This from a Yank who has never been closer than Honolulu to Australia; but who HAS "shot" quite a few airplanes in flight, at quite a few air shows.
Realizing that I have zero knowledge of your experience, or your "kit"........photographing planes at any air show is a very difficult proposition, even when you're "positioned" perfectly; almost everything is working against you; the subjects are moving fast, they're seldom close, and even the BEST D SLR out there isn't going to give accurate exposures, because it always "sees" more sky than it does airplane ! (That's largely why almost all of the great air show pictures you see were taken by people who have doing it for a looooooong time ! ) ( and have some "serious equipment" )
I know I'll catch a lot of flac saying this, but even hand-holding a 200 mm lens is never going to be any way near as sharp as one taken from a tripod mounted camera. And when it come to tripod mounted cameras........99% of them are going to be on either a pan-tilt head ( whih is useless for tracking anything moving faster than a snail ), or else it's gonna be on a ball head, (which is better, but not much ) If you seriously want to photograph performing planes at an air show, you need a very solid tripod, with a good gimbal head on it; and when you have that.......you need to be as close as possible to "the action".
Assuming you're with me so far, I'll recommend you start practicing up with spot metering, dynamic auto focusing, and the faster the shutter speeds, the better ! Oh........another thing to throughly familiarize yourself with prior to the air show.......how to shoot "bursts" ( hopefully in the 7 to 10 fps category ) if all this seems to ":suggest" a D-4 with a 300 mm / f2.8, it would definitely help !
I have a good friend who was a professional photographer 25 years ago; now that she's retired, her "passion" is racing; so about a year ago, she bought herself a brand new Nikon D 4, a new 400 mm / f 2.8, and an Induro gimbal head; she's now doing some great work; but she tells me that even with the best kit available.......it's a bitch ! getting good pictures of fast moving things takes a lot of time, a lot of practice, a lot of experience, and a BUNCH of "bucks" !
Stupidity: Doing the same thing over and over again and expecting a different result; Albert Einstein