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
Tourism in the Caribbean sugar, and bauxite were no longer competitively priced with the advent of free-trade policies. Encouraged by the United Nations and World Bank, many governments in the Caribbean encouraged tourism beginning in the 1950s to boost their third-world economies. The Caribbean Tourist Association was founded in 1951. Tax incentives encouraged foreign development of hotels and infrastructure, cultivated by newly formed tourism ministries. Regular non-stop international airplane flights in the 1960s made vacations to the Caribbean more affordable and increased the number of visitors. Visitors from Europe could travel there in eight hours, whereas it used to take three weeks by ship.