Engines Flashcards
Describe the engines
CFM56-3 dual rotor axial flow turbofan
What is the PMC
Power Management Control
: electronic system that that has a limited authority over the main engine controls (MEC)
Inputs into PMC
Power lever angle
N1 speed
Inlet temp and press are used to adjust N1 speed and fuel flow.
Engine Low Idle and High Idle
High Idle is for all phases of flight. Average high idle setting is 32%
Low idle is used to reduce braking activity, approximately 22% four seconds after touchdown.
(4 secs to enhance reverse thrust)
Fuel delivery system
“fuel tanks valve pump heat bypass high shutoff”
- fuel tanks
- fuel shutoff valve
- 1st stage fuel pump
- fuel oil heat exchanger
- fuel filter (or filter bypass)
- high pressure fuel pump
- (portion goes to) MEC
- engine fuel shutoff valve
Engine oil delivery system
- start at oil pump
- filters and oil pressure sensor
- engine bearings and gearbox
- scavenge pumps recover engine oil
- scavenge filter and oil temp sensor
- fuel oil heat exchanger
- back to oil tank
Engine start system
Uses bleed air and electrical power
GRD position of engine start switch
DC power from bat bus closes engine bleed valve and opens start valve (25% N1 or max motoring)
Moving engine start levers to idle does what?
Opens fuel valves and causes MEC to supply fuel to combuster. (Starter cutout appx 46% N2)
Ignition system select switch
Each engine has two (2) igniters
L side is powered by AC transfer bus
R side is powered by AC standby bus
Thrust Reversers
Hydraulically operated
can be deployed under 10 ft RA or when air/ground safety sensor is in ground mode and thrust levers in idle position.
REVERSER light
On aft overhead panel
illuminates whenever TR is commanded to stow and extinguishes 10 seconds later.
If REVERSER light stays on for more than 12 seconds a malfunction has occured and the MASTER CAUTION and ENG lights illuminate
