The Yeti Airways (subsidiary Tara) fly into Lukla, using the Twin Otter and Pilatus aircraft.
These aircraft have a new engine startup function: when initially placed, the propellers are stationary. The B key is used to start up the engines realistically. It will also stop a running engine. Please read the model description for full information.
There is a driver rule available to start or stop the engines in AI, the Aircraft Engine Start Command, kuid2:60238:89994:1