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Flashcards in Electrical / ignition Deck (23):

What components of the starter generator require periodic inspecting

commutator and brushes should be inspected for wear beyond operational limits


Between field and armature windings in a starter generators which ordinarily receive current for operation in the start mode

Generally both field and armature do


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

Ground power unit, an on board APU, compressed bleed air form an already running engine


When should ignition ideally occur

Specific number of degrees before the piston reaches top dead center on the compression stroke


Why are dual magnetos used in engine ignition system

To improve combustion efficiency and provide safety in case one magneto fails


What function does a magneto perform

Provides high voltage spark to arc across a spark plug gap


Name the components of a high tension magneto system

Permanent multipole rotating magnet, soft iron core and pole shoes


Name three main circuits of a high tension magneto system

Magnetic, primary, and secondary


What is E-gap angel

It's a point a few degrees past the neutral position of a rotating magnet.


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



What is a magneto time in flight used for and what does it indicate

Used for internal magneto timing and magneto to engine timing. It indicates when the points are open


Why are turbine engine igniters generally not susceptible to carbon fouling

Because high energy sparks cleans off any deposits in the firing end


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

Frequency of the alternator output


What is the most common type of alternator used in most aircraft AC systems

Three phase alternator


How is the voltage of a DC generator controlled

By varying the field current strength


Where would you find generator rating and performance data

On the data plate attached to the generator


What are the three mani components of a turbine engine ignition system

Ignition exciters, high tension leads, and igniters


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

Generators are parallel


How can the remaining service life of a starter generated brushes be determined

By visually inspecting the amount of wear remaining on the brushes


What is a magneto

A self contained AC generator driven by the engine for ignition to start a reciprocating engine


What is a dual magneto

It is two magnetos that are in one housing. They share the cam, and rotating magnet but have separate sets of points, coils, and distributor blocks


What is internal timing of a magneto

It's when the breaker points are adjusted to open when the poles of the rotating magnet are at the E-gap position


Why is magneto timing so important

For an engine to run properly