 These different engines were housed under a variety of cowlings, mostly short chord Townend rings but also wider chord cowlings with and without blisters for cylinder heads.The prototype, "G-ACMT", first flew on 26 June 1934 and in July 1934 appeared in public for the first time at an exhibition by the Society of British Aircraft Constructors (SBAC) at Hendon.Small-scale production then began at the Portsmouth factory.