In my opinion there should be the possibility to assign a hotkey to the action of starting the engine of a helo as it won't work in the advanced flight model to just start rising collective to get the engine started.
I especially noticed this since i started using a joystick so I always have to switch back to my mouse to start the engine of my helicopter.
I thought about this being like the enable/disable auto-hover by a simply pressing a button.
Have been there for a while. I believe since the Helicopter DLC in the stable.
Configure -> Controls -> Common -> Engine on/off
you can also simply hit the ascend key (shift by default I believe) and the engine will also start automatically if it was turned off
Not in the advanced flight model and not if you are flying with a joystick... Nevertheless as St.Timmy said there already is such an option so the issue could be closed... But i don't have the permission to do that