Turboprop on 20 September 1945. From their experience with the Trent, Rolls-Royce developed the Rolls-Royce Clyde, the first turboprop engine to be fully type certificated for military and civil use, and the Dart, which became one of the most reliable turboprop engines ever built. Dart production continued for more than fifty years. The Dart-powered Vickers Viscount was the first turboprop aircraft of any kind to go into production and sold in large numbers. It was also the first four-engined turboprop. Its first flight was on 16 July 1948. The world's first single engined turboprop aircraft was the Armstrong Siddeley Mamba-powered Boulton
Joan Vickers, Baroness Vickers on 25 March 1904 and became one of their partners at their office at 4 Moorgate Street. At the end of the First World War, all the German stockbrokers were forced to resign. In 1917 he set up his own firm, Vickers, da Costa, which counted Sir Winston Churchill among their clients. Her brother, Ralph Vickers was later Senior Partner of the firm. Vickers was educated at St Monica's, Burgh Heath, Surrey, and in Paris. She was trained as a Norland Nurse, working in the Margaret Macdonald and Mary Middleton Hospital, Notting Hill and was active in politics in Battersea