Mystery Airplane: July 2015

The de Havilland DH 114 Heron, which first flew at Hatfield on 10 May 1950, proved adaptable to stretching and engine changes. Initially powered by four de Havilland Gipsy Queens of 250 to 340 hp, it was later rebuilt with 260 and 340 hp Lycomings. The ultimate modification came in 1969 when Saunders Aircraft of Gimli, Manitoba, reconfigured a Heron Mk. II with a lengthened fuselage, a reengineered wing, and a pair of 715 hp P & W PT -6A turboprops. The fuselage stretch was eight feet six inches to increase passenger capacity to 23. David Saunders, who had been connected to the ill fated Avro Arrow, spearheaded the ST-27, which was designed for commuter operations.

The prototype ST-27, CF-YBM-X, originally Heron #14058, made its maiden flight on 28 May 1969. Canadian Department of Transport approval came in 1971. A dozen conversions of Herons were completed and sold to airlines in Canada and Colombia, the largest operator being City Express, based at Toronto Island Airport. Eventually, a shortage of Heron airframes, financial problems, and failure to get an American Approved Type Certificate ended development. Saunders shut down in December 1975.

I photographed C-FJFH at Hamilton, Ontario, in June 1986. Built as a Heron Mk. II (#14097) in March 1956, it was delivered as G-AOGU to Cambrian Airways. After service in Germany with Sudflug as D-CASI, it moved to Denmark as OY-DPO. Saunders Aircraft bought the Heron in March 1973 and converted it to an ST-27. Use by Air Atonabee and City Express followed. It was deregistered by 1999.

This month's winner is Tim Verhoeven of New Prague. Brian Danielson of Litchfield came close, thinking it was the one off Saunders ST-28 of 1974, C-FYBM-X, which did not reach production.

On to Oshkosh! Blue skies and tail winds.