12/31/2013. Remarks by Walter van Tilborg: "The Defiant push/pull four/five-seat light sport aircraft was the first twin-engine design of Burt Rutan and the prototype was built as a proof of concept for the projected Defiant 60 (intended for certification) with two 180 hp Lycoming O-360 engines.

The first aircraft, built as the Model 40 Defiant and registered N78RA, was first flown on June 30, 1978. Initially it had two 150 hp Lycoming O-320s, was then re-engined with two 160 hp IO-320s and in 1986 it received two 180 hp Lycoming O-360s. Dimensions of this first Defiant included a 28 ft 10 in (8.79 m) wingspan.

A second Model 40 Defiant was built, in co-operation with Rutan, by Fred KellerThis had two 150 hp engines, an O-320-E2A in the nose and an O-320-A2Bin the rear. Furthermore it had a new longer span canard foreplane with new airfoil and ailerons, an increased 31 ft 5 in (9.58 m) wingspan and modified inward canted winglets. This aircraft served as prototype for the homebuilt version, the Model 74.

The Model 74 Defiant became available for amateur construction. Plans were marketed via Rutan and examples of the Defiant were built with engines in the 150-180 hp range and both the Lycoming O-320 and O-360 series were favorite. The first plans-built aircraft was completed in 1985 and this aircraft had two 150 hp O-320s. Two aircraft were reported built with two Ford or Javelin/Ford V6 modified car engines.

Some twenty Defiants were completed worldwide, including Norway and the UK. The pictured aircraft was built by Michael J. Cardinale of Palm Bay, Florida, USA and was registered N49MC on April 18, 1986. It flew the same year, powered by two Lycoming O-320 engines. The aircraft was recently cancelled, June 12, 2013."