Powerplant Ignition And Starting Systems

Front 1

What is the main advantage of a magneto ignition system over a battery ignition system in an aircraft reciprocating engine?

Back 1

The magneto has it's own source of electrical energy

Front 2

What is the function of the capacitor in a magneto?

Back 2

Prevents arcing and speeds up the breaker points opening

Front 3

What is a compensated magneto cam, and in what kind of engine is it used?

Back 3

Special cam magneto used on radial engines which has one lobe for each cylinder, arranged in such a way that the breaker points open on the Pistons in the different cylinders at the same linear distance from the top center

Front 4

What is the significance of the numbers on the distributor of an aircraft magneto?

Back 4

The sparking order of the magneto

Front 5

What happens in a magneto ignition system when the ignition switch is placed in the off position?

Back 5

Primary circuit is grounded

Front 6

What is the reason for having a low tension ignition system on some aircraft?

Back 6

Because of the problem with flash over from high tension magneto distributors if the aircraft is flying at certain high altitude

Front 7

What is the basic difference between a low tension magneto and a high tension magneto?

Back 7

Low tension magneto has only one coil in the magneto, uses carbon brushes, and uses a high tension transformer

High tension magnetos produce high voltage which is sent to the correct spark plug by a high voltage distributor

Front 8

What is meant by an all weather sparkplug?

Back 8

Spark plug with a resilient grommet on its ignition leads that form a water tight seal

Front 9

What is meant by the sparkplug reach?

Back 9

The amount of the spark plug that is screwed into the cylinder

Front 10

What's the difference between hot sparkplug and cold spark plug?

Back 10

Hot sparkplug has a longer heat travel between the nose core and the insulation, while the cold spark plug has a shorter travel distance between the sparkplug nose core and the insulation so it operates cooler than a hot sparkplug

Front 11

How to check when a magneto is initially timed?

Back 11

The E-gap position to make sure that the breaker points will open at the right time when distributor sends the high voltage to the cylinder number one

Front 12

What is the purpose of a vernier coupling used on some aircraft magneto drives?

Back 12

Allows for magneto-to-engine timing variations in increments of less than 1°

Front 13

What is the advantage of a thin wire spark plug over a massive electrode spark plug?

Back 13

It doesn't collect lead contaminants from the burned gases as the massive spark plug would due it being more open than the massive electrode spark plug

Front 14

Why is it important that the spark plugs be kept in a numbered holes in a tray when they are removed from the engine?

Back 14

Because they identify the condition of the cylinder and the number helps to tell from which cylinder the spark plug was coming from

Front 15

What is the purpose of a staggered timing between the two magnetos on an aircraft engine?

Back 15

It used in engines which the exhaust gas scavenging from the cylinder is uneven to allow for the flame front caused by the two spark plugs to meet in the center of the piston,

Front 16

In which position should the ignition switch be placed when using a timing light on the magneto?

Back 16

Both position

Front 17

Why is it important that a torque wrench is always used when installing spark plugs in an aircraft engine?

Back 17

Because if there's an improper torque there could be a poor seal and an over-torque could cause a crack in the insulation on the spark plugs

Front 18

Why are pressurized magnetos used on most reciprocating engine powered aircraft that fly at high altitudes?

Back 18

Pressurized air is a better insulator than less dense air and by pressurizing the distributors the high voltage is kept from jumping across to the wrong electrode and causing vibrations or loss of engine power

Front 19

What type of ignition system is used on most turbine engines?

Back 19

High intensity intermittent-duty capacitor discharge ignition systems

Front 20

What is the function of an impulse coupling?

Back 20

To produce a hot and late spark

Front 21

What is meant by the E Gap in a magneto timing?

Back 21

The position on the rotating magnet of the magneto when there is the greatest flow of current in the magneto coil, usually when the breaker points begin to open

Front 22

What kind of gauge should be used to measure the electrode Gap in an aircraft spark plug?

Back 22

A round wire gauge

Front 23

How many igniters are used in most turbine engines?

Back 23

2

Front 24

What are the two types of igniter systems used in turbine engines?

Back 24

High voltage and low voltage

Front 25

In which type of ignition system is a glow plug igniter used?

Back 25

A low voltage system

Front 26

How is the strength of a magnet in a magneto checked?

Back 26

Rotated on a test stand at a specified speed and the breaker points are held open and the primary current is measured, the strength of the magneto determines the amount of the primary current

Front 27

In what position is the magnet in a magneto when the greatest change in flux density in the coil core takes place?

Back 27

Few degrees before the neutral position

Front 28

In what position is the magnet in the magneto when the breaker points begin to open?

Back 28

A few degrees past then neutral position

Front 29

What malfunction in the ignition system will cause an aircraft reciprocating engine to continue to run after the ignition switch is placed in the off position?

Back 29

The ignition switch is not grounding the magneto primary circuit

Front 30

What turns on the autoignition system in a turbiprop engine?

Back 30

A torque pressure switch energizes the system when the engine stops producing torque