I shoot in RAW, then convert in Photoshop........only time i would shoot in JPEG would be when i need a fast multi shoot. I use a Nikon D300, and find my best lens for ground to air stuff is the 70-300 vr.
Photos: Canadair CL-600-2B16 Challenger 601-3R Aircraft Pictures | Airliners.net
BUt i use a 55-200 vr for air-to-air work.
Photos: De Havilland DH-82A Tiger Moth II Aircraft Pictures | Airliners.net
Cheers