(1890-1957), aeronautical engineer Robert Hobart Mayo was born on the 25th September 1890 and was educated at the Perse School and Magdalane College, Cambridge; he showed exceptional abilities in mathematics and mechanical sciences with an inclination towards aeronautics. In 1914 at the early age of 24 he was appointed head of the experimental department at the Royal Aircraft Factory, but soon after the outbreak of war he sought action and served as a Royal Flying Corps pilot in France. Not for long was he permitted to keep his technical brilliance subdued: soon he was brought back to serve as senior commander of the Testing Squadron at Martlesham, and later as head of the Design (Aeroplane) Section, Air Ministry. In 1925 he was appointed consulting engineer to Imperial Airways, becoming their technical general manager in 1936. It was during these inter-war years that he gained world-wide recognition as the designer of the Short-Mayo composite aircraft. Its bold principle was the mounting of a very highly loaded aircraft on top of another machine of comparatively light loading, and the release of the former in such a manner that the two components separated cleanly and rapidly in the vertical plane. The upper component was a Short float seaplane, powered with four Napier Rapier engines and named Mercury; the lower was a considerably modified Short Empire-type flying-boat, Maia, with four Bristol Pegasus engines. Normal cruising speed of Mercury was about 180 m.p.h., and a duration of over 21 hours could be achieved. The combination allowed the smaller aircraft to carry a payload of 1,000 lb over a range of 3,500 miles. After a successful first separation on February 6, 1938, with Capt. J. Lankester Parker flying the lower component and Mr. H. L. Piper the upper, an Atlantic crossing was made in July of that year, Mercury reaching Montreal in 20 hr 20 min in the hands of Capt. (now A.V-M.) D. C. T. Bennett after separation from Maia (flown by Capt. A. S. Wilcockson) over Foynes. Subsequently Mercury made a number of other air-launched flights, on one of which, piloted by Bennett, it established a seaplane record—which still stands—from Scotland to South Africa. On another occasion over a ton of mail was taken non-stop to Alexandria on a routine Imperial Airways flight. In December 1938, Mayo became technical adviser to Imperial Airways. He was a former chairman of the Records, Racing, and Competitions committee of the Royal Aero Club, a past chairman of the Air League of the British Empire, a member of the National Civil Aviation Consultative Council, and a vice-president of the Federation Aeronautique Internationale. He was also a director of Airtech, Ltd. and Superflexit, Ltd. Mayo died at the age of 66 on the 26th February 1957.