Well, based on my limited knowledge, the minimum focal length of lens has got to be 300mm, preferably a zoom so that you can zoom out a bit for the Black Knights formation and then, zoom in for the individual planes or choppers.
As the action would be pretty fast, the AF for your lens has got to be fast enough to focus, track and fire off.
In the past Airshow and the last Airforce open house, I used a zoom up to 300mm - got to crop quite a bit. Better to crop than not able to keep the object within the VF. :bsmilie:
I will try to see if I can post an example of the kind of result I got.
IMO, tripod or monopod are of not much use as your movement would be too restricted. Dunno if others would agree with me.