South Africa 1937 Empire Airmail First Flight "All-Up" 1½d Rate

1937 EMPIRE AIR MAIL SCHEME: First flight of the "All Up" mail Durban to England. Cover franked Gold Mine 1½d tied by Durban machine canceller JUL 1 1937, last day of mail acceptance for the flight departing 4th July. The cover is annotated "First Flight by Flying Boat on new Imperial 1½d Airmail Service between South Africa and England." Straightline violet cachet Per R.M.A. Corsair. VF, nice clean cover. The Flying Boat Corsair was commanded by Captain HWC Alger for this flight.