User manual

DodoSim 206 FSX User Manual

Page 59

pilot opens the throttle to begin delivering fuel. The fuel then ignites and literally explodes within the

combustion chamber.

Due to the fact that the starter motor is forcing air in through the compressor section, the exhaust gases

created from the expanding explosion within find it easier to exit through the rear of the engine between

the vanes of the power turbine, turning it as they do so.

As the power turbine (N2) accelerates, so does the compressor stage (N1) due to the volume of gases

being drawn out by the power turbine decreasing the pressure created by the compressor stage within

the engine.

To prevent the gases from escaping back past the compressor stage, the starter must continue to be

applied until such time as the engine has accelerated to a self-sustaining speed. Releasing the starter

button before this point will result in the engine decelerating and prevent the hot combustion gases from

being expelled. The Exhaust Gas Temperature (EGT) gauge will be seen to increase dramatically and

irrecoverably. This is called a “hot start” and can seriously damage the engine.

Once the turbine has reached self-sustaining speed, the starter button can be released and the throttle

advanced to the flight ready position, (after observing any required warm up periods.)

The following procedures assume normal environmental conditions and no wind. Refer to the notes

following the start procedures for information on how environmental conditions and weather effect the

start procedure.

4.1.1.1 Bendix FCU

The Bendix FCU is the simplest to operate of the two and provides less chance of a hot-start due to pilot

error.

Assuming a “cold and dark” cockpit, this is the procedure used to start the helicopter and ready it for

flight:

1. Anti-icing switch to OFF

2. Hydraulic (control boost) switch to ON

3. Control check FREE and CLEAR – move all controls through full range of motion

4. Fuel valve to OPEN

5. Instrument light switch to OFF

6. Generator switch to OFF

7. Direction Gyro & Attitude Indicator switch to OFF

8. Avionics switch to OFF

9. Position lights switch to OFF

10. Pitot heat switch to OFF

11. Caution lights (annunciator) CB to IN

12. Generator field CB to IN

13. Generator reset CB to IN

14. Master battery switch to ON