問題一覧
1
Which of the following could cause damage to the nose ceramic or to the electrode of an aircraft spark plug?
Improper gapping procedure.
2
The purpose of a safety gap in a magneto is to
Protect the high-voltage winding from damage.
3
Capacitance afterfiring in most modern spark plugs is reduced by the use of
A built-in resistor in each plug.
4
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
5
The amount of voltage generated in any magneto secondary coil is determined by the number of windings and by the
Rate of collapse
6
Airflow to the pneumatic starter from a ground unit is normally prevented from causing starter overspeed during engine start by
Activation of a flyweight cutout switch.
7
Which of the following, obtained during magneto check at 1,700 RPM, indicates a short (grounded) circuit between the right magneto primary and the ignition switch?
BOTH — 1,700 RPM, R — 0 RPM, L — 1,700 RPM, OFF— 0 RPM.
8
What is the approximate position of the rotating magnet in a high-tension magneto when the points first close?
Full register
9
Shielding is used on spark plug and ignition wires to
Prevent interference with radio reception.
10
Igniter plugs used in turbine engines have a long service life because they
Do not require continuous operation.
11
Alignment of the marks provided for internal timing of a magneto indicates that the
Magneto is in E-gap position.
12
If new breaker points are installed in a magneto on an engine, it will be necessary to time the
Magneto internally and the magneto to the engine.
13
What component of a dual magneto is shared by both ignition systems?
Rotating magnet
14
The spark is produced in a magneto ignition system when the breaker points are
Beginning to open
15
When using a timing light to time a magneto to an aircraft engine, the magneto switch should be placed in the
BOTH position
16
Defective spark plugs will cause the engine to run rough
At all speeds
17
What will be the effect if the spark plugs are gapped too wide?
Hard starting
18
When testing a magneto distributor block for electrical leakage, which of the following pieces of test equipment should be used?
A high-tension harness tester.
19
Which of the following would be cause for rejection of a spark plug?
Insulator tip cracked.
20
What should be used to clean grease or carbon tracks from capacitors or coils that are used in magnetos?
Acetone
21
A clicking sound heard at engine coast-down in a pneumatic starter incorporating a sprag clutch ratchet assembly is an indication of
The pawls re-contacting and riding on the ratchet gear.
22
Advantages of dual ignition in aircraft engines include providing a backup magneto system, increasing the output power of the engine, and
Increasing the output power of the engine.
23
The electrical circuit from the spark plug back to the magneto is completed by grounding through the
Engine structure
24
If the ground wire of a magneto is disconnected at the ignition switch, the result will be the
Engine will not stop running when the ignition switch is turned off.
25
Upon inspection of the spark plugs in an aircraft engine, the plugs were found caked with a heavy black soot. This indicates
A rich mixture.
26
Is A safety feature usually employed in direct-cranking starters
c. Stator nozzle design that choke airflow and stabilize turbine wheel spee.
27
when does the ignition event take place?
Before the piston reaches TDC on compression stroke.
28
What likely effect would a cracked distributor rotor have on a magneto?
a. Ground the secondary circuit through the crack.
29
Sharp bends should be avoided in ignition leads primarily because
a. Weak points may develop in the insulation through which high tension current can leak.
30
Using a cold spark plug in a high-compression aircraft engine would probably result in
b. Normal operation
31
The purpose of an under current relay in a starter-generator system is to
b. Disconnect power from the starter-generator and ignition when sufficient engine speed is reached.
32
How does high-tension ignition shielding tend to reduce radio interference?
Receives and grounds high-frequency waves coming from the magneto and high-tension ignition leads.
33
Ignition check during engine run-up indicates a slow drop in RPM. This is usually caused by
Incorrect ignition timing or valve adjustment.
34
The secondary coil of a magneto is grounded through the
a. Primary coil
35
When installing a magneto on an engine, the
Piston in the No. 1 cylinder must be a prescribed number of degrees before top center on the compression stroke.
36
Which of the following will have the lowest RPM at any given engine speed?
b. Distributors
37
A defective primary capacitor in a magneto is indicated by
b. Burned and pitted breaker points.
38
When the ignition switch of a single (reciprocating)
The primary circuits of both magnetos are grounded.
39
The capacitor-type ignition system is used almost universally on turbine engines
a. High-heat intensity
40
What test instrument could be used to test an ignition harness for suspected leakage?
c. A high tension lead testar.
41
The greatest density of flux lines in the magnetic circuit of a rotating magnet-type magneto occurs when the magnet is in what position?
c. Full alignment with the field shoe faces.
42
Failure of an engine to cease firing after turning the magneto switch off is an indication of
b. An open P-lead to ground.
43
In a turbine engine dc capacitor discharge ignition system, where are the high-voltage pulses formed?
b. At the triggering transformer.
44
Ignition check during engine run-up indicates excessive RPM drop during operation on the right magneto.
Faulty or fouled spark plugs.
45
When internally timing a magneto, the breaker points begin to open when the rotating magnet is
c. A few degrees past the neutral position.
46
How is the strength of a magneto magnet checked?
a. Hold the points open and check the output of the primary coil with an ac ammeter while operating the magneto at a specified speed.
47
When will the voltage in the secondary winding of a magneto, installed on a normally operating engine, be at its highest value?
c. Just prior to spark plug firing.
48
What components make up the magnetic system of a magneto?
c. Rotating magnet, the pole shoes, the pole shoe extensions, and the coil core.
49
Magneto timing drift is caused by erosion of the breaker points and
a. Wear of the cam followers.
50
What would be the result if a magneto breaker point mainspring did not have sufficient tension?
The points will float or bounce.
51
Magneto breaker point opening relative to the position of the rotating magnet and distributor rotor (internal timing) can be set most accurately
b. During assembly of the magneto before installation on the engine.
52
(1) The platinum and iridium ground electrodes used on fine wire spark plugs are extremely brittle and can be broken if they are improperly handled or adjusted. (2) When gapping massive-electrode spark plugs, a wire gauge should be inserted between the center and ground electrodes while moving the ground electrode in order to avoid setting the gap too close.
Only No.1 is true.
53
Magneto pole shoes are generally made of
Laminations of high-grade soft iron.
54
What will be the result of using too hot a spark plug?
a. Preignition
55
Hot spark plugs are generally used in aircraft powerplants
c. With comparatively low operating temperatures.
56
In an aircraft ignition system, one of the functions of the capacitor is to
Facilitate a more rapid collapse of the magnetic field in the primary coil.
57
Inspection of pneumatic starters by maintenance technicians usually includes checking the
Oil level and magnetic drain plug condition.
58
If a spark plug lead becomes grounded, the
Magneto will not be affected.
59
Which of the following statements regarding magneto switch circuits is NOT true?
a. In the BOTH position, the right and left magneto circuits are grounded.
60
The spark occurs at the spark plug when the ignition's
c. Primary circuit is broken.
61
Spark plug fouling caused by lead deposits occurs most often
a. When cylinder head temperatures are relatively low.
62
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
b. The 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.
63
What is the electrical location of the primary capacitor in a high-tension magneto?
c. In parallel with the breaker points.
64
The numbers appearing on the ignition distributor block indicate the
Sparking order of the distributor.
65
When performing a magneto ground check on an engine, correct operation is indicated by
A slight drop in RPM.
66
used on most turbine aircraft engines is
Capacitor discharge
67
If it is found that a shielded ignition system does not adequately reduce ignition noise, it may be necessary to install
A filter between the magneto and magneto switch.
68
In a typical starter-generator system, under which of the following starting circumstances may it be necessary to use the start stop button?
Hung start
69
A spark plug is fouled when
Its spark grounds without jumping electrodes.
70
When internally timing a magneto, the breaker points begin to open whenWhen internally timing a magneto, the breaker points begin to open when
The magnet poles are a few degrees beyond the neutral position.
71
The magnetic circuit of a magneto consists of a permanent multi-pole rotating magnet. The core is made of
Soft iron
72
What is the purpose of a safety gap in some magnetos?
To discharge the secondary coil's voltage if an open occurs in the secondary circuit.
73
What is the radial location of the two north poles of a four-pole rotating magnet in a high-tension magneto?
180° apart
74
Magneto breaker points must be timed to open when the
Greatest magnetic field stress exists in the magnetic circuit.
75
What are two parts of a distributor in an aircraft engine ignition system? 1. Coil 2. Block 3. Stator 4. Rotor 5. Transformer
2 and 4