This first production ST-28, first flew in December 1975. The Canadian Saunders Aircraft Company had moved from Quebec to Gimli, Manitoba in 1971 to manufacture ST-27 regional airliners, which were twin turboprop conversions of second hand De Havilland Herons. The ST-28 was a new-build, developed and improved version of the ST-27. However, progress with testing towards certification and series production, with no firm orders, proved too much of a financial strain. The withdrawal of Provincial Government support funding in 1976 finally caused the company to shut down.