Short Mayo Composite
The Short Mayo Composite was a combination of a four-engined flying boat and a four-engined floatplane on his back. It should be used for transatlantic air mail transport.
It was in the early 1930s, no British aircraft, which would have made a safe and reliable air transportation across the Atlantic. But you knew that an aircraft with more load than it can start flying. So the aircraft manufacturer Short Brothers was commissioned to build planes corresponding to two. To their operation founded in 1935, the technical director of the Imperial Airways, Major RH Mayo, Mayo Composite Aircraft Company Ltd..
As a carrier aircraft served the Short S. 21 Maia, a flying boat with four 920 -hp Bristol Pegasus XC- nine-cylinder radial engines, it corresponded to the interpretation a short p.23 Empire. The first flight of S. 21 was held on 27 July 1937. Except for the piggyback testing it also served as a navigation trainer.
The upper half of the combination formed the Short p. 20 Mercury. She was a shoulder wing float plane with four engines, initially Napier Rapier V, later Rapier VI H engines with 374 hp. On August 26, 1937, she first came in the air that Mercury reached a cruising speed of 290 km / h The launch mass of 7030 kg could be increased by the mother aircraft to 2268 kg.
The first piggyback launch took place on January 21, 1938 and February 6, the first successful separation could be performed. After a series of tests and trials of the first commercial flight took place on 21 July 1938. This could be carried after the separation on the Irish coast, 272 kg of cargo and mail to Montreal in Canada. The 4600 km long distance could be covered in 20 hours and 30 minutes; which corresponded to an average speed of 285 km / h On the return flight, the Azores were achieved after 7.5 hours.
On October 6, 1938, Mercury was able to land in 42 hours on the Orange River in South Africa after the separation over Dundee, Scotland. The aircraft was fully refueled without cargo and should actually fly to Cape Town, but the fuel gauge was not enough, however, the non-stop flight over 9726 km meant a new world record. The last piggyback flights took place on the route Southampton - Alexandria in November 1938 and January 1939. The threat of war prevented then the other common use.
The " Maia " was then converted to passenger transport and used in air traffic until it was destroyed in an air raid on 11 May 1942 at the port of Poole. When war broke out, the Royal Air Force (No. 320 Squadron RAF) confiscated the "Mercury" and used them for training. But in August 1941 she came back to short and was scrapped.