The Flying Machines book set pits a Fokker EIII Eindecker against an Airco DH2 'pusher' plane (meaning that the propeller was at the back of the aircraft.) Because of the pusher configuration, the DH2 has a flexible forward firing gun - a novel addition to the Ace of Aces system. The game also provides statistics for other early-war German aircraft and Allied pusher aircraft which may be played using this set.Flying Machines includes a different variety of maneuvers than was used in the Powerhouse and Handy Rotary books. This makes for interesting match-ups between the sets.Ace of Aces Series: Ace of Aces - Handy Rotary Series Ace of Aces - Powerhouse Series Ace of Aces - Flying Machines Ace of Aces - Balloon Buster Ace of Aces - Handy Rotary Deluxe Edition Ace of Aces - Wingleader Ace of Aces - Jet Eagles - BoardGameGeek