15.13 Flashcards
(24 cards)
What is the role of a starter system
Send compressed air to the engine to spin the hp compressor
What is a dry motor run
Run the engine on the starter motor without putting fuel in the engine
Why is a dry motor needed
Cooling and maintenance
What is the start sequence
Ignition on
Starter valve opens Up
Fuel on
Engine lights up
Engine attains self accelerating speed (self sustaining)
Ignition off
Starter cuts out
Engine at idle
Why is the starter left on until engine is at idle
To prevent a hung start
Which starter has a small impulse turbine driven by high velocity gasses
Cartridge starter
What is the advantage of an air starter
Comparatively light, simple and economic to operate
What psi does the air-start provide
30 to 50 psi
How does and air starter disconnect for the engine
A sprag clutch
When does a sprag clutch disconnect and how
When engine attains idle the centripetal force depresses springs and clutch disconnects
True or false, air started has its own oil system and chip detector
True
How so a direct crank electric starter couple to the engine
Via a reduction gear system
When does a direct crank electric start disconnect
When engine is self sustaining
What starter is the same as a dc starter but does not have a clutch
Starter generator
Stays connected to the engine and acts as a generator
What is the advantage of a starter generator
Less maintenance needed cos no clutch
When is continues ignition mode used
When high possibility of flame out
Operating on take off or landing
Hail storm of volcanic eruptions
What different about stater ignition and continuous ignition
Continues operates at a lower voltage and energy level
How are the igniter plugs cooled
Via fan air
What can the ignition system be powered
115 AC
Battery
Permanent magnetic generator
Accessory gear box
What in the ignition system is there two of
Exciter units
Transforms
HT Leads (high tension leads)
Why is an exciter box hermetically sealed
Eliminates flash over at high altitudes
Capacitor discharge exciter unit
Energy stored in capacitors
Connected with HT leads
Continues series of sparks till engine start
What are the two types of igniter plugs
Long reach, projects slightly into the combustion chamber
Constrained gap plug, does not project into combustion chamber
Where should u disconnect a ht lead first
Disconnect at exciter coupling first before disconnecting from igniter plugs
