Category 1 - Aircraft types: Governmental/presidential aircraft (Can be taken anytime)
RAF HS 125 at RAF Linton-on-Ouse by Kevin Martin 1, on Flickr
Category 2 - Close up: Line-up of tails
Italian CH-47's awaiting their fate at Viterbo by Kevin Martin 1, on Flickr
Category 3 - Action: Panning
Swiss Airforce F-18 at Meiringen May 8th 2012 by Kevin Martin 1, on Flickr
Category 4 - Weather: Dark storm cloud backgrounds (Can be taken anytime)
USAF F-15 Waddington by Kevin Martin 1, on Flickr
Category 5 - Angle: Topside - proper topside, roughly over 45 degrees of bank, not just slight.
Spanish Airforce F-18 at Gando AB, Gran Canaria 24.4.2012 by Kevin Martin 1, on Flickr
Kevin
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