 Test flights revealed that the prototype was very manoeuvrable and "a delight to fly".After being badly damaged in a landing accident in July 1939, it was re-engined with 900 hp Taurus T-S(a)-IIIs in 1940, which reduced its performance.A second prototype ("L8002") with 880 hp Rolls-Royce Peregrine I liquid-cooled, inline engines flew on 22 February 1940; it proved capable of at .