Chap 8

Question 0

What component of a starter generator require periodic inspection?

Answer 0

Both commutator and brushes should be inspected for wear beyond operational limits

Question 1

How can the remaining service life of starter generator brushes be determined

Answer 1

By visually inspecting the amount of wear groove remaining on the brushes

Question 2

Between field and Armature winding in Starter generator, which ordinarily receive current for operation in the start mold?

Answer 2

Generally, both field and armature received current for operation into start mode

Question 3

What are possible sources of low pressure compressed air used for starting jet transport aircraft equipped with air turbine starter?

Answer 3

A GPU, an APU , or air from another already running engene

Question 4

When should ignition ideally occurs?

Answer 4

A specific number of degrees, before piston reaches TDC on the compression stroke

Question 5

Why are dual magnetos used on engine ignition system?

Answer 5

To improve combustion efficiency and provide redundancy for safety

Question 6

Why are magneto timing so important?

Answer 6

If not timed properly engine may run rough or may not run at all. First internal timing and then magneto to engine timing is adjusted

Question 7

What function does a magneto perform?

Answer 7

It produces a high voltage that forces a spark to arc across a spark plug gap

Question 8

Name the components of a high tension magneto system

Answer 8

Magnetic,primary and secondary

Question 9

What is an E-gap angle?

Answer 9

It’s a point a few degrees beyond the neutral position of a rotating magnetic where maximum magnetic stress exists

Question 10

What reduces arcing in the points and also aids the collapsing of the magnetic field in a magneto?

Answer 10

A capacitor

Question 11

How does a magneto produce the high voltage required to fire a spark plug?

Answer 11

In the rotating cycle, at the E-gap position, the primary point open, inducing a high voltage in the secondary coil

Question 12

What is a P-lead and how does it function?

Answer 12

The p-lead connects the ignition switch to the primary circuit of the magneto. When ignition switch is off, the p-leads on both mags are grounded.

Question 13

What’s a magneto timing light used for and what does it indicates?

Answer 13

Is used for both internal magneto timing and magneto-to-engine timing. It indicates the exact instant the magneto points open.

Question 14

Why are turbine engine igniters not susceptible to Carbon fouling?

Answer 14

Because the high energy spark cleans off any deposited on the firing end

Question 15

What’s the function of a duty cycle in relation to a turbine engine ignition system?

Answer 15

It allows the operation of the ignition system for a given amount of time and is then followed by a minimum specified cooling down period

Question 16

What are the three main components of a turbine engine ignition system?

Answer 16

Ignition exciters, high tension leads, igniters

Question 17

What is done to ensure that each generator shares the load in a multiple generator system?

Answer 17

The generators are paralleled

Question 18

Where would you find generator rating and performance data?

Answer 18

On the data plate attached to the generator

Question 19

How is voltage of a DC generator controlled?

Answer 19

By varying the field current strength

Question 20

What is the most common type of alternator use the most aircraft AC systems?

Answer 20

The three-phase alternator

Question 21

How does a voltage regulator controls the voltage of an alternator?

Answer 21

By regulating the voltage outputs of the DC exciter

Question 22

What does the speed of rotation and number of poles of an alternator determine?

Answer 22

The frequency of the alternator output

Question 23

What are some of the methods used to maintain 400 Hz alternator output frequency on large turbojet or torbofan engines?

Answer 23

Constant speed drives, integrated drive generator and variable speed constant frequency power systems

Question 24

Name the major parts of a DC motor

Answer 24

The Armature, field, brushes and frame assembly

Question 25

Name the components of a direct cranking electric starter system

Answer 25

An electric motor, reduction gears, and an automatic engaging and disengaging mechanism

Question 26

Name three types of DC motors

Answer 26

Series, shunt and compound

Question 27

What type of DC motor is commonly used for the reciprocating engine started and why?

Answer 27

He series wound motor is commonly used because it has a high starting torque under heavy load conditions

Question 28

What are the operating modes of a turbine engine starter generator?

Answer 28

It operates first as a starter, then as a generator once the engines running

Question 29

What is a possible indication when a starter drags?

Answer 29

Hey dirty or worn starter commutator

Question 30

Where would wire with high-temperature insulation material be used?

Answer 30

When they run closed to high-temperature areas such as exhaust stacks or heating ducts

Question 31

What is the size standard for electrical wire using US manufactured aircraft?

Answer 31

The American wire gauge(AWG)

Question 32

How are wires sizes represented?

Answer 32

By a numbered gauge size. The smaller wire are represented by larger numbers. The smaller size wire normally used in aircraft is 22 gauge

Question 33

What is the maximum slack allowed between the supports of a single wire or bundle installation?

Answer 33

Not over 1/2 inch

Question 34

Why are wire bonded on power plant installations?

Answer 34

To provide a current return path for electrical accessories , and to prevent static discharge