Recurring Guest Characters David Silbey - Cornell University 4 guest appearances Christopher Capozzola - Massachusetts Institute of Technology 4 guest appearances Mitchell Yockelson - National Archives and Records Administration 4 guest appearances David Willey - The Tank Museum, UK 1 guest appearances Christy Campbell - Journalist & Author 1 guest appearances Steve Slater - Pilot & Aviation Historian 1 guest appearances Peter Devitt - Royal Air Force Museam, London 1 guest appearances Simon Jones - Military Historian & Author 1 guest appearances Jeremy Banning - Military Historian 1 guest appearances Nick Hewitt - National Museum of the Royal Navy 1 guest appearances Professor Eric Groves - University of Salford, UK 1 guest appearances