upper component was in fore-aft balance so trim could be adjusted prior to release. The pilots could then release their respective locks. At this point the two aircraft remained held together by a third lock which released automatically at . The design was such that at separation Maia would tend to drop while Mercury would climb. Operations The first successful in-flight separation was carried out from the Shorts works at Borstal, near Rochester, Medway, on 6 February 1938, Maia piloted by Parker and Mercury by Harold Piper. Following further successful tests, the first transatlantic flight was made on 21 July 1938 from Foynes, on the Shannon Estuary, west coast of Ireland, to Boucherville, near Montreal, Quebec, Canada, a flight of . Maia, flown by Captain A.S. Wilcockson, took off from Southampton carrying Mercury piloted by Captain Don Bennett. As well as Mercury, the launch aircraft Maia was also carrying 10 passengers and luggage. Mercury separated from her carrier at 8 pm to continue what was to become the first commercial non-stop East-to-West transatlantic flight by a heavier-than-air machine. This initial journey took 20 hrs 21 min at an average ground speed of . The Maia-Mercury composite continued in use with Imperial Airways, including Mercury flying to Alexandria, Egypt, in December 1938. After modifications to extend Mercury'''s range, it established a record flight for a seaplane of from Dundee in Scotland to Alexander Bay, in South Africa between 6 and 8 October 1938. Only one example of the Short-Mayo composite was built, the S.21 Maia with the registration G-ADHK and the S.20 Mercury G-ADHJ. The development of a more powerful and longer-range Empire boat (the Short S.26), the increase in allowable all-up weights with the standard "C-Class", the further development of in-flight refuelling and the outbreak of the Second World War combined to render the approach obsolete. Maia was destroyed in Poole Harbour by German bombers on 11 May 1941. Mercury was flown to Felixstowe for use by 320 (Netherlands) Squadron RAF a unit of the Royal Air Force formed from the personnel of the Royal Netherlands Naval Air Service. This squadron was based at the time at RAF Pembroke Dock. When this squadron was re-equipped with Lockheed Hudsons, Mercury was returned to Shorts at Rochester on 9 August 1941 and broken up so that its aluminium could be recycled for use in the war effort. Legacy On the Tay Embankment