Oral 2 Flashcards
If you are flying along and get an AC BUS annunciator, what has happened?
You lost the associated AC bus
While flying the left GEN TIE OPEN illuminates, what has happened with regard to the center bus?
The left generator bus has been isolated from the center bus.
What powers the cockpit emergency lights?
The Battery or Duel-Fed bus
What is normal generator voltage?
28.25 VDC
With the Battery Switch OFF and the BATTERY BUS switch in EMER OFF, what should the BATTERY BUS voltage read?
0 VDC
What does a flashing EXT PWR annunciator mean?
The GPU is electrically disconnected from the aircraft.
What must the battery voltage read to perform a GPU start?
at least 20 VDC
What is the min battery voltage for a battery start?
23 VDC
What will happen if you forget to turn off the starter, during a start, and try to bring a generator online?
Nothing. You cannot bring a generator online with the start on.
What does the crossbreed valve do during an engine start?
It prevents compressor stalls. The axial flow compressor produces more pressure, at low RPM, than the centrifugal compressor can handle.
When should engine oil be checked to ensure an accurate reading?
Within 10 minutes after engine shutdown.
MAX ITT for engine start.
1000C for 5 seconds
If I’m flying along and I notice that the oil pressure on one of my engines is less than 60 psi, what should I do?
Oil pressure of less than 60 psi is unsafe. An engine shutdown should be considered.
If I’m flying along and I notice that the oil pressure on one of my engines reads between 60 and 90 psi, what should I do?
Oil pressure between 60 and 90 psi is undesirable: tolerate only for the completion of the flight. Do not exceed 62% power.
What is the minimum oil pressure at idle?
60 psi
What is the maximum torque for 20 seconds?
156 %
The compressor section on the PT6A-60A has what type of compressors?
One, 3 stage axial flow and one centrifugal
How many turbines are on the PT6A-60A engine.
2 power turbines and 1 compressor turbine
Is the shaft that drives the gearbox and prop the same shaft that drives the accessory case on the back of the engine?
NO. It is a split shaft engine.
At what torque setting doest the engine auto-ignition come on?
below 17 % torque
During preflight, you notice the engine is 5 qts low. What should you do?
Start the engine and run it for 2 minutes and recheck the oil.
Can you mix different types of oil in the engine?
NO
If you are sitting in the aircraft with the battery off and you push the FIREWALL VALVE, what happens?
The fire extinguisher will arm.
Which bus powers the engine fire detection system?
Triple Fed Bus
When will the auto-feather system arm during takeoff?
When the power levers are advanced beyond a position corresponding to 88% (87-89%)
What governor controls the prop speed in the event the prop becomes fixed pitch?
The Fuel-topping Governor
What governor regulates the prop RPM in reverse?
the Fuel-topping governor to 95% of selected RPM.
The overspeed governor governs at 104% of max N2 or prop RPM. This is approximately what RPM?
1768
Prop pitch when feathered?
79.3
Prop pitch at flight idle?
12
Prop pitch in ground idle?
2
Prop pitch in reverse?
-14
If the prop becomes fixed-pitch, the Fuel-topping Governor will regulate RPM (N2) at approximately how much higher and lower?
6% higher than selected by the governor and 5% lower for minimum speed.
