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70 Cards in this Set
- Front
- Back
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How much SHP for Q200 w/ and w/o uptrim?
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PW-123D 1950 or 2150 w/ Uptrim
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How much SHP for Q300 w/ and w/o uptrim?
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PW-123 2140 and 2380 w/ uptrim
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How many rotating components on PW123/123D and what are they?
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6
HP Centrifugal compressor HP Turbine LP Centrifugal compressor LP Turbine 2-Stage power turbine |
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How is pressurized oil provided throughout the engine?
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Gear driven oil pump, from the accessory gearbox
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How is heated oil cooled?
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2 ways-
Air/oil cooler in the engine intake duct Fuel/oil cooler (actually a heat transfer - cold fuel vs heated oil) |
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If we had a catastrophic loss of engine oil could we still feather the prop?
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Yes.
There is a reservoir of engine oil in the prop reduction gearbox for use by the Auxiliary feather pump. |
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What drives the Engine accessory gearbox?
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Tower shaft driven by the HP compressor.
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What accessories does the engine accessory gearbox drive?
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F.O.D.
Fuel pump Oil pump DC starter/generator |
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How is the DC started generator cooled?
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Air
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How does the DC starter/generator function?
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Drives the HP compressor for starting up to 60% Nh and then switches to DC generator function
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What engine accessories are driven by the prop reduction gearbox?
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HAP-P
Hydraulic pump (main engine driven) AC generator Prop control unit (PCU) Prop overspeed governor (POG) |
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How is Prop Governor Mode (or forward thrust mode) identified on the quadrant?
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Carets above flight idle to the full forward position of power levers
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In Prop Gov. Mode, what do the power levers control?
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Engine speed by way of fuel scheduling.
In this mode prop angle is controlled by the prop control unit. |
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How is Beta Mode identified on the quadrant?
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From carets above flight idle down to Max Reverse (full aft)
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In Beta Mode, what do the power levers control?
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Engine speed AND blade angle via direct inputs to the prop control unit.
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What prevents the power levers from entering prop governor mode?
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Control lock
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What must happen to bring the power levers below the flight idle gate?
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Gate release triggers must be lifted. These help prevent the lever from being put into ground beta range in flight.
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What happens if the power lever triggers are lifted in flight?
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An aural warning will sound to help prevent entering ground beta range in flight.
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What are the 3 functions of the condition levers?
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Adjust propeller RPM (900-1200)
Manually feather the engine Introduce/Terminate fuel flow to the engine |
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What is the difference between the ECU and the EEC?
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None, they're used interchangeably to confuse us.
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How is fuel scheduling determined by the MFC (manual fuel controller)?
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Combination of Power Lever Angle and pneumatic input (not dissimilar to a fuel injected Cessna/Piper)
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What is the general function of the ECU?
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Receives signal inputs from various systems and works with the Man. Fuel Controller to refine fuel scheduling (more efficient operation).
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Will the engines operate if an ECU fails?
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Yes. The MFC provides enough fuel and pilot control alone for engine operation. However the pilot will be responsible for the automatic functions of the ECU.
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What happens to the engine torque when the ECU fails?
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You will see an 8-10% increase in torque.
This may require splitting the power levers to achieve symmetrical torque. |
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What are the 3 settings for the ECU rating selector?
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**Q200 ONLY**
TOP - Takeoff power MCL - Max Climb MCR - Max cruise **Rating selector system is disabled on the Q300** |
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What function does the ECU rating selector serve?
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Sets appropriate/optimum torque bug for the selected phase of flight.
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The ECU must be set to _ _ _ for takeoff, otherwise a Takeoff Warning Horn will activate.
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TOP
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What are 2 indications that an ECU is either failed or not selected on?
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#1 or #2 ENG MANUAL
caution light The ENG 1 or ENG 2 ECU MODE switchlight shows "MANUAL" in amber, rather than "ON" in green. |
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What automatic functions are lost with an inoperative ECU?
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UHUF
Uptrim (if the opposite engine fails) Handling Bleed-Off Valve (HBOV) automatic operation Underspeed (Np) protection/governing in Beta mode Fuel Scheduling (reverts to manual) |
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When are we concerned with prop underspeed, and how do the ECUs protect us from it?
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Well, always, but for the sake of this question...
Operating in the beta mode on the ground ECUs keep Np above the restricted range (500-780) by adding fuel to increase Nh, thus speeding up the prop. |
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What will cancel the Np underspeed governing?
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Any means of feathering the prop
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What is the HBOV?
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Handling Bleed-Off Valve
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Where does the HBOV source its bleed air?
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The low pressure compressor (P2.5)
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What does the HBOV do?
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Bleeds low pressure compressor air through a pre-cooler, prevents compressor stall and surge conditions, as well as aids in engine noise reduction.
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What is Uptrim?
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When the autofeather system is activated in an engine failure, the system sends a "Power Uptrim" signal to the opposite ECU triggering and increase in power to compensate for the failed engine.
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How much is power increased through the uptrim function?
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10% nominally
(Note that the 10% is above the current power setting, thus a reduced torque takeoff with 88.5% TQ will result in approx 98.5% TQ w/ uptrim. |
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What are the 5 main components of the propeller control system?
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Propeller control unit
Prop overspeed governor Autofeather system Alternate feather system Sycrophase system |
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The Prop Control Unit receives mechanical inputs from the ________ _________s for constant speed operation.
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Condition levers
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The prop control unit receives mechanical inputs from the ________ _________s while operating in Beta mode.
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Power Levers
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What are the 3 feathering methods?
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Automatic - Autofeather system
Manual - Via Condition Levers Alternate - Alternate feather system |
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Where is the PCU mounted?
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Prop reduction gearbox
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How does the PCU work? ************************** |
The PCU regulates oil pressure to a double acting pitch change mechanism inside the prop hub.
From the systems manual: "It controls propeller blade angle by metering engine oil (varying pressure) to one side of a double-acting pitch change mechanism which is opposed by unmetered engine oil (constant pressure) being applied to the opposite side of the same pitch change mechanism." |
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What is metered oil commonly referred to and what meters it?
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Fine Pitch Oil
Metered by the PCU |
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What is unmetered oil commonly referred to as?
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Coarse Pitch Oil
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Fine pitch oil drives the pitch control mechanism to a _________ pitch (________ speed).
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Flat pitch (low pitch)
High speed |
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Coarse pitch oil drives the pitch control mechanism to a _________ed position (________ speed).
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Feathered pitch (high pitch)
Low speed |
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*******************************
How is feather accomplished? ******************************** |
Dumping fine pitch oil.
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In what mode do the engine and prop produce thrust at a constant propeller speed?
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Prop governor mode
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Synchrophase System synchronizes what?
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Propeller speed
Phase angle (approx blade position) |
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Sychrophase must be turned off for what phases of flight?
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Takeoff and landing
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For synchrophase, which prop is the master?
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Left #1
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Where is the synchrophase controller mounted?
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#2 PCU
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True/False
The synchrophase may be left "ON" for RPM/Condition lever changes changes |
False
Turn off, move condition levers w/in 20RPM, turn back on |
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When does the autofeather arm?
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Power levers above 60*
Both engines torque >38% |
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How do you know the autofeather has armed?
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The switchlight will display "ARM" in amber.
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If autofeather does not arm may we continue the takeoff?
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No, takeoff must be rejected
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When will the autofeather disarm?
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1. When an autofeather occurs
2. When the power levers are retarded 3. When the autofeather switchlight is deselected |
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What will trigger and autofeather?
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One engine's torque drops below 28% while the other remains above 38%
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What is the autofeather sequence?
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The SCU will send a Power Uptrim message to the ECU on the operative engine resulting in a 10% torque increase. This is confirmed via the torque gauge and the PWR UPTRIM advisory light illuminating.
After 3 seconds, the autofeather will disarm (light extinguishes) and the SCU will activate the Auxiliary Feather Pump. This will provide coarse pitch oil in the case of a dead engine, and open the Feathering Solenoid Valve in the PCU for 18seconds, dumping fine pitch oil; thus feathering the prop. Successful autofeather is confirmed by observing the Np drop thru 780RPM. Operation of the Auxiliary Feather Pump is also confirmed by illumination of the green Alternate Feather advisory light. |
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The Auxiliary Feather Pump is used by which feathering systems?
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Alternate Feather and Autofeather
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How does the manual feathering system work?
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Placing the condition levers in the start & feather position opens the manual feathering valve in the PCU.
This opens the feathering solenoid valve, thus dumping fine pitch oil and allowing the coarse pitch oil to force the propeller into feather. |
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Where must the associated power lever and condition lever be for the alternate feather system to operate?
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Power lever - Flight Idle
Condition lever - At or aft of Start & Feather This prevents inadvertent activation. |
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How does the alternate feather system work?
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Similar to autofeather:
Opens Feather Solenoid Valve to dump fine pitch oil, and activates the Auxiliary Feather Pump to provide coarse pitch oil in an engine failure, thus feathering the engine. |
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Where is the Propeller Overspeed Governor located?
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Prop reduction gearbox
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How does the Prop Overspeed Governor work in flight (above flight idle)?
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When a certain Np is exceeded, the POG will dump fine pitch oil, moving the prop towards a feather position, thus aerodynamically slowing the prop.
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How does the Prop Overspeed Governor work on the ground (below flight idle)?
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POG has a pneumatic section that will bleed off P3 air (HP compressor air) from the manual fuel controller. Since the MFC uses P3 air for fuel scheduling this reduces the fuel and thus slows the engine/prop down (remember, we're in beta mode).
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What are propeller ground range lights?
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On the left glareshield, they illuminate to indicate the propellers are in the ground beta range. The remain illuminated as long as the power levers are below flight idle.
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What does Beta Backup Protection System do?
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If advancing the power levers above the beta range does not extinguish the ground range lights and the blade angle persists in the ground range, the Beta Backup System will open the Feather Solenoid valve, thus dumping fine pitch oil and increasing blade angle out of ground range.
It will continue to do this to keep the prop out of ground range, and the ground range lights will cycle accordingly. |
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If a loss of oil pressure were to cause the propeller blade to begin to change to a random angle, what will happen?
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The prop pitch change mechanism has a pitch lock feather that will engage and prevent aerodynamic loads from changing the prop more than 1* or increasing prop speed by 2%. This can be overridden by using the alternate feather to feather the affected prop.
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What are the 2 features of the Beta Lockout System?
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Beta Warning Horn - Sounds if power lever trigger are lifted in flight
Revised Beta Backup Logic - Enables Beta Backup regardless of Power Lever Angle The beta lockout system disables below 50ft and when the weight on wheels sensor is triggered, allowing beta range while landing. |
