Dean served in the British Military for 32 years, flying Lynx, Apache and MQ-9 Reaper, on multiple operational tours. As a Commissioned Executive Officer and Flight Instructor, Dean managed complex programs and introduced new equipment into service for both British Army and later the Royal Air Force. His final tour was on exchange with the USAF, where he was an MQ-9 Reaper instructor with Evaluator Status (SEFE).