@SadBucket said in Question about when to contact ATC for clearance if avionics are turned on after engine start in the Bonanza:
Didn't realize you needed clearance to start a small piston in EU, sounds absurd to me with the amount of training flights starting simultaneously at my home airport.
You usually don't, AFAIK. At least in Germany, even at bigger airports, you usually just fire it up. If you have a ground crew, a marshaller etc., that's something you'd have to coordinate with them, not with ATC.
At smaller, uncontrolled airfields, it's generally your responsibility to have a clear prop area (we don't yell out the window, though )