2c black & red postal stationery envelope of Panama with 'CANAL ZONE' overprint (H&G B2) used with CRISTOBAL machine cancel dated OCT 6 1920. Flown on the ill fated first flight between Cristobal and the USA via Kingston, Jamaica with CRISTOBAL C.Z. AIR SERVICE FIRST DESPATCH CANAL ZONE - U.S.A. cds dated 6 OCT at 6 AM. The airplane took off for the first stop in Jamaica and flew over 400 miles in 10½ hours but was forced to turn back due to bad weather. The cover bears the boxed cachet inscribed 'AVIATOR ENCOUNTERED IMPOSSIBLE WEATHER CONDITIONS NEARING JAMIACA COMPELLING RETURN. MAIL RE-DISPATCHED BY STEAMER'. Addressed to WASHINGTON, USA. A fine example of the rare early flight. Ex Osprey. The definitive 6 page article on the flight also accompanies. (Muller #2, rated 10,000pts)