Gianni,
You need to change your default settings:
1) Start Fllight Simulator as normal. (Don't start the flight Logger yet)
2) Turn your engines off.
3) Go to the file menu and select Save Flight.
4) When you get the save dialog window check the box that says "Make this the default flight"
Next time you start Flight Simulator, your engines will be off. Be carefull as it will also save all your Fuel, Payload and light settings as well.
Hope this helps,
Phil