 The flight lasted for 45 minutes, reaching 50,000 feet in 13.5 minutes.The following year he went on to test the de Havilland Comet, the world's first jet airliner which first flew in 1949.On 23 May 1952 he flew the Comet—now a highly successful export—carrying the recently widowed Queen Mother and Princess Margaret on a four-hour tour around the Alps.