An aeronautical engineer, she also has a place in aviation history as the inventor of a device which saved many lives. Fitted to Spitfires and Hurricanes, the invention prevented the severe flooding to which Merlin engines were prone during negative G manoeuvres, making the smiting of the nimble Messerschmitt problematical during the Battle of Britain. Officially named the R.A.E. restrictor, her solution was celebrated by the RAF lads as Tilly's Orifice.
