General Aircraft Monospar ST.25 Jubilee

06/23/2025. Remarks by Johan Visschedijk: "The year 1935 saw H.J. Stieger's departure from General Aircraft Ltd, thus Monospar development became the responsibility of F.F. Crocombe as Chief-Designer, with D.L. Hollis Williams as Chief-Engineer and E.C. Gordon England as managing director. Substantially the same as an ST.10, it was fitted with a folding seat for an occasional fifth passenger. Additional cabin windows were therefore necessary and the radio receiver and homing device was standard fitment.

To mark the 25th anniversary of the reign of King George V, type numbers ST.19 to ST.24 were omitted and the new aircraft received both the designation ST.25 and the type name Jubilee. The prototype, G-ADIV, powered by two 90 hp Pobjoy Niagara II seven-cylinder air-cooled radial engines, was sold to Radio Transmission Equipment Ltd. for the further development of its specialized radio but met a watery end in Wigtown Bay a year later. Unlike most small contemporary aircraft, the list price included all instruments, night flying and other primary equipment. The popularity of this idea was such that when production ceased in 1939, 57 had been delivered."