powerplant Flashcards
engine type
CFM56-7 engines
dual rotor
axial flow
turbofan.
what does N2 rotor drive?
engine gearboxes
Accessories:
fuel pump oil pump integrated drive gen starter hydraulic pump
N1 / N2 compressors
high or low?
N1 low pressure
N2 high pressure
which sort & which compressor is the starter motor connected to?
air start (bleed) connected to N2 rotor
EEC?
a dual channel electronic engine control regulates each engine.
It monitors autothrottle & flight crew inputs to automatically set thrust.
primary engine indicators?
N1
EGT
displayed on upper DU.
if that fails, auto displayed on lower DU
secondary engine indicators?
N2, fuel flow, oil px, temp, quant Vibration.
EEC auto switch between channels?
what input does it use?
what modes?
2x channels
auto transfer if operating channel fails.
also with every engine start or start attempt.
N1 used by EEC to set thrust.
Normal/alternate
EEC normal mode
what’s used?
sensed flight conditions & bleed air demand is used to calculate N1 thrust ratings.
EEC compares commanded N1 to actual N1 & adjusts fuel flow to achieve commanded N1.
EEC protection?
which modes?
what’s unprotected & must be monitored by crew?
EEC provides N1 & N2 red line overspeed protection
in both normal & alternate modes.
EGT limit. No EEC protection.
EEC & Idle
different types?
EEC auto selecs:
ground min idle
flight min idle
approach idle
Approach idle
when?
what is it?
config failure to trigger?
selected in flight when:
flaps are in landing config
or
engine anti ice is on for either engine
at same airspeed & ALT, N1 & N2 RPM will be higher than flight idle.
I no flap or anti ice signals received due error?
Approach idle schedule will start below FL190 msl
started operation requires what 2 things?
pressurised air
electrical power
