Sorry another question,
What does the "push and start" option precisely do? Searching the forum it determines the exact request that is asked to ground if contacted right?
Just out of curiosity how should this work with a small GA plane without external power and APU in real life? Would you first get ground approval for engine start so that you have power for GPS etc? Or would you just get clearance on battery and after that start engine (and have a longer time between clearance and take off)? Are there rules on how long after clearance you are expected to start to taxi and take off?
Best Marcel