Engines Flashcards
What series engines are used and up to what thrust?
IAE V2500 series, up to 26500lbs.
What does the N1 rotor section comprise of?
A fan and a 4 stage low pressure compressor, which is driven by a 5 stage turbine.
What does the N2 rotor consist of?
10 stage high pressure compressor driven by a 2 stage turbine.
How many fuel nozzles inject fuel into combustion chamber? And how many FADEC controlled igniter plugs are there?
20 fuel nozzles.
2 igniter plugs.
How is the accessory gearbox driven?
Mechanically connected to the N2 rotor by a drive shaft.
Does FADEC provide protection of N1, N2 and EGT limitations?
-N1 and N2 overspeed protection, both in forward and reverse.
-EGT, only during automatic and manual starts on the ground. No protection in flight.
How many channels on each FADEC and can 1 operate if one fails?
2 channels. Yes- other channel automatically takes over if one fails.
How does FADEC self test take place?
When aircraft is first powered, aircraft electrical system powers FADEC for 5 minutes while the system performs a self test. On completion power is automatically disconnected.
Why should ENG MODE selector be only rotated to ENG START just before start?
To avoid FADEC overheating, as it produces substantial heat when operating.
How is FADEC powered while engine is running?
When engine rotation speed is sufficient, power source automatically switches to the dedicated alternator.
What happens to FADEC power source when engine is shutdown?
Automatically switched to aircraft electrical system for 5 minutes, then disconnects.
What happens if EPR mode fails? (3 items) Should the other engine be left on EPR mode?
-amber XXs replace EPR indications.
-affected engine automatically reverts to N1 mode.
-autothrust and alpha floor are lost.
No- other engine should be manually selected to N1 mode.
What is the difference between rated and degraded N1 mode?
RATED N1 MODE- loss of sensed EPR- (P2 (inlet) and/or P5 (exit) not available)
FADEC will determine N1 power setting as a function of TLA, altitude and engine inlet total temperature. Can be manually selected through ENG N1 MODE pb-sw.
DEGRADED N1 MODE- loss of computed EPR due to loss of T2 (inlet temperature) or ambient pressure (ambient pressure engine sensor) engine parameters.
The N1 is defined as a function of TLA only and is limited by the FADEC to either:
‐ The smallest of maximum N1 or N1 redline, if T2 is available, or
‐ The N1 redline if T2 is not available.
The degraded N1 mode is an unrated N1 mode.
The N1 rating limit and maximum N1 indications on ECAM E/WD are lost.
In electrical emergency configuration, the EPR mode is lost on both engines, and each FADEC reverts to the degraded N1 mode.
Note: An overboost can occur during reversion in the degraded N1 mode, with thrust lever at full forward position.
What pumps are downstream after the fuel tank pumps and LP valve?
LP Pump (first stage) and HP Pump (second stage).
Does IDG run hotter at low or high thrust settings?
Hotter at low thrust. At high the demand to keep the IDG operating at the proper speed is less.
Where does IDG cooling fuel mostly flow at high thrust settings?
Returned to main fuel flow to be burned in combustion chamber.
Where does IDG cooling fuel flow (in addition to combustion chamber) at low thrust settings? (3 levels as fuel temp rises)
1st- FADEC opens a recirculating valve and routes a fixed amount of warm fuel to outer tanks.
2nd- FADEC will increase minimum N2 to reduce strain on IDG.
3rd-FADEC increases flow of hot fuel back to wing, in proportion with temp rise.
*when returning hot fuel to tanks, FADEC also mixes in some cold fuel to ensure temp stays below a max threshold.
When does FADEC activate both igniters simultaneously? (5 items)
-manual start.
-engine anti-ice selected ON.
-ignition delay is detected during automatic ground start.
-EIU fails.
-engine flameout is sensed.
What is starter motor connected to within engine?
Directly connected to engines N2 rotor shaft.
At what N2 does start valve close and ignition automatically turn off, during an automatic start?
43%
Is there a backup for a failed engine start valve?
Valve can be manually externally operated by maintenance personnel.
When is modulated idle active on ground and in flight?
Ground- as long as reverse NOT selected.
Flight- while slats and flaps retracted.
What idle will be active if both LGCIUs fail?
FADEC will default to approach idle as a safety precaution, should aircraft lose the ability to determine if it is on the ground or in flight.
When is approach idle normally active and why?
When flaps or slats are extended as it significantly reduces time taken to accelerate engine from idle to go around thrust.
When is reverse idle active and how does it compare to modulated idle?
Active when on the ground with thrust levers in REV IDLE.
Slightly higher than modulated idle RPM.
Which hydraulic system powers which engine blocker doors for reverse thrust?
Engine 1- green.
Engine 2- yellow.
Can full reverse thrust be immediately selected?
Yes, however FADEC will not permit engine thrust to increase beyond reverse idle until all blocker doors are fully open/locked (takes about two seconds).
How can the LP and HP valves be closed?
FIRE pb- LP
ENG MASTER switch- LP and HP
What is the maximum N2 to engage starter?
20% N2.
What indicates the start sequence is complete?
Green AVAIL appears on EPR gage when engine reaches stable IDLE.
Also gray background on N2 disappears.
