Engines Flashcards
What type of engines does the 737NG have? Rated thrust?
2x CFM56-7 engines.
27,300 pounds depending.
What is the N1 rotor consisted of?
Fan, low pressure compressor and low pressure turbine.
What is the N2 rotor consisted of?
High pressure compressor and high pressure turbine. All engine gearboxes are powered off the N2 rotor including accessory gearbox and a bleed air starter drives the N2 rotor for engine start.
How many ignitor plugs per engine?
2 congrolled through the IGN switch.
T/F: The dual channel EECs ensure reliablity through automatic transfer in the event of a _______.
single channel failure.
What are the two modes for the EECs?
Normal or Alternate (alternate has hard and soft mode).
T/F: Max thrust is always available at the forward stop
true
____ and ____ overspeed protection is provided by the EECs in both normal and alternate mode.
N1, N2
T/F: The EECs provide EGT exceedance protection in normal.
false
How do you get to alternate mode in the EEC?
EEC automatically goes to soft alternate when signals for normal are lost. This will be indicated by both the ON and ALTN lights in EEC switch.
Going from Normal to Soft Alternate shouldn’t have any immediate effect on engine thrust since this mode does what?
uses last valid flight conditions to control parameters.
How do you get to Hard Alternate for the EECs?
retarding thrust levers to idle or manually selecting ALTN via EEC switch.
For a given thrust lever position, Hard alternate will _______.
Always provide thrust equal to or greater than that provided in Normal.
What is the difference between ground min idle and flight min idle?
ground: selected during taxi out and after touchdown
flight: selected in flight unless approach idle is active.
How is approach idle selected?
flaps are in landing configuration or anytime engine anti-ice is selected ON for either engine. Approach idle allows for better engine acceleration in event of go around.
An AC power source is generally preferred but the engine can be started using ______only
battery
What are the power sources for IGN L and IGN R?
IGN L: associated AC XFR BUS
IGN R: AC STBY BUS.
Which ignition must be used for a battery start?
IGN R
How do the EECs provide auto-relight capability?
In event of flameout both ignites are activated automatically when N2 RPM is below idle or a rapid uncommanded decrease in N2 RPM occurs.
What does a magenta X-BLD mean?
ambient flight conditions require a crossbled start.
______and _______ engine starts are available in flight however the abnormal start protections _________.
Windmill; crossbled; are not available.
The _____ meters fuel through the ______ to control required engine thrust.
EEC; HMU (hydro-mechanical Unit)
How many engine fuel pumps are there?
2; 1st stage is after spar fuel shutoff valve; 2nd is after fuel filter and goes to HMU.
SPAR VALVE CLOSED and ENG VALVE CLOSED (blue ) indicate what?
position of the valves.
Where is the fuel flow readings taken from?
just after the Engine Shutoff valve
Oil from the engine driven oil pump is used for what?
lubricate the engine bearings and accessory gearbox.
When does LOW OIL PRESSURE display?
oil pressure is at or below red line.
Reverser operation will be at a _________ and some thrust asymmetry can be expected when using standby hydraulic pressure.
slower rate.
The reverse thrust levers are mechanically restricted from operating until at _______.
IDLE. Also, reverse thrust can only be deployed when either RA is reading below 10’ or ground mode is sensed through Air and Ground safety sensor.
Movement of either reverser sleeve from the stowed position will illuminate an _________ indication.
amber REV.
The green REV displays when?
once the reverser has reached the deployed position and the reverse thrust lever can no go to the second detent.
If you get a MC light and the REVERSER amber light is on what has happened?
The reverser light has stayed on for more than 12 seconds. A mulfunction exists.
Once a reverser is stowed, motion is inhibited by an ________ lock and a ________ operated locking actuator until extension is selected.
electro-mechanical lock; hydraulically
Which engine indications are considered primary?
N1 & EGT
The N1 redline always indicates the N1% RPM ?
operating limit
After shutdown, a red box around a digital readout indicates what?
Upgrade To Pro
Inflight exceedance has occured.
With AUTO selected, ref N1 readouts are replaced with ______ should the FMC source info become invalid.
dashes
Where are thrust mode display annunciations shown?
Next to TAT on the Primary Eng DU
When does Autothrottle limit indication show up?
FMC is not providing the AT system with N1 limit values. AT are essentially using degraded N1 thrust limit by EEC.
Where is stabilized idle for start?
approx. 59% N2.
How is max continuous EGT line displayed?
amber line at EGT
A white flashing box of the EGT means what?
impending hot start or compressor stall.
What does an amber ENG FAIL light mean on the EGT gauge?
Start lever is in IDLE and engine is operating below 50% N2. It remains until the engine recovers, the FIRE switch is pulled or the start lever is moved to CUTOFF.
Fuel flow readouts can be adjusted to show?
Present FF or F used.
