1.5 Power Plant Flashcards
What is the rated horsepower of the engine?
1600 SHP
What is the name of the engine?
Pratt and Whitney (P&W) PT-6 Free turbine engine
What material are blades made of?
Graphite
What direction do blades spin in?
Clockwise when viewed from the cockpit
What are the two main sections of the engine?
Gas generator + Power Turbine
What does gas generator section contain?
1) Intake
2) Compressor section (4 axial + 1 centrifugal stage)
3) Combustion chamber
4) Compressor turbine
What engine section drives the accessory gearbox at the rear of the engine?
Gas generator section
What drives the power turbine section?
Flow from gas generator section
How many stages of turbine are on the power turbine section?
2
What drives the reduction gearbox at the front of the engine? What does the reduction gearbox drive?
- The power turbine section
- Reduction gearbox drives the propeller at the front
Why do the gas generator and power turbine sections rotate in opposite directions?
To minimize gyroscopic effects
What does a reverse flow engine mean on the PT-6A engine?
Air is sent to the rear of the engine and then makes its way through the various stages to the front of the engine.
What does the PMS do?
Controls the engine power output in conjunction with PCL by adjusting:
- Fuel Flow
- Prop blade angle
What was the main components of the PMS?
1) PMU
2) PMA
3) FMU
4) PCL
5) PIU
6) DCU
How can the PMS modes be changed?
Through the PMS push button on the ENGINE panel
What are the two PMS modes?
AUTO and MAN
What is ground idle in PMS Manual Mode? Flight Idle in PMS manual mode? Ground Idle for PMS Auto? Flight Idle for
PMS Manual:
- Ground Idle = 67.5 +- 7 %
- Flight Idle = 67.5 +-7%
PMS Auto:
- Ground idle = min 54%
- Flight Idle = 80%
What should the PCL be set at when selecting the PMS to manual?
At mid-power or lower power setting.
What provides power to the PMU during normal ops?
- PMA which is driven by the reduction gearbox.
- During engine start/shutdown, powered by BATT BUS.
What does the PMS restrict the engine power to on the ground and during TO below speeds of 80 KIAS?
1080 SHP
What is the engine power output above speeds of 80 KIAS?
Linearly increases from 1080 SHP to 1600 SHP from 80 KIAS to 200 KIAS.
What is min ground idle in PMS auto? Normal ground idle?
- 50.7% min
- 54% normally
What is flight idle NG with PMS Auto?
80%
When is PMS idle zero thrust in the air?
At speeds of 120-140 KIAS
What is the flight idle setting controlled by?
The nose WOW switch.