Air Mail cover 1926 (18 Dec.) London - Cairo - Khartoum - Kenya Experimental Flight envelope, carried by Air Commodore Weir to Cairo (signed and inscribed on reverse, he later lost his life in the R-101 Airship disaster), showing on front a good strike of the unframed "Carried by the Airline between Khartoum and Kisumu, Kenya Colony" h.s. in violet, signed by the pilot for the Khartoum - Kenya leg, Captain T.A. Gladstone; a violet oval cachet "H.E./THE GOVERNOR" applied on arrival and bearing Kenya and Uganda 20c. applied and cancelled (14.2) in Nairobi. Only about ten such covers are thought to exist. Photo