Marc

What components make up magnetic system of a magneto?

Rotating magnet, the pole shoes, the pole shoe extensions, and the coil core

The greatest density of flux lines in the magnetic circuit of a rotating magnet- type magneto occurs when the magnet is in what position (8506)

Full alignment with the pole shoe faces

A compensated cam is necessary in a radial engine because?

The linkage pins are attached to a master rod. Each piston will reach TDC at a slightly different number of degrees of crankshaft rotation

The purpose of staggered ignition is to compensate for? (8532)

Diluted fuel/air mixture around the exhaust valve

What will be the result of INCREASING the gap of the breaker points in a magneto? (8509)

Advance the spark and decrease its intensity

“Induced voltage, whether caused by self-inductance or mutual inductance, always operates in such a direction as to oppose the source of its creation“

This is the definition of which law?

Lenz’s Law

When a magneto is disassembled, keepers are usually placed across the poles of the rotating magnet to reduce the loss of magnetism, these keepers are usually made of? (8503)

Soft iron

The purpose of a magneto safety gap is to?

Provide a pathway for the secondary coil to discharge if the spark plug fails to fire

In a four pole magneto, installed on a six cylinder engine, opposite poles occur every _______ degrees of magneto rotation

90 degrees

When the switch is in the O F F position in a battery ignition system, the primary circuit is? (8522)

Opened

The principle best describing “E“ gap is always located a few degrees past neutral due to?

Inductance

In a low-tension ignition system?

A. Only a primary coil is located in the magneto

B. The secondary coil is located out on the cylinder

Both A & B are correct “correct answer“

Distributors on high tension magnetos?

A. Connect the high-tension circuit to the proper cylinder

B. Rotates at ½ engine speed

C. Fires in magneto sparking order

D. All the above answers are correct “correct answer”

Magneto points are commonly made of?

Platinum-iridium

With the magneto switch in the LEFT position?

Right magneto “P“ lead is grounded

In an aircraft ignition system, one of the functions of the capacitor is to (8520)

Facilitate a more rapid collapse of the magnetic field in the primary coil

Given a Bendix S4LN-4200 magneto, what would be be a typical breaker point material used during overhaul?

Tungsten

A clicking sound heard at the engine coast-down in a pneumatic starter, incorporating sprag cutch rachet assembly, is an indication of? (8626)

Pawls re-contracting and ridding on the rachet gear

If the P lead is disconnected the magneto will be (8613)

on regardless of ignition switch position

Which of the following are distinct circuits of a high tension magneto (8602)

Magnetic, Primary, and Secondary

Venting prevents moisture from accumulating in the magneto. This prevents a condition called

Flashover

The E gap angle is usually defined as the number of degrees between the neutral position of the rotating magnet and the position (8505)

Where the contact points open

On a D4LN-3200 magneto, how many high-tension leads are used

8

How is the strength of a magneto magnet checked (8504)

Hold the points open and check the output of the primary coil with an AC Ammeter while operating the magneto at a specific speed

The magneto switch in the right magneto position, the left P lead is

Left Mag grounded

When a magneto is operating, what is the most probable cause of a shift in internal timing

The cam follower wear and/or breaker points wear

Which of the following is a cause for rejection of a spark plug (8586)

Insulator tip cracked

Resistor spark plugs help to prevent

Capacitance after firing

A defective primary capacitor in a magneto is indicated by? (8526)

Burned and pitted breaker points

How many secondary coils are required in a low-tension ignition system on a 6 cylinder engine? (8527)

12

When using a timing light to time a magneto to an aircraft engine, the Magneto switch should be placed in the? (8536)

Both position

capacitance after-firing of a spark plug is caused by? (8553)

Stored energy in the ignition shielded lead unloading after the secondary circuit fires

What will be the result of decreasing the hap of the breaker points in a magneto? (8509)

Retard the spark and increase the dwell

Why are high-tension ignition cables frequently routed from the distributers to the spark plugs in flexible metallic conduits

To reduce the effect of the high-frequency electro-magnetic waves emanated during operation

What should be used to clean grease or carbon tracks off capacitors or coils that are used in magnetos? (8558)

Acetone

What is the purpose of the safety gap in some magnetos? (8525)

To discharge the secondary coil’s voltage if an open occurs in the secondary circuit

The test instrument that could be used to test an ignition harness for suspected leakage is? (8538)

A high tension lead tester

What RPM is a reciprocating engine ignition switch check made? (8608)

The slowest speed possible

Which of the following is an advantage of an impulse coupling? (8531)

It accelerates the magnet for increased starting spark

Which of the following statements most accuratley describes spark plug heat range? (8580)

A cold plug is designed so that the insulator tip is reasonably short to hasten the rare of heat transfer from the tip through the spark plug shell to the cylinder head

In an aircraft ignition system, one of the functions of the condenser is to?

Facilitate a more rapid collapse of the magnetic field in the primary coil

Spark plugs are considered worn out when? (8563)

Electrodes are worn to ½ their original dimensions

If staggered ignition timing is used the? (8572)

Spark plug nearest the exhaust valve will fire first

Compensated breaker point cams are used in radial engines because?

The master rod causes each piston to reach TDC at different point in crankshaft rotation

When removing a shielded spark plug, which of the following is most likely to be damaged? (8546)

Core electrode

The field of a series-wound motor contains a few wraps of heavy wire and?

Draws high initial current

A turbine engine has two modes of operation, high output and continuous. continuous operation is selected for?

Heavy rain, snow and ice

Turbine engine igniters wear less than spark plugs because?

They only operate a short period of time

Annular gap igniter plugs are considered?

Long reach because they extend into the burner can

DC Start-Generators contains

A series field and a parallel field

Air turbine starters are generally designed so that reduction gear distress or damage can be detected by? (8629)

Inspection of a magnetic chip detector

Low pressure pneumatic starters typically operate on?

35 psi

Turbine engine ignition systems require high energy because they must? (8606)

Ignite fuel at high altitude with low temps

How are radial engine spark plug wires connected to the distributer? (8551)

By use of cable piercing screws

Sharp bends should be avoided in ignition leads primarily because? (8565)

Weak points may develop in the insulation and high-tension current can leak

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 scheduled starter drop out because? (8633)

The starter will overspeed at a given N2

Airflow to the pneumatic starter from a ground unit is normally prevented from causing starter over speed during engine start by? (8630)

Activation of a flyweight cutout switch

Given a Bendix S4LN-4200 magneto, what would be a typical breaker point material used during overhaul?

Tungsten

Which of the following starting aids is energized by the battery and provides pulsed voltage to the magneto’s primary coil?

Induction Vibrator

A magneto is considered in the full register position when?

The rotating magnet is aligned with the pole shoes

The commutator segments on a starter armature are made of?

Copper

What is the relationship between distributor and crankshaft speed of an aircraft recip. engine? (8605)

The distributor turns at ½ crankshaft speed

The purpose of an undercurrent relay in a turbine engine starter system is to? (8619)

Disconnect power from the starter and ignition when sufficient engine speed is reached

Series wound starter motors fields have which of the following characteristics?

Few turns of HEAVY wire with LOW resistance, and High starting current

One purpose of a growler test is to determine the presence of?

A shorted armature

Inspection of pneumatic starters by maintenance technicians usually includes checking the? (8628)

Oil level, and magnetic drain plug condition

A series wound DC motor will normally require?

More current at low RPM than high RPM

To what depth is the mica insulation between the commutator bars of a DC generator undercut?

Equal to the width of the Mica

The capacitor-type high-energy ignition system is used on turbine engines because of the high voltage and extremely high heat intensity of the spark is produces

True