Oral: Engine Questions Flashcards
Know
What types of engines are on the aircraft?
- Two General Electric CF-34-8E5
* Hi-bypass, 2-spool, axial-flow, turbo-fan
How much thrust do the CF-34-8E5 engines produce?
13,000-14,200 lbs. (ISA)
Describe N1 spool
- Single-stage fan
* 4-stage LP turbine
Describe N2 spool
- 10-stage compressor (gas generator)
* 2-stage HP turbine
How many igniters per engine?
2 per engine
How many igniters activate for engine start?
- Ground = 1 igniter ( switch in AUTO )
* Flight = 2 igniters ( switch in AUTO )
What happens when the ignition switch is selected to OVRD?
•Activates both igniters on the ground or in flight
Can the igniters be turned off during flight?
- The switch may be moved to the OFF position but the FADEC disregards the command
- The OFF position is used for dry motoringon the ground only
What controls the engine?
- A two-channel FADEC
* One channel is active and the other channel remains in standby as a backup
Is only one FADEC channel used every flight?
No. They automatically alternate with each engine start
What does the cyan line on the N1 gauge represent during approach?
When does it appear?
- The minimum N1 for bleed requirements in icing conditions
* Configured for landing < 1200’ RA (when anti-ice is ‘ON’)
What sources are available for engine starting?
- APU
- Ground source (huffer cart or air bottle)
- Opposite engine(crossbleed start)
- Windmill start
Does the FADEC provide engine start protection?
Only on the ground for a hot start, hung start or no light-off
What will the FADEC automatically do in case of a HOT start on the ground?
- FADEC will not allow FF if ITT >120°C
* FADEC will automatically dry motor engine and introduce fuel when ITT <120°C
Describe the engine start sequence:
Start…
Stabilizing…
•Start switch momentarily to START:
- 7% N2 Ignition
- 20% N2 Fuel flow
- 20% N2+ 5 sec Light-off
- 50% N2 Ignition off
- 50% N2Starter cutout
Engine stabilizes:
- N1 [27%]
- ITT [460°C]
- N2 [62%]
- FF [550 lbs/hr]
- Oil Pressure [>25 psi]