Ignition and Starting Systems Part 2 Flashcards
Sharp bends should be avoided in ignition leads primarily because
weak points may develop in the insulation through which high tension current can leak.
How are most radial engine spark plug wires connected to the distributor block?
By use of cable piercing screws.
Hot spark plugs are generally used in aircraft powerplants
with comparatively low operating temperatures.
In the event a pneumatic start valve will not operate and the manual override must be used, the starter T-handle must be closed at schedule starter drop out because
the starter will overspeed at a given N2
When the switch is off in a battery ignition system, the primary circuit is
opened.
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 igniter lead is disconnected from the plug and the center electrode grounded to the engine after disconnecting the transformer-exciter input and waiting the prescribed time.
When does battery current flow through the primary circuit of a battery ignition coil?
When the breaker points are closed and the ignition switch is on.
Which of the following breaker point characteristics is associated with a faulty capacitor?
Coarse grained.
What likely effect would a cracked distributor rotor have on a magneto?
Ground the secondary circuit through the crack.
When using an electric starter motor, the current flow through it
is highest at the start of motor rotation.
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.
The constrained gap igniter plug used in some gas turbine engines operates at a cooler temperature because
the construction is such that the spark occurs beyond the face of the combustion chamber liner.
When using a timing light to time a magneto to an aircraft engine, the magneto switch should be placed in the
BOTH position.
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.
A spark plug is fouled when
its spark grounds without jumping electrodes.
How does high tension ignition shielding tend to reduce radio interference?
Reduces Leakage.
The purpose of a safety gap in a magneto is to
protect the high voltage winding from damage.
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.
When the ignition switch of a single (reciprocating) engine aircraft is turned to the OFF position,
the primary circuits of both magnetos are grounded.
The spark is produced in a magneto ignition system when the breaker points are
beginning to open.
Which of the following statements most accurately describes spark plug heat range?
A cold plug is designed so that the insulator tip is reasonably short to hasten the rate of heat transfer from the tip through the spark plug shell to the cylinder head.
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.
Spark plugs are considered worn out when the
electrodes have worn away to about one-half of their original dimensions.
Shielding is used on spark plug and ignition wires to
prevent interference with radio reception.
Which of the following are distinct circuits of a high tension magneto?
Magnetic, primary, and secondary.
(Refer to Figure 5.) Which malfunctions will allow the igniters to operate when tested but be inoperative during a start attempt?
Wire 10 is broken and/or the ignition relay is inoperative.
How many secondary coils are required in a low tension system on a 18 cylinder engine?
36
The type of ignition system used on most turbine aircraft engines is
capacitor discharge.
If the 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.
