15.13 start & ignition Flashcards
what is sometimes used on gas turbines engines and provide a quick a independent method of starting
cartridge starter
what initiates the burning of the cartridge charge
an electrically fired detonator
what kind of starter is used on most commercial jet engines
air starter
what does an air starter motor starter motor transmits power through
a reduction gear and clutch to the starter output shaft which is connected to the engine
There are generally two types of electric starting systems used on gas turbine engine aircraft
Direct cranking electrical systems
Starter-generator systems
what are most gas turbine engine aircraft equipped with
a starter-generator system
when could continuous ignition mode be used
during certain flight conditions
what does a typical ignition system include
two exciter units, two transformers, two intermediate ignition leads and two high tension leads
Why must the starter continue to assist the engine considerably above the self accelerating speed
To avoid a delay in the starting cycle
What is the air supply to the starter controlled by
An electrically operated control and pressure reducing valve
When would the sprag clutch assembly engages automatically
As soon as the rotor starts to turn
What happens if the air starter valve fails to open
There is usually some form of manual valve override to Allow engine start
When would continuous ignition be used
If there is a possibility of an engine flame out, to relight the fuel and keep the engine from stopping
What is the generator directly turned by
The engine through the accessory gearbox
What does a typical ignition system include
Two exciter units, two transformers, two intermediate ignition leads and two high tension leads
What happens before electrical energy reaches the exciter unit
It passes through a filter that prevents noise voltage from being induced into the aircraft electrical system
What is an exciter
A dual unit that produces sparks at each of the two igniter plugs
What is the reason that exciters are cooled
To prevent overheating during long use of continuous ignition
