-engine, jet velocity increase: a. overall efficiency increase b. propulsion efficiency decrease c. thrust efficiency decrease

B propulsive efficiency = work done on aircraft/energy imported to engine airflow

compressor stall: a. front of compressor b. rear of compressor c. combustion chamber

B surge: when all stage stall stall: rear of compressor in my opinion: suddenly cross wind, the front of compressor will stall as well

combustion chamber outer-casting: a. al alloy b. nimonic c. magnesium alloy

B nimonic is an alloy of Nickel Chromium; highly heat-resisting material

axial-flow compressor compared to centrifugal compressor: a. more robust b. light weight c. shorter shaft and fewer compent

B, lighter weight per thrust why not A: robust is an advantage of centrifugal compressor

Dry motor with pneumatic start a. continuous operate with enough pneumatic b. .....lower operation pressure to continuous operate c. limited cycle with MM

C

During transit check a. engine oil level, thrust reverser door movement, T/R door b. starter oil level..... c. Servicing the CSD, filling oil

C

EEC in conjunction with? a. fuel pressure(or fuel flow) b. hydro-mechanic c. FADEC

C

Epicyclic gear is used between shaft a. rotate in right angle b. rotate in same plate c. rotate about same axis

C

Fire detection wire installed with rubber plastic clip: a. resistance insulation of the wire b. prevent corrosion with the engine support c. reduce heat exchange and protect the wire from sharp clip

C

NOT correct for engine inlet a. decrease aerodynamic drags b. decrease air speed c. increase air speed for easy compression

C

Oil pressure pump: a. b. gear pump and helical c. piston and gear pump

C

When pressure testing a rigid fuel tank for leakage, it would use a pressure of a. 1 psi of air b. 5 psi of nitrogen c. 10 psi of nitrogen

C

blocker door types thrust reverser components a. hydraulic motor, screwjack b. hydraulic actor, screwjack, gearbox c. air motor, screwjack, gearbox

C

compressor surge is caused by: a. air flow velocity higher than relative engine RPM b. airflow velocity lower than relative engine RPM c. air separate from blade surface

C

gas turbine engine take-off with humid weather. a. loss of thrust b. increase of thrust c. no noticeable effect compare to piston engine counter part

C

high humidity a. take off thrust decrease b. take off thrust penalize because of incorrect fuel to air ratio c. no significant change

C

highest velocity in engine: a. compressor outlet b. combustion chamber outlet c. nozzle guide vane outlet

C

in a free turbine engine a. the air to compressor inlet from turbine b. the compressor and the power output shaft is mechanically connected c. the compressor and the output shaft is not mechanically connected

C

modern variable exhaust a. open wide when minimum thrust setting b. small opening when at idle c. area change for supersonic flight

C

on a gas turbine engine D.C. starting circuit, if there is an open circuit on the contact of overspeed relay. a. starter motor will stop only when starter switch is off b. starter motor will continuous to run 30s and then stop c. no power support is connected to starter motor

C

parallel nozzle guide vane a. impulse-reaction b. impulse c. reaction

C

reduce exhaust nozzle area: a. affect exhaust pressure b. affect exhaust temperature c. affect exhaust speed

C

spark plug installed with too little torque a. not install deep enough to ignite fuel mixture b. vibration damage the thread of container and plug c. gas leakage and damage container and plug

C

thernocouple maximum operating temperature: a. 400C b. 850C c. 1100C

C

thrust reverser opened, EPR? a. less than 1 b. negative c. not in use/not applicable

C

thrust reverser warning light on a. locked b. unlocked c. transion

C

toroidal vortex is describing in fuel system? a. vortex formation on wing tip b. fuel spray nozzle spraying pattern c. the recircling station fluid inside combustion chamber

C

turbine oil a. low flash point b. affect thermosetting plastic c. dermatitis when long exposure

C

turboprop governor adjust when a. in flight b. no need c. at install

C

water used in water-injection system is? a. distilled water b. tap water c. de-mineralized water

C distilled water = 蒸餾水 tap water = 自來水 de-mineralized water = 去離子水

air tapped from the L.P. compressor is used for a. anti-icing b. cool the combustion chamber c. heat the wing leading edge

C from H.P. compressor for anti-icing from L.P. compressor for heat wing leading edge

a ratio-meter circuit is used for engine temperature measurement. if the ratio-meter sizes an off-scale high reading, then a. the sensor has a short circuit. b. the sensing bulb is out of calibration. c. there is an open circuit in the balancing coil.

C open circuit = high resistant high resistant = high reading

when an engine is transported as a wind milling-engine on the specific pod on a transport aircraft. a. the oil and fuel system must be drained. b. drain fuel system c. add engine oil to a specific quantity.

C To supply the oil pressure to feather a propeller, a separate electric pump is often incorporated into the pitch change hydraulic system. P

too little fuel at start up a. hot start b. cold start c. hung start

C Hung start usually occurs just after starter cutout and are primarily due to lean fuel scheduling. Insufficient starter torque and lean fuel scheduling will cause slow acceleration below starter cutout and engine may not even reach self-sustaining speed.

engine ground testing: a. move throttle smooth to test acceleration and deceleration capabilities b. outside temperature irrelevant c. facing the wind

C The aircraft should be positioned facing into wind so that the engine intakes and exhausts are over firm concrete with the jet efflux directed away from other aircraft and buildings.

cartridge type starter consists of a. small turbine blow with high pressure gas b. high torque DC motor c. impulse turbine blow with high speed air

C The starter motor is basically a small impulse- type turbine that is driven by high velocity gases from a burning cartridge.

gas generator of turbo-shaft engine: a. b. compressor, compressor turbine, power turbine c. compressor, combustion chamber, compressor turbine

C The term gas producer or gas generator is used to denote the parts of the engine that provide the high velocity gases which will drive the propeller. The items that make up the gas producer include the: 􏰀 engine compressor, 􏰀 combustion chambers, 􏰀 compressor turbine.

centrifugal breather is used to a. b. to prevent cavitation in the centrifugal pump c. to prevent oil loss in the pressure breather pump

C To separate the air from the oil returning to the tank, a de- aerating device and a centrifugal breather are incorporated.

For electrical mounted on metal, electrical de-icing is operated: a. cyclic at a rate when air velocity is increased b. continually c. cyclic at a rate when air temperature is decreased.

C urbo-propeller engines use electrical power or a combination of electrical power and hot air.

turbine disk definition

anchoring component for turbine blades bolted or welded to main shaft

take-off wet thrust definition

during take-off, time limited wet thrust: afterburner being used dry thrust after NOT in used

Pre-swirl vanes vanes

promote through mixing of air fuel slow pond axial velocity.

dynamic horse power defintion

...

overapeed limit pointer a. indicate speed (RPM) above normal remains until reset by indicator reset switch

...

SFC definition

(number of pound of fuel / hour) / (pound of net thrust) specific fuel consumption

HP fuel cock position

...