THE flight trials programme of the Skyvan is based on achieving a Group C (temperate category) Certificate of Airworthiness, within a period of six months after the production aircraft's first flight. To achieve this goal full use has been made of the prototype aircraft both in its original piston engine form and in the developed form with Astazou turboprop engines fitted. The original prototype Skyvan (the version fitted with Continental piston engines and designated the Mk. I) flew during the period January to May 1963. It was then modified by fitting Astazou turboprop engines, re‐designated the Skyvan IA and flew again in October 1963; it is still flying and continuing with development trials associated with the clearance of the production aircraft. The production aircraft to be known as the Skyvan Mk. II will be fitted with the more powerful Astazou X engines and will operate at a higher all‐up weight than is possible on the Skyvan I. It is scheduled to fly in the last quarter of 1965 and certification is expected in early 1966.