South Africa 1931, Aug 5 Windhoek  cds on South West Africa Airways First airmail cover franked with 30d. mixed franking of 1931 Airmail 3d & 10d bilingual horizontal pairs SG 86-87 ; GV pictorial issue 2d. Pair .S 111 all  tied by Lugpos Windhoek airmail cachet (no date) arrival  Keetmanshoop same day cds on back.