Details
Air Mail cover 1927 (Feb.) Experimental Survey Flight Khartoum to Kisumu by Captain Gladstone (signed on face), an envelope showing a faint strike of the scarce "Carried by the airline between/Khartoum and Kisumu Kenya Colony" cachet (improved with pencil), reverse bearing Kenya and Uganda 10c. (2) cancelled at Nairobi (14.2)
Further details
Note: Gladstone's original plane was wrecked on the Nile, and an R.A.F. Fairey placed at his disposal to complete the flight