Powerplant Flashcards
Normal TO SHP
4580
MTOP SHP
5071 SHP
PEC stands for
propeller electronic control
WHen does the DC starter generator convert to a generator
at 50% NH
Whats on the engine accessory gear box?
dc starter gen
pma (permanent magnet alternator) - provides power to fadec
oil pump
fmu (fuel metering unit)
What does the PMA do?
primary source of power to FADEC, independent coils provide power to individual channels of FADEC (2), functions above 20% NH, ess busses provide power below 20% NH and during PMA malfunction
What is on the prop reduction gear box?
AC generator (oil cooled)
Hydraulic Pump
Pitch Control Unit (PCU)
Prop overspeed governer (POG)
What do the prop levers control between flight idle and max?
initiate fuel demands
What is prop constant speed governed range?
Between flight idle and firewall
What is beta range
disc to flight idle
What is prop constant reverse speed governor range
max/rev to disc
When is the propeller ground range light on?
power levers between max reverse and flight idle
Limitation on MCR power rating
do not use below 10,000 feet or in icing conditions
What does the FADEC do?
Controls fuel scheduling controls various engine bleed valves NH overspeed protection controls automatic start sequence supplies voltage to propeller electronic control (pec) monitors and detects faults
What does the RDC NP switch do?
Pressing the switchlight prior to advancing cond levers to max 1020 for landing, will keep the props at 850 NP for purposes of noise reduction.
What does the MCL button do?
Gives an extra 3% TORQUE for climbing with the condition levers pulled back to 850 RPM
What does the MCR switch do?
After level-off the MCR rating switch is pushed when cruise power is called for (cond levers will already be at 900)
“pushing the MCR switch will result in a max cruise power rating at 900”
What does the event marker button do?
will capture and store pertinent system data for maintenance when pressed after and anomaly
What does ATPCS stand for and do?
Automatic Takeoff Power Control System. Automatically armed for takeoff resulting in an uptrim of power in case of engine loss (10%), limited up to MTOP
When does ATPCS arm?
when both engine are equal to or above 50% torque and both power levers are at a “high” angle
The ATPCS provides auto uptrim when
torque on failed engine drops below 25%
What do the prop counterwheights do?
gives the blade a natural twisting moment towards coarse pitch (feather)
What does POG stand for?
propeller overspeed governor, feathers prop in event of an overspeed, driven by prop reduction gear box
What does the auxiliary propeller feathering pump do
automatically feathers prop or manually with alt feather switch, DC motor
What does the automatic synchrophase system do
reduced prop noise, compares right prop (slave) to the left prop (the master), does not operate during takeoff (props at 1020)
What does the pcu do
the pcu increases the pressure of fine pitch oil to move the propeller pitch
When will the prop ground range lights illuminate?
power levers are moved aft of the flight idle gate to indicate that prop blade angles are in the ground range of operation
How is the autofeather system armed?
both PLAs above 60 degrees
both torques above 50%
When does the autofeather work?
torque on failed engine drops below 25% for 3 seconds
If you don’t get A/F ARM below __ kts then ____
80 kts then abort
Describe engine ignitor system
each engine ignition system has one exciter and two igniter plugs in the combustion chamber, activated and deactivated automatically by FADEC during start, flameout or sure, igniters are inactive during normal engine operation
Describe the engine start system
When start switchlight is selected the starter gen rotates the NH compressor through accessory gearbox, at 8% NH the FADEC commands ignition on and schedules fuel flow, the cond lever must be moved to start & feather position at first indication of NH, only on igniter is commanded on to check for faults, if no ITT rise of 20 degrees after 8 seconds, second igniter is commanded on and fault is logged, at 50 % NH FADEC commands ignitors off, and allows engine to accelerate to 64.2% at DISC position, SELECT switch release to center position, START switchlight goes out, up to 50 seconds later, SELECT segment of start switchlight goes out.
How long without ignition until the start is considered a no light off?
16 seconds
FADEC GROUND START PROTECTION
no ignition within 16 seconds of fuel flow (no light off)
ITT limit of 920C exceeded (hot start)
50% NH not reached within 70 seconds (hung start)
FADEC In-flight start protection
No FADEC abort functions, both igniters commanded on, In-flight status is sensed 75 KCAS or WOW if airspeed invalid
