Propulsion is provided by a propeller driven by a pusher engine mounted at the empennage. Propulsion is provided by a three-blade propeller driven by a pusher engine mounted on empennage. Stage separation is accomplished with explosive bolts and a pneumatically actuated pusher system. Foot-launched powered hang gliders are powered by an engine and propeller in pusher configuration. Articulated buses can be of "pusher" or "puller" configuration. The engines face rearward in a pusher configuration. Some Model 102 outboards had a propeller, gaining the moniker of "The Barge Pusher". Reusable separation collets and a pneumatic pusher system separates the stages. Stage separation occurs via reusable separation collets and a pneumatic pusher system. The engine is certified for use in either tractor or pusher configuration installations. These aircraft were distinctive because of their canard configuration, winglets and pusher propellers. The flat plate of propellant formed a cigar-shaped explosion aimed at the pusher plate. This helps keep the pusher plate cool. At that point spalling may occur damaging the pusher plate. Fat Man used an aluminium pusher.