Biplane

You must have been the gent in front of me, then. Sigma 150-500? I find a monopod helps a lot ( but can also be a hindrance at times!). Shoreham is always difficult to get a good shot after about 2pm as the crowd line faces west. I also binned a large proportion of pics, but that's the fun of digital, once you've got the gear all the pics are free to take.
Dave

Actually no, I wasn't at the airport at all but out on the balcony at a private house about 2 miles from the airport in Lancing. View not obstructed by crowds at all, though often by the eaves of the house! Not a zoom, but a fixed focal length mirror lens I had just bought and was trying out for the first time, Opteka. I believe.