Engine Ignition And Start Flashcards
Each engine equipped with
A bleed air starter motor and bleed air can be provided from the other engine, APU(normally for start) and ground power unit
Starts on ground vs air
One igniter on ground
Both in air
EEC initiates
Auto start
Auto start switch on
Start switch to start
Start valve will open and bleed air will drive starter motor
Fuel control switch to run
This will open spar valve
When engine reaches a certain speed the EEC will open fuel valve and start igniter
If something goes wrong the EEC will automatically shutdown the start sequence
When engine stabilises at idle after start
The EGT start limit line disappears this completes the auto start sequence
Auto start monitors
N1
EGT
N2
FF
Second start attempt by EEC
Uses both igniters
Before second attempt, EEC closes fuel and igniters for 4 seconds before re attempt
Third attempt may modify fuel schedule
Third attempt fails
Auto start abort
Start valve closes
Start switch normal
However fuel switch must be manually placed to cutoff before another attempt made
Manual start
Start switch
Note oil pressure rise
Don’t add fuel until maximum monitoring, N2 increase is less than 1%for approx 5 seconds
In flight start envelope display
Displays automatically on EICAS When Fuel control switch is cutoff N2 RPM below idle The airspeed range ensures that a successful in flight engine start is dispalyed next to the airplanes current flight level
In flight start envelope max alt
Has max alt of FL300
May be possible above but not ensured
In flight auto restarts
Indefinitely or until pilot aborts
Automrelight
Flameout protection Sub idle stall Igniters activates automatically if Rapid decrease in N2 N2 less than idle RPM fuel shutoff for 1 second for sub idle stall Temp discontinued for high EGT
