DHC-6-300 Turbine Engines

• PT6A-27  /  PT6A-34
• Pratt & Whitney
• Reverse flow, annular combustion, free turbine engines.

• 2 turbines in each engine - 
•   - 1 Compressor turbine (driving the compressor)
•   - 2 Power turbine (driving the propeller)

• 1. Intake (reverse flow)
• 2. Compressor
•   --3 Axial
•   --1 Centrifugal
• 3. Combustion chamber
•   -- Annular (means circular)
• 4. Compressor Turbine (drives the compressor section)
• 5. Power turbine (drives propeller)
• 6. Exhaust (reverses flow again)

Between the compressor turbine and the power turbine.

In the PT6, the power section and compressor section are not connected (free)

600 PSI

600 PSI

1 chamber (annular)

2 per engine

• 14 fuel nozzles per engine - 
•   - 10 primary
•   - 4 secondary

• 4 fire detectors per engine - 
•   - 2 front, activate at 450 degrees (power section)
•   - 2 rear, activate at 300 degrees (compressor section)

40 PSI

You have 8 minutes before engine quits

The secondary fuel nozzles did not engage / failed to ignite & / or engine stops accelerating all together for whatever reason

Mobile Jet II

• Oil tank quantity - 2.3 US gallons
• Oil useable - 1.5 US gallons
• Oil normal quntity - 1-2 quarts low

Gas generator speed

Propellor speed

stationary compressor blades

8 per engine - they measure the temperature of the air.

3 per engine