Aerial refueling craft was eventually modified by Airspeed to Cobham's specification, for a non-stop flight from London to India, using in-flight refueling to extend the plane's flight duration. Meanwhile, in 1929, a group of U.S. Army Air Corps fliers, led by then Major Carl Spaatz, set an endurance record of over 150 hours with the "Question Mark" over Los Angeles. Between June 11 and July 4, 1930, the brothers John, Kenneth, Albert, and Walter Hunter set a new record of 553 hours 40 minutes over Chicago using two Stinson SM-1 Detroiters as refueler and receiver. Aerial refueling remained a very dangerous process
Vogt Lo-150 United States. A.J. Smith won the US Nationals flying an Lo-150 in 1961. Harold Jensen flew an Lo-150 in 1962, winning the Barringer Trophy. Vogt Lo-150 The Vogt Lo-150 is a West German high-wing, single seat glider that was designed by Alfred Vogt and produced by the Wolf Hirth Company. The Lo-150 was developed from the wing span aerobatic Vogt Lo-100 as a performance cross country sailplane. The Lo-150 is constructed from wood, including its wooden monocoque fuselage. Its span two-piece wing employs a Clark Y airfoil and incorporates flaps for glidepath control. Early examples use a take-off dolly and