17 April 1913 (England/Germany): Briton Gustav Hamel lands after a non-stop flight of 4 hours and 18 minutes from Dover, England, to Cologne, Germany in a Blériot XI.
17 April 1921 (USA): Aviation meet at Oklahoma City, Oklahoma.
17 April 1926 (USA): Western Air Express starts its service between Los Angeles and Salt Lake City.
17 April 1969 (USA): USAF Maj. Jerauld Gentry pilots the Martin X-24 “Lifting Body” research aircraft on its first free flight.
17 April 1970 (England/France): A Sikorsky CH-53D “Sea Stallion” helicopter flies between London and Paris to demonstrate that modern helicopters can provide reliable inter-city services.