Powerplant Flashcards
What type of engines does the LR60 have?
How much thrust is produced at sea level?
What about with APR activated?
This aircraft has two PW305A turbo-fan engines that produce 4600lbs of thrust each at sea level temperatures up to 26.6°C or with APR activated 4600lbs at sea level temps up to 33.9°C
What type of air pressure does the Fan section produce? What is the airflow bypass ratio on a standard day @ sea level?
Low pressure @ 4.5:1 bypass ratio
Which engine indicator displays primary thrust? Which DC BUS powers it? Will it continue to operate in an EMER BUS mode of operation?
N1 indicators
Left and right DC BUS 2
Yes, it is part of the final 4 during EMER BUS operations and receives back up power from EMER BATT 1
How is N1 speed measured?
Measurements are completely electronic except 1 cable connected to the N1 spool.
RPM is measured by two induction type sensors mounted at the end of the LP shaft exposed to a toothed wheel mounted on the end of the LP shaft these sensors generate a frequency proportional to the rotation of the shaft.
What portion of the engine is always heated regardless of Anti-Ice systems?
The spinner
What is the purpose of the EEC (Electronic Engine Computer)?
Computes and Controls fuel introduced.
Controls (opens and closes) Variable inlet guide vanes (VGV) to protect against compressor stalls.
What is the FADEC?
FADEC is the total control system which includes the Thrust Levers, EEC (Electronic Engine Control) which computes fuel and the HFCU (Hydromechanical metering unit) which meters fuel.
Where does the EEC (Electronic Engine Computer) receive its power supply from?
DC power is supplied to L&R channel CH.A & Ch.B from the PMA (Permanent magnet alternator mounted to the aft side of the AGB (Accessory Gear Box)
Is it possible for the aircraft batteries to power the EEC (Electronic Engine Computer)?
Yes, if N2 drops below 52% or the PMA (Permanent Magnet Alternator) volts drop below 16VDC EEC will automatically switch to aircraft electrical system without indication to the pilots.
With the starter light on what does this indicate?
Starter Relay is closed and the starter is engaged
How many fuel nozzles are there per engine?
24 total
(2 hybrid active at 335psi during start and
22 active at 445psi during start)
Explain the Engine start sequence
Starter switch placed into start GCU closes Motive Flow Valve Ignition light on @6% N2 Ignition light extinguishes @40% N2 Starter extinguishes @45% N2
What are some of the different FADEC issues experienced during start up? What procedure should be used if experienced?
No Ignition light
No Fuel Flow indication
Hung start
Proceed to Amber tab 8 in QRH
FADEC automatic Ignition system
Above PA 20,000FT with thrust levers cut off, then placed to position idle.
If start happens ignition will terminate at 40%N2
Below PA 20,000FT with thrust levers at position idle or above if N2 drops below 40%
How are the TR’s (Thrust Reverses) controlled and actuated?
Electronically controlled and Hydraulically actuated
What conditions must exist in order to deploy TR’s (Thrust Reversers)?
Circuit breakers in
Both squat switches
Hydraulic pressure
Thrust reversers both in Idle
When must you be out of reverse and into Idle with Thrust reversers deployed?
@ 50kts
Can you get an TR unlock without engine power being reduced to idle and without a T/O horn?
Yes with Secondary latch unlocked.
Is it possible to deploy both and use both TR’s during single engine operation landing?
Both TR’s may be deployed, however, the throttle balk solenoid limits the TR on the operational engine to idle unless both TR deploy lights illuminate
As throttle is advanced for take off what lights on the annunciator glare shield panel will extinguish?
Both green (TR ARM) lights
What will happen if TR deploy lights come on after T/O?
FADEC will bring thrust to idle on that engine.
Auto Stow sequence will initiate (Green TR ARM light will flash during autostow signaling hydraulic pressure is being applied.
Both White and Amber ENG CMPTR lights will illuminate
All 3 TR lights will illuminate
What happens when you pull either T-Handles (5 things)
Closes shut off valve Closes Hydraulic valve Closes bleed air Sends signal to backup shut down solenoid in the FCU Arms the Halon Bottles
With APR armed when will APR activate?
N1 differs more than 15%
N2 differs more than 7.5%
N1 differs more than 4% with power decreasing that engine at >5%/sec
N2 differs more than 2% with power decreasing that engine >2%/sec
