Quiz
Ignition and Starting Systems
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Perguntas do quiz (40)
1Why are high-tension ignition cables frequently routed from the distributors to the spark plugs in flexible metallic conduits?
- ATo eliminate high altitude flashover.
- BTo reduce the formation of corona and nitric oxide on the cable insulation.
- CTo reduce the effect of the high-frequency electromagnetic waves emanated during operation.
2In an aircraft ignition system, one of the functions of the capacitor is to
- Aregulate the flow of current between the primary and secondary coil.
- Bfacilitate a more rapid collapse of the magnetic field in the primary coil.
- Cstop the flow of magnetic lines of force when the points open.
3When the switch is off in a battery ignition systems, the primary circuit is
- Agrounded.
- Bopened.
- Cshorted.
4The purpose of staggered ignition is to compensate for
- Ashort ignition harness.
- Brich/fuel air mixture around exhaust valve.
- Cdiluted fuel/air mixture around exhaust valve.
5What is the difference between a low-tension and high-tension engine ignition system?
- AA low-tension system produces relatively low voltage at the spark plug as compared to a high-tension system.
- BA high-tension system is designed for high altitude aircraft, while a low-tension system is for low-to medium-altitude aircraft.
- CA low tension system uses a transformed coil near the spark plugs to boost voltage, while the high-tension system voltage is constant from the magneto to the spark plugs.
6What test instrument could be used to test an ignition harness for suspected leakage?
- AA high tension lead tester.
- BA high voltage DC voltmeter.
- CA high amperage DC ammeter.
7The capacitor-type ignition system is used almost universally on turbine engines primarily because of its high voltage and
- Alow amperage.
- Blong life.
- Chigh-heat intensity.
8How does the ignition system of a gas turbine engine differ from that of a reciprocating engine?
- AOne igniter plug is used in each combustion chamber.
- BMagneto-to-engine timing is not critical.
- CA high-energy spark is required for ignition.
9In a turbine engine DC capacitor discharge ignition system, where are the high-voltage pulses formed?
- AAt the breaker.
- BAt the triggering transformer.
- CAt the rectifier.
10Why are turbine engine igniters less susceptible to fouling than reciprocating engines spark plugs?
- AThe high-intensity spark cleans the igniter.
- BThe frequency of the spark is less for igniters.
- CTurbine igniters operate at cooler temperatures.
11The constrained-gap igniter plug used in some gas turbine engines operates at cooler temperature because
- Ait projects into the combustion chamber.
- Bthe applied voltage is less.
- Cthe construction is such that the spark occurs beyond the face of the combustion chamber liner.
12Generally, when removing a turbine engine igniter plug, in order to eliminate the possibility of the technician receiving a lethal shock, the ignition switch is turned off and
- Adisconnected from the power supply circuit.
- Bthe igniter lead is disconnected from the plug and the center electrode grounded to the engine after disconnecting the transformer-exciter input lead and waiting the prescribed time.
- Cthe transformer-exciter input lead is disconnected and the center electrode grounded after disconnecting the igniter lead from the plug and waiting the prescribed time.
13Great caution should be exercised in handling damaged hermetically sealed turbine engine igniter transformer units because
- Acompounds in the unit may become a fire or explosion hazard when exposed to the air.
- Bsome contain radioactive material.
- Csome contain toxic chemicals.
14Igniter plugs are subjected to high intensity spark discharges and yet they have a long service life because they
- Aoperate at much lower temperatures.
- Bare not placed directly into the combustion chamber.
- Cdo not require continuous operation.
15Sharp bends should be avoided in ignition leads primarily because
- Aweak points may develop in the insulation through which high tension current can leak.
- Bignition lead wire conductor material is brittle and may break.
- Cignition lead shielding effectiveness will be reduced.
16Which statement is correct regarding the ignition system of a turbine engine?
- AThe system is normally de-energized as soon as the engine starts.
- BIt is energized during the starting and warmup periods only.
- CThe system generally includes a polar inductor-type magneto.
17The type of ignition system used on most turbine aircraft engines is
- Ahigh resistance.
- Blow tension.
- Ccapacitor discharge.
18Ignition check during engine runup indicates a slow drop in RPM. This is usually caused by
- Adefective spark plugs.
- Ba defective high-tension lead.
- Cincorrect ignition timing or valve adjustment.
19How does high-tension ignition shielding tend to reduce radio interference?
- APrevents ignition flashover at high altitudes.
- BReduces voltage drop in the transmission of high-tension current.
- CReceives and grounds high-frequency waves coming from the magneto and high-tension ignition leads.
20Why do turbine engine ignition systems require high energy?
- ATo ignite the fuel under conditions of high altitude and high temperatures.
- BBecause the applied voltage is much greater.
- CTo ignite the fuel under conditions of high altitude and low temperatures.
21Which of the following are included in a typical turbine engine ignition system?
- ATwo igniter plugs.
- BTwo transformers.
- COne exciter unit.
- DTwo intermediate ignition leads.
- ETwo low tension igniter leads.
- FTwo high tension igniter leads.
22(Refer to figure 5.) With power applied to the bus bar, what wire supplies standby power to the starter relay contact?
- A4.
- B7.
- C8.
23(Refer to figure 5.) With power applied to the bus bar, what switch changes will allow the ignition exciters test switch to function?
- AEngine master switch, battery switch, and power lever switch.
- BEngine master switch, start switch, and test switch.
- CEngine master switch and ignition switch.
24(Refer to figure 5.) The type of system depicted is capable of operating with
- Aexternal power only.
- Beither battery or external power.
- Cbattery power and external power simultaneously.
25(Refer to figure 5.) If wire No. 8 is broken or disconnected after start rotation is initiated, and the power lever is advanced, the
- Astarting sequence will continue normally.
- Bstarter will shut down, but the igniters will continue to fire.
- Cstarting sequence will discontinue.
26(Refer to figure 5.) When an external power source is connected to the aircraft
- Athe battery cannot be connected to the bus.
- Bboth battery power and external power are available to the bus.
- Cthe starter relay coil has a path to the ground.
27The purpose of an under current relay in a starter-generator system is to
- Aprovide a backup for the starter relay.
- Bdisconnect power from the starter-generator and ignition when sufficient engine speed is reached.
- Ckeep current flow to the starter-generator under the circuit capacity maximum.
28In a typical starter-generator system, under which of the following starting circumstances may it be necessary to use the start stop switch?
- AHung start.
- BHot start.
- CContacts stick open.
29(Refer to figure 5.) Which malfunctions will allow the igniters to operate hen tested but be inoperative during a starting attempt?
- AConductor No. 10 broken.
- BConductor No. 11 broken.
- CIgnition relay inoperative.
- DConductor No. 12 broken.
30(Refer to figure 5.) Which malfunctions will allow the igniters to operate normally during start but be inoperative when tested?
- AConductor No. 14 broken.
- BConductor No. 10 broken.
- CConductor No. 15 broken.
- DConductor No. 12 broken.
31When using an electric starter motor, current usage
- Ais highest at the start of motor rotation.
- Bremains relatively constant throughout the starting cycle.
- Cis highest just before starter cutoff (at highest RPM).
32When using an electric starter motor, the current flow through it
- Ais highest just before starter cutoff (at highest RPM).
- Bremains relatively constant throughout the starting cycle.
- Cis highest at the start of motor rotation.
33The primary advantage of pneumatic (air turbine) starters over comparable electric starters for turbine engines is
- Aa decreased fire hazard.
- Breduction gearing not required.
- Chigh power-to-weight ratio.
34A clicking sound heard at engine coast-down in a pneumatic starter incorporating a sprag clutch ratchet assembly is an indication of
- Agear tooth and/or pawl damage.
- Bone or more broken pawl springs.
- Cthe pawls recontacting and riding on the ratchet gear.
35Pneumatic starters are usually designed with what types of airflow impingement systems?
- ARadial inward flow turbine and axial-flow turbine.
- BCentrifugal compressor and axial-flow compressor.
- CDouble entry centrifugal outward flow and axial-flow turbines.
36Inspection of pneumatic starters by maintenance technicians usually includes checking the
- Aoil level and magnetic drain plug condition.
- Bstator and rotor blades for FOD.
- Crotor alignment.
37Air turbine starters are generally designed so that reduction gear stress or damage may be detected by
- Acharacteristic sounds from the starter assembly during engine start.
- Bbreakage of a shear section on the starter drive shaft.
- Cinspection of a magnetic chip detector.
38Airflow to the pneumatic starter from a ground unit is normally prevented from causing starter overspeed during engine start by
- Astator nozzle design that chokes airflow and stabilizes turbine wheel speed.
- Bactivation of a flyweight cutout switch.
- Ca preset timed cutoff of the airflow at the source.
39A safety feature usually employed in pneumatic starters that is used if the clutch does not release from the engine drive at the proper time during start is
- Aflyweight cutout switch.
- Bspring coupling release.
- Cdrive shaft shear point.
40A safety feature usually employed in direct-cranking starters that is used to prevent the starter from reaching burst speed is the
- Adrive shaft shear point.
- Bstator nozzle design that chokes airflow and stabilizes turbine wheel speed.
- Cspring coupling release.
Informações
- Descrição
- 12 Shop (Powerplant) Quiz sobre Ignition and Starting Systems, criado por jocelyn2145 em 07-11-2015.
- Autor
- jocelyn2145
- Idioma
- English
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- 57
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