Engine Flashcards
Which two engine indications are displayed full time on the Eicas?
N1 and EGT
State the start sequence with Autostart on
Pull Engine START switch
- arms start valve (start switch illuminates)
- opens engine bleed air valve
Fuel control switch up to RUN
- opens spar fuel valve
- opens engine fuel valve
•(Auto) Initiates start sequence
- eec sequences start valve
- at predetermined N2 EEC opens fuel metering valve
- EEC energizes selected igniter
•At 50% N2
- Start switch releases (starter cutout commanded)
- start valve closes (light out)
- engine bleed valve opens
- ignition cut out
What does (and does not) the EEC monitor during engine start
Does:
- EGT and N2 until stable and idle
- Abort for: Hot start, Hung Start, No EGT
Does not:
- oil pressure
- N1 rotation
If first start unsuccessful autostart
Purge fuel
Motor 30 sec
Applies fuel and both igniters
If necessary will make 3rd attempt
If fails:
Fuel and ignition cut off
Eng motored 30sec
Start and bleed valves close
EICAS 1,2,3,4 autostart
Start sequence with AUTOSTART off
Engine start switch - pull
- opens start valve
- opens engine bleed air valve
Fuel control switch - RUN (N2 to indicator)
- spar fuel valve opens
- engine fuel valve opens
- Selected igniter energizes
50% N2
- automatic starter cut out
- start switch released to IN
- start valve closes
- engine bleed valve closes
- ignition de energizes
- EGT start limit blanks N2 predetermined limit
What two valves close at 50% N2
Start valve
Engine Bleed valve
Function of the Auto ignition selector in the SINGLE position
EEC alternates igniter 1 and 2 for each ground start
Both igniters for engine flame out recovery
Function of the STBY IGNITION selector in NORM
AC power supplies to igniters
AC not powered, Stby system supply’s continuously to all igniters
(In 1 or 2 Stby power supplied continuously to selected igniter
What happens when you turn the CON IGNITION switch ON?
Provides continuous ignition to selected igniters in all engines
Memo message CON IGNITION ON
Engine RPM to approach idle
Ignition selected for each engine individually
During start: switch pulled and N2 less than 50%
Engine nacelle anti-ice (NAI) on
Engine flame out detected
Trailing edge flaps not up
Ignition selected for all engines simultaneously
Trailing edge flaps out of UP
Continuous ignition switch selected on
EGT start limit exceeded color change
Red
X-BLD when next to N2 and engine shut down
X-BLD air required for start
(Airspeed is two low for windmilling)
Describe the sequence of engines to be started
4,1,2,3
Or
4&1, 2&3
Auto start aborts for
And
Does not monitor for
Hot start, hung start, no light off (egt rise)
Oil pressure, N1 rotation
How does the EEC abort a start?
On Ground:
- No EGT rise:
1. Cuts fuel and ignition
2. Motors for 30 sec
3. Three attempts before aborting starting sequence (start and bleed valves close)
- Impending hot or hung start:
1. Cuts off fuel
2. Adjusts fuel schedule
3. Reapplies fuel for another start
4. Three attempts before aborting start
5. Motors for 30 sec before bleed and start valves close
At what limit does the EEC abort and inflight start through the Autostart system
EGT reaching takeoff limit: EEC cuts off and reapply fuel
How is engine cooled
Oil
(Which is cooled by fuel through a heat exchanger
How is the engine thrust reverser actuated!
Pneumatically
What protects the thrust reversers from deploying inadvertently in flight?
Locked in flight
If unlocks and deploys reverser system automatically applies bleed air to stow and lock
What is broadband vibration in the airborne vibration monitoring system
How is it displayed?
Source of the vibration cannot be determined
Indicated as BB
