10/31/2010. Remarks by Walter van Tilborg: "The two-seat Sport Mk.1, also referred to as the Pup, made the first flight on October 2, 1966. The aircraft was designed and constructed by Harry Wellington of Ontario, California, USA, and built over a two-year period. Initially it was flown with an 160 hp Kinner R-540-1 five-cylinder air-cooled radial engine, but later re-engined with a 220 hp Continental W670 seven-cylinder air-cooled radial engine. The aircraft remained active for many years and was still on the register in 2010."