Great shots!
I always use shutter priority for my shots. I use 250 for props and 500 or above for jets. If you are taking shots of aircraft taking off or landing then use 250 for jets as this will blur the background and give more of an impression of speed. Panning with the aircraft is essential for this to work well.
Hope this helps.
Phill

http://www.outflankeduk.com – my website