In reply to NathanP:
I took my G9m1 and G9m2. If there had been a lot more aircraft then I may have fired off a few shots with my original G9.
I have no doubt that the original G9 would have performed just as well however I had a new toy which had Phased Detection, so I stayed with that.
I put the camera into auto focus and had it concentrate it's attention around the middle of the frame. Not sure if this was wise as it's quite hard keeping a fast moving subject in the viewfinder let alone ensuring that it sticks into the center of the viewfinder.
Maybe next time I'll use the entire image area to focus with.
I did not go with the idea of pre focusing because I could not guarantee what to focus on. There were too many variables.
I do use the pre focus method when my quarry can be predictably relied on to be in the same spot.
I never even considered Back Button focusing. I think, with the computational grunt under the hood, Back Button focusing is consigned to the history books.
Just need to improve my panning technique.