Systems - Engines Flashcards
(Refer to AOMII 2-14-05 pg 3)
How is 9th stage air supplied and when is it over-rode?
With a 1 way check valve that is always open and over-rode by 14th stage air when that valve is open.
How soon after engine shutdown should the oil be checked to ensure quantities are within the accpetable range
5 mins.
Should you abort the start if FF drops to zero shortly after light off?
No, this could be a normal condition.
What are the steps for a crossbleed start
1) X Bleed Valve to AUTO or OPEN
2) Starting Eng Bleed Closed
3) Operating Eng Bleed Open
4) Operating Eng > 80% N2
What is the purpose of the engine bleeds
Power the AC packs and Anti Ice
(Refer to FPMU schematic 2-10-10 pg 3)
What does the FPMU do?
1) Pumps Fuel
2) Meters the Fuel to the 16 fuel nozzles based on where you place the TL.
What happens if the IGN is selected OFF and Engine is ON
disables the “auto re-light”, but the engine will continue to run.
What will the FADECs do if one reaches a critical fault
It will auto transfer the engine to the other FADEC.
What happens when the IGN is ON
Both igniters spark continuously (there is no limit to how long you can have ignitors on).
(Refer to AOMII 2-14-05 pg 3)
Identify 3 times you are guaranteed air from the 14th stage (highest pressure)
1) Low thrust settings
2) Anti- Ice On
3) Cross Bleed Engine Start
At what minimum oil level should you notify MX control of low oil quantity
8 qts (not a write up)
What is the purpose of Compressor Variable Geometry (CVG)
To make sure that the engine is more efficient and reduce the likelyhood of compressor stalls
When is the ignition required to be ON
When using “off ship” start and cold start.
When does the PMA have sufficient rotation to power the igniters?
at 10%
How many igniters does the comustion section have and how are they operated?
2 igniters (1 at 12 O’Clock and one at 6 O’Clock). Each igniter is operated by its own FADEC (A or B).
What is the PMA and what items does it power?
Permanent Magnetic Alternator and is powered by the N2 compressor. Items powered by PMA:
1) Ignition
2) FADECs above 50% N2
3) Backup power source for Thrust Levers & Thrust Rating Buttons.
Does the Flight Crew have any control over which FADEC will fire the inginters during start?
No, the FADEC will alternate this between legs.
What does Resetting a FADEC do? What does selecting ALTN (Alternate) on the FADEC do?
1) Clears any transient faults
2) Manually switches to the other FADEC in flight.
What is meant by FADECs sending discreet signals
The FADEC is running a system other than the engine
(Refer to FPMU schematic 2-10-10 pg 3)
What happens if the FPMU quits
The Engine Will Quit
If you are operating single engine, and need to perform a Go Around and it is hot outside (greater than 19°C), what will the FADEC do?
Turn off the onside packs and direct bleed air to rearward thrust.
If the fuel pumps become inop, to what altitude will the FPMU “suck feed” fuel
Up to 25,000’
What is the maximum time to engage the starter? What is the typical time? What happens if you exceed the maximum limit?
1) 3 seconds
2) 2 seconds
3) It disables the knob unless you reset the FADEC which clears the knob disable.
Why is the ITT start temp limit reletivley low (800°C) compared to the contunuous operation ITT (901°C)
Becuase the temperature sensor probe is inside a stator and therefore shielded from direct heat.
What technique should you use when deploying Thrust Reverersers before all three mains are on the ground
Limit yourself to idle reverse until nose gear is down
What are the reasons to abort Start (on the ground or in flight)
1) Fuel Flow > 800lbs/ hr prior to light up
2) No light up within 10 seconds after FF
3) ITT rises rapidly towards start limit
4) ITT approaches the start limit
5) N2 remains steady or decreases for more than 30 secs
6) Unusual Noise or Vibration
7) Engine Instruments indicate abnormal conditions
8) Visible burning on the exhaust
9) Oil Pressure <34 psi after the start is complete.
(Refer to FPMU schematic 2-10-10 pg 3)
What does the Fuel- Cooled Oil Cooler do (FCOC)
As the fuel flow from the centrifugal pump to the FCOC, the cold fuel is used to cool down the hot oil and in turn the hot oil will warm the fuel (symbiotic relationship).
At what minimum oil qty should you actually write up?
6 qts.
What are the components of of the N1 low pressure section
1) 24 bladed Fan Drive
2) Inner Shaft
3) Low Pressure Turbine
How are each of the TR locks commanded and operated.
1st two sets are electrically commanded and hydraulically operated.
3rd set is electrically commanded and electrically operated.
What does the HP Turbine Drive?
What does the LP Turbine Drive?
HP drives the compressor
LP drives the Fan.
(Refer to AOM II 2-10-15 page 4)
What is the purpose of the scavenge pumps?
To retrieve oil from the items being lubricated.
During end start, when the IGN is in auto, at what % of N2 will it fire and how is this accomplished
14% N2 and both igniters are fired automatically.
(Refer to FPMU schematic 2-10-10 pg 3)
What will happen if the shaft driving both the centrifugal pump and the gear pump breaks?
Both those pumps will go off line.