09/30/2011. Remarks by Johan Visschedijk: "SFERMA (Société Française d'Entretien et de Réparation de Matériel Aéronautique, French company for maintenance and repair of aeronautical material) was formed in September 1949. It became a subsidiary of Sud-Aviation and subsequently it expanded its activities to include the modification and conversion of aircraft, the overhaul of low-powered gas-turbine engines and the manufacture of aircraft spares and components, and servicing equipment, while it undertook considerable work for airlines and the Air Ministry.

It became engaged in the maintenance, conversion and modernization of Beech C-45 and 18S aircraft, and in this connection SFERMA was entrusted by the Technical Department of the French Air Ministry with the conversion of two Beech D18S aircraft to serve as a test bed. The aircraft were re-engined with two Turboméca Bastan turboprop engines, driving Ratier-Figeac three-blade variable-pitch airscrews, the tail fins were enlarged and the tail wheel leg was extended.

The first prototype was flown on September 18, 1958, registered F-ZWVO, after fifty trouble-free hours of flight testing by SFERMA, it was handed over to Compagnie Generate des Turbo Machines at Marignane for a series of tests designed to develop a control system. In December 1958 it was handed over to the Air Ministry at the CEV (Centre d'Essais en Vol, Flight Test Center) in Istres, while the second aircraft was delivered in 1959. Although series production was planned, no further aircraft were produced."