Power plant Flashcards
The variable geometry (VA) system varies the position of the inlet guide vanes and the stator vanes on stages
1 to 4
The CF34-8C5, with APR has a thrust rating of
13,560-14,750 lbs
What engine model is on the CRJ 900 series aircraft
CF34-8C5
During normal operations the DCU monitors
N1, N2, ITT, oil pressure, oil temp, engine vibration and fuel flow
6th & 10th stage bleed air is used for
Air Conditioning
The engine may be started by the APU, ground source, or engine crossbleed T/F
True
Crossbleed air starts require?
Operating engine to achieve 42 psi
IGN B (igniter) is powered by
Battery bus
Ignition cut-out occurs at
50% N2
Refilling of the oil system is provided by the replenishment tank located in the:
Aft equipment bay
Engine oil is cooled by
Fuel/oil heat exchanger
80% of engine thrust is generated by
Bypass air
How are CRJ engines protected against compressor stalls and surge protection
Variable geometry vanes
Under what condition can FADEC be set to FLEX thrust (verified 7/22/2013)
Thrust levers idle or shut off detents
WOW for at least one minute
Assumed temperature is greater than OAT
airspeed is less than 65 KIAS
(Must be entered into the FMS)
When will OEO thrust be activated
N1 mismatched 15% RPM
The left engine is the master engine for
N1 & N2 sync
The primary thrust setting reference is
N1
With wing Anti-Ice on, the N2 RPM indicators will
Turn white from 0-77%
The left engine START switch light, when pressed in
Opens the left bleed air start valve and the isolation valve
After engine shutdown, engine oil level should be checked within:
3 minutes to hours.
What is the make and model of the engines in the CRJ 900?
General Electric CF34-8C5
The engine’s accessory gearbox is driven by what?
The N2 compressor
When is OIL LEVEL LO status message displayed?
When oil quantity is less than 20%.
When must continuous ignition be used?
Takeoffs and landings on contaminated runways
Flight through moderate or heavier intensity rain
Flight through moderate or heavier intensity turbulence
Flight in the vicinity of thunderstorms
What is the bleed air source for the CRJ 900 air conditioning system?
6th or 10th stage Axial compressor.
How is the air conditioning pack pressure controlled on the CRJ 900 when the engines are supplying bleed air?
Pack valves
Bleed air is taken from what stages of the engine compressor?
6th or 10th stages.
Engine N1 speed governing is a function of:
FADEC
CF34-8C5 takeoff and APR thrust values are ——- & ——- foot pounds.
13,560 & 14,750
N1 and N2 synchronization is available during:
Cruise flight
N1 consists of what?
1 fan rotor in the very front that is connected to a four stage low pressure turbine in the back of the engine. This four stage turbine is accelerated by the exhaust high pressure air from the N2 section. The four stage low px turbine in the very back drives the fan rotor in the front( cause it’s connected)
N2 consists of what ?
A ten stage axial (center) flow compressor, a combustor, accessory gearbox and a two stage high px turbine aft of the 10 stage compressor. The two stage compressor is driven by the exhaust air from the 10 stage which turns the 10 stage compressor faster.
What is the accessory gearbox attached to ?
N2 compressor
What is on the accessory gearbox ?
Fuel pump and (FMU) fuel metering unit IDG Starter (Air turbine starter) Hydraulic pump OIL lubrication pumps \+ FADEC alternator \+ Integral oil reservoir
What does the FADEC alternator do ?
Completely separate power source for FADEC. ABOVE 50% N2, it powers both FADEC channels.
What is the Air Turbine Starter ?
Starts the engine by turning pneumatic energy into mechanical motion.
What is the minimum PSI on the operating engine for a cross bleed start ?
42 PSI
