That was all kinda weird. There had to be a couple hundred air strips just in Turkey.
I'm sure that was the plan while they were circling.
I mean, if his supporters can make Ataturk safe before he runs out of fuel, then that's where he goes (which is what happened). Otherwise, he lands at some friendly air field, refuels, and figures out what to do next.
The plotters' mistake was not to grab him at his vacation spot (Marmaris, on the Mediterranean). Erdogan should have been the first outsider to learn of the coup, at gun point or from virgin #1.