The Flying Triangle.... -- The Avro 707, a single-jet flying model to test the possibility of future multi-jet bombers, on show here at the opening day of the exhibition of new British aircraft organized by the Society of British Aircraft Constructors. The Avro 707, manufactured by the Armstrong Siddelay Motors, limited, has swept-back wings which form the shape of an equilateral triangle. September 7, 1949. (Photo by Pictorial Department);The Flying Triangle.... -- The Avro 707, a single-jet fl