Although never shot down, he once survived a mid air collision with his 74 Sqn colleague Sydney Carlin, nursing his crippled aircraft to ground level before climbing out of the cockpit and jumping clear as it crashed. Caldwell fought inconclusive dogfights with German Aces Werner Voss and Hermann Becker. A natural pilot with excellent eyesight and a talent for finding enemy aircraft, Caldwell's weakness was that, as a poor shot, he frequently was unable to destroy the aircraft he engaged—a flaw that stopped him joining the ranks of top Allied aces in which he moved. He knew James McCudden, flew with Albert Ball in 60 Squadron and commanded Mick Mannock in 74 squadron.