South West Africa 1931 Pilot Signed Imperial Airways Xmas

SWA: 1931 Imperial Airways London to Cape Town Special Xmas flight PIETERSBURG to WINDHOEK. Printed registered envelope franked Airs 4d & 1/- clearly tied despatch cds 19 DEC. Additional cds alongside & PILOT SIGNED E.H. ATTWOOD. On reverse are excellent postmarks of departure, transit Johannesburg 21 DEC & the special bilingual Windhoek - Kimberley Air Mail arrival cds 21 12 31. Fresh, VF, scarce.