What Is A Departure?
Well, I know what an in-flight departure is (stimulating is one word for it). But how is 'departure time' defined for airline ops?
Not takeoff, I'm sure, but presumably some point before that. Is it boarding gate closed, doors closed, engine start, push back, ATC clearance to taxy, what?
And is it the same definition for all airports/operators/countries?
I suppose the same question could be asked about 'arrival'.
Just curious.