Worldwide Stamps and Covers.

1927 cover franked with 5m and 10m, endorsed "By Swiss Aeroplane to Nairobi" and "Carried by Aeroplane from Khartoum by kind permission of Capt. Mittelholzer", also signed across the stamps "W.Mittelholzer", little staining, otherwise fine (Walter Mittelholzer was a Swiss aviation pioneer, active as a pilot, photographer, travel writer and also as one of the first aviation entrepreneurs. He made the first North-South flight across Africa. Mittelholzer started in Zurich on December 7, 1926, flying via Alexandria and landing in Cape Town on February 21, 1927)
Estimate: $500