Bristol 138
The Bristol Type 138 High Altitude Monoplane was a British high-altitude research aircraft developed and produced during the 1930s. It holds the distinction of setting nine separate altitude world records, the ultimate of these occurring on 30 June 1937, during a 2¼-hour flight flown by Flight Lieutenant M.J. Adam, in which he achieved a record altitude of 53,937 ft (16,440 m).