R21 6 July 1931 First new 1931 engine, passed final inspection. 2,292 hp (1,709 kW). Installed in S.6B, S1595, for first flight 29 July.
R15 22 August 1931 Flown in S.6B S1595.
R29 13 September 1931 Installed in S.6B, S1595, for the Schneider Trophy Contest. Aircraft flown by Flt Lt John Boothman won the Schneider Trophy aircraft.
R27 29 September 1931 Fitted in S.6B S1595 (the Trophy-winning a
ircraft), and gained the air speed record at 407.5 mph (655.8 km/h).