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1D

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1
A battery operated ignition system needs to be supplemented by a generator
  • To facilitate continuous ignition during take-off in bad weather
  • Only on engines where a high energy ignition system is used
  • All of the time so that the generator takes over if battery supply fails
2
A clicking sound heard at engine coast-down in a pneumatic starter incorporating a sprag clutch ratchet assemblyis an indication of
  • One or more broken pawl springs.
  • Gear tooth and/or pawl damage.
  • The pawls re-contacting and riding on the ratchet gear.
3
A DC starter motor disconnects due to
  • Current decreasing switching off an overspeed relay
  • Current increasing switching off an overspeed relay
  • A centrifugal switch that acts like an overspeed relay
4
A dry motor cycle would be required to
  • Clear the engine after a wet start
  • Check the operation of the igniters
  • Check engine run down time
5
A gas turbine engine normaly has provisions for what total number of igniter plugs in the combustio chamber
  • Three
  • One
  • Two
6
A glow plug may be used in place of a spark plug on
  • Large engines
  • Small engines
  • Low tempreature engines
7
A glow plug operates
  • Manually
  • Electrically
  • By heat action
8
A HEIU is rated in
  • Amps
  • Joules
  • Watts
9
A high energy ignition system can have two output valves, what are these values
  • Low value for normal starting and starting in adverse weather conditions, high value for relight
  • Low value for normal starting, high value for relight and starting in adverse weather conditions
  • Low value for continuous ignition in bad weather conditions, high value for normal starting and relight
10
A high tension booster coil supplies a high tension
  • Current to supplement an inadequate current of the primary circuit at low speeds
  • Voltage direct to the rotor arm retarded electrode
  • Current direct to the sparking plug
11
A hot start is associated with
  • High N1 speed
  • High EGT
  • Surplus / excess fuel supply
12
A hung start will be indicated by
  • Engine fails to light up
  • EGT exceeding limits
  • RPM lower than self sustaining speed
13
A magneto impulse coupling provides
  • A retarded spark for idling and an advanced spark for higher rev/min
  • A means of adjusting the magneto internal timing
  • A stronger retarded spark for starting
14
A 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 the
  • Drive shaft shear point
  • Spring coupling release
  • Flyweight cutout switch
15
A safety feature usually employed in pneumatic starters that is used to prevent the starter from reaching burst speen if inlet air does not terminate on schedule is the
  • Drive shaft shear point
  • Starter nozzle design that chokes airflow and stabilizes the turbine wheel speed
  • Spring coupling release
16
A starter has two holes
  • To check level of oil
  • For the breather sump vent
  • For alignment
17
A starter is designed to rotate the engine to
  • Idle speed
  • Ignition and light off speed
  • Above self sustained speed
18
A starter-generator is not usually fitted to a piston engine aircraft because
  • Piston pwered aircraft use a D.C. system and a starter-generator is an A.C. machine
  • It is too expensive and heavy to install on a light aircraft
  • A starter-generator cannot provide full electrics at low RPM
19
After an unsuccessful start of an engine
  • Unburnt fuel can be evacuated by motoring the engine with HP cock closed
  • The engine has to be left for some time before another start
  • Unburnt fuel can be drained from fuel drainage lines
20
Air turbine starters are generally designed so that reduction gear distress or damage may be detected by
  • Characteristic sounds from the starter assembly during engine start
  • Inspection of a magnetic chip detector
  • Breakage of a shear section on the starter drive shaft
21
Airflow to the pneumatic starter from a ground unit is normally prevented from causing starter overspeed during engine start by
  • Starter nozzle design that chokes airflow and stabilizes turbine wheel speed
  • A preset timed cutoff of the airflow at the source
  • Activation of a flyweight cutout switch
22
An adavantage of a gas turbine starter is
  • It does not require external connections
  • It provides high power for low weight
  • It uses a low volatile fuel
23
An aircraft flying through heavy rain may use, as a precaution
  • Engine indicating deicing
  • Airframe deicing
  • Continuous ignition
24
An electrical starter-generator is
  • Series wound with high torque
  • Series wound with low torque
  • Shunt wound with high torque
25
An HEIU works by
  • The AC busbar
  • A discharging capacitor
  • A contact breaker
26
An impulse starter is a device to assist in starting an engine which uses
  • An explosive inserted in a special tube
  • A special starting battery which provides a sudden impulse of electricity to the plugs
  • A coil spring to increase momentarily the speed of rotation of the magneto
27
As engine speed increases the position of the igniton spark is
  • Not altered
  • Retarded
  • Advanced
28
Burned magneto points are caused by
  • A faulty distributor
  • A faulty capacitor
  • A fault in the ignition harness causing the spark to occur internally
29
During normal running of a gas turbine engine
  • Combustion is continuously supported by ignition
  • Combustion is self supporting
  • Combustion is intermittently supported by ignition
30
During the start cycle of a low bypass or turbo-shaft engine
  • Light up occurs at 10%-12% max RPM, starters cut out at 50%-55% max RPM and idle is at 50%-55% max RPM
  • Light up occurs at 15%-18% max RPM, starters cut out at 35%-40% max RPM and idle is at 50%-65% max RPM
  • Light up occurs at 12%-15% max RPM, starters cut out at 25%-30% max RPM and idle is at 50%-55% max RPM
31
For starting the engine, the HP cock should be initially
  • In a position which depends on the fuel system
  • Closed
  • Open
32
Generally, 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
  • The transformer exciter input lead is disconnected and the centre electrode grounded to the engine after disconnecting the igniter lead from the plug and waiting the prescribed time
  • Disconnected from the power supply circuit
  • The igniter lead is disconnected from the plug and the centre electrode grounded to the engine after disconnecting the transformer-exciter input lead and waiting the prescribed time
33
Great caution should be exercised in handling damaged hermetically sealed turbine engine igniter transformer units because
  • Compounds in the unit may become a fire or explosion hazard when exposed to the air
  • Some contain radioactive material
  • Some contain toxic chemicals
34
HEIU ignitor plugs receive their electrical supply from
  • Discharge inductor
  • Discharge capacitor
  • Starter system electrical circuit
35
High energy ignition is required because of the
  • High flash point of fuel
  • Absorbed moisture content
  • Low flash point of fuel
36
How does the ignition system of a gas turbine engine differ from that of a reciprocating engine
  • Magneto to engine timing is not critical
  • A high energy spark is required for ignition
  • One igniter plug is used in each combustion chamber
37
If a magneto becomes earthed
  • The magneto will cut out
  • The engine will operate as normal
  • The switch will fail to stop the engine
38
If the engine fail to light-up, the starter cycle is cancelled by
  • A time switch
  • A centrifugal switch
  • A low pressure relay
39
Igniter plugs used in turbine engines are subjected to high intensity spark discharges and yet they have a long service life because they
  • Are not placed directly into the combustion chamber
  • Operate at much lower temperatures
  • Do not require continuos operation
40
Ignition harnesses have ridgid out conduits
  • To reduce radio interference and prevent damage
  • To prevent damage
  • To reduce radio interferance
41
Ignitor plugs are cleaned by
  • Steel wool
  • Compressed air and brushing softly with soft brush
  • Light sand blasting
42
In a gas turbine engine DC capacitor discharge ignition system, where are the high voltage pulses formed
  • At the breaker
  • At the triggering transformer
  • At the rectifier
43
In an electrical starting system, the slow start resistor is short circuited by the
  • Centrifugal switch
  • Time switch
  • Overspeed switch
44
In the H.E.I.U the choke
  • Protects the unit from excessive high voltage
  • Prolongs the discharge
  • Prolongs the life of the plug
45
In the H.E.I.U the discharge resistors
  • Allow the capacitors to discharge when the unit is switched off
  • Protects the unit from excessive voltages
  • Allow sufficient voltage to be stored to provide relight facilities up to 55,000 ft
46
Inspection of the pneumatic starters by maintenance technicians usually includes checking the
  • Stator and rotor blades for FOD
  • Oil level and magnetic drain plug condition
  • Rotor alignment
47
Is it safe to touch the output from one ignition excitor 10 minutes after switching off the system
  • Yes, even if there is voltage at the output, without power input power this is not dangerous
  • Yes, I can be sure that there is no longer any voltage at the output
  • No, even after hours there can be a dangerous voltage at the output
48
Magnetos should be checked at slow running to ensure that
  • The control of the ignition system is correct before an ignition check is carried out at high power
  • Both sparking plugs are functioning correctly in individual cylinders
  • The magneto drop is not excessive at both low and high rev/min
49
On a gas turbine engine DC starting circuit, if there is an open circuit on the contact of the over speed relay
  • No power supply is connected to the starter motor
  • Starter motor will continue to run for 30 sec and then stop
  • Starter motor will stop only when starter switch selected off
50
On a low energy dual ignition system, if a relight is necessary
  • The pilot selects both ignitors
  • The pilot selects one of the two ignitors
  • It occurs automatically
51
On light up, the gas tempreature will
  • Rise rapidly
  • Rise slowly
  • Rise rapidly, then fall as RPM increases to idle
52
Pneautmatic starters are usually designed with what types of airflow impingement systems
  • Double entry centrifugal outward flow and axial-flow turbines
  • Centrifugal compressor and axial-flow compressor
  • Radial inward flow turbine and axial-flow turbine
53
Prior to turning the propellor you must
  • Ensure the mag switches are off
  • Ensure the plugs are earthed
  • Ensure the magnetos are armed
54
Self sustaining RPM means that
  • The engine will run independently of external help
  • There is sufficient power for ground maneuvering
  • The engine can accelerate to full power in under 5 seconds
55
Self sustaining speed is
  • The RPM at which the engine continues without external assistance
  • V1 Speed
  • Take off velocity
56
Sparks from a magneto in a confined structure cause what problem
  • Open circuit in the LT coil
  • Flashover
  • Open circuits in the HT coil
57
The engine is checked for a dead cut at slow running
  • To check ignition at high and low engine revolutions
  • To check the operation of both plugs in the cylinder
  • To check the ignition system before tests at higher engine revolutions
58
The engine is checked for dead cut at
  • Slow running
  • Full throttle
  • Cruising RPM
59
The field of the D.C. starter motor used on gas turbine engine is
  • Series only
  • Shunt or compound
  • Series or compound
60
The magneto of an engine fitted with a constant speed propeller should be checked
  • In fully fine pitch
  • While propeller in constant speeding
  • In full coarse pitch
61
The magnetos
  • Provide power for the aircraft electrical system
  • Provide power to charge the batteries
  • Provide the high voltage for spark plugs
62
The primary advantage of pneumatic starters over comparable electric starters for turbine engines is
  • High power to weight ratio
  • A decreased fire hazard
  • Reduction gearing not required
63
The purpose of a condenser as fitted in a magneto is to
  • Delay the rapid break down of the primary current and prevent arcing at the points
  • Assist in the rapid break down of the primary current and prevent arcing at the contact breaker points
  • Reduce the high tension voltage of the secondary circuit
64
The purpose of an under current relay in a starter-generator system is to
  • Disconnect power from the starter-generator and ignition when sufficient engine speed is reached
  • Provide a back up for the starter relay
  • Keep the current flow to the starter-generator under the circuit capacity maximum
65
The resistor in a D.C. starter motor
  • Prevents over speed
  • Prevents current surge when motor is at low RPM
  • Used when D.C. motor fails
66
The spark in the HE igniter is supplied by
  • A capacitor
  • The AC busbar
  • A contact circuit breaker
67
The spark plug is usually fitted into
  • The cylinder head
  • The crank case
  • The cylinder wall
68
The starter light is on during a start cycle (Low voltage electrical starter)
  • If the light stays on after 30 seconds action is required
  • This is normal for as long as the starter switch is on, take no action
  • Indicates electrical power is flowing to the starter
69
The starter light remains on after engine start. This indicates
  • There is still power being supplied to the starter motor
  • No problem as this is normal
  • The starter motor is still engaged and the engine must be stopped and the cause investigated
70
The supply in a magneto is transformed from low to high tension by
  • A magnetized rotor turning between magnetized pole pieces
  • The rapid reversal of the field in the primary winding reacting with the secondary windings
  • The turning of the distributor arm causing rapid decay
71
The type of ignition system used on most turbine aircraft engines is
  • High resistance
  • Capacitor discharge
  • Low tension
72
To avoid a lethal electric shock from the ignition system, which of the following components must be grounded before maintenace work
  • Spark plugs
  • Ignition lead
  • Capacitors
73
The voltage at the igniter plug depends on
  • Voltage at the main AC bus
  • Type of plug
  • Gap in the ignition system box
74
Voltage at the igniter plug is
  • Dependant on the type of plug
  • Governed by the air gap in the HEIU box
  • The same as the main DC bus
75
What is meant by stabilised idle
  • Engine oil pressure remains constant
  • Fuel flow increases steadily
  • EGT value remains constant
76
What is the first engine instrument indication of a successful start of a turbine engine
  • A rise in the exhaust gas temperature
  • A rise in the engine fuel flow
  • A rise in oil pressure
77
What is the purpose of the current limiting resistor in a starter circuit
  • To prevent the starter from over speeding in the final phase of starting
  • To provide overall control of the speed of the starter
  • To prevent an initial current surge
78
What is the purpose of the resistor built into the centre electrode of most spark plugs
  • To minimise wear of the electrode caused by the high voltage spark
  • To minimise the current flow for eack spark
  • To reduce the voltage released by each spark
79
What is the purpose of the wire braid covering HT ignition leads
  • To prevent radio interferance
  • To prevent damage to the leads
  • To ensure no short circuits occur
80
What type of ignition system has been universally accepted for use in a gas turbine engine
  • High capicitor, low spark
  • Low spark, capacitor
  • High energy, capacitor
81
What type of turbine blade is most commonly used in air starter motors
  • Impulse
  • Reaction
  • Impulse-Reaction
82
What will happen if a magneto becomes disconnected from the switch
  • The engine will cut out
  • The switch fails to stop the engine
  • The other magneto will carry the full load
83
When a magneto switch is set to OFF, how is the magneto made safe
  • Earth one end of the circuit
  • Earth both ends of the circuit
  • Mageneto is already safe if its switch is set to OFF
84
When an engine being started by an air starter reaches self sustaining speed
  • The starter valve is closed by the flyweight cut-out switch in the air starter
  • The motor is disconnected by the flyweight cut out switch
  • The motor is diconnected by the pilot
85
When carrying out an ignitor lead insulation check, the minimum reading should be
  • Infinity
  • 0.0001 Ohms
  • 2 Megaohms
86
When is igniton used
  • For relight and start up
  • For continuous relight
  • At high altitudes
87
When might an engine use fine spark plugs rather than massive electrode plugs
  • When engine weight is an issue
  • When plug fouling is an issue
  • When greater power is required
88
When reconnecting the HEIU, which cable must be reconnected first
  • HT before LT
  • LT before HT
  • It makes no difference
89
When using a timing light to test a magneto what does the light illuminating indicate
  • That the points are just closing
  • That the points have closed fully
  • That the points are just opening
90
Which of these situations can activate ignition
  • Outside air temperature below 0'
  • Windshield wiper switched on
  • Engine anti-ice system is switched on
91
Which statement is correct about the two ignitor plugs you can find on each engine
  • Each plug has its own ignition excitor and 1 or 2 plugs work at a time
  • Both plugs are supplied from the same ignition excitor and always work at the same time
  • Both plugs are supplied from one ignition excitor. The second box becomes active if the first box fails
92
Why do turbine engine ignition systems require high energy
  • To ignite the fuel under conditions of high altitude and low temperatures
  • Because the applied voltage is much greater
  • To ignite the fuel under conditions of high altitude amd high temperatures
93
With the magneto switch in the off position the magneto is
  • Open circuit
  • Earthed
  • Closed circuit
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