I'm fairly sure this combination of aircraft is British, but don't know the era. Moderizers please move if it doesn't fit here. In any case, it's quite unusual. I've no idea why they're connected.
View attachment 411794
The
Short Mayo Composite was a
piggy-back long-range
seaplane/
flying boat combination produced by
Short Brothers to provide a reliable long-range air transport service to
North America and, potentially, to other distant places in the
British Empire and the Commonwealth.
Short Brothers had built the
Empire flying boats which were capable of operating long range routes across the
British Empire but could only attempt the trans-Atlantic route by replacing passenger and mail-carrying space with extra fuel.
It was known that aircraft could maintain flight with a greater payload than that possible during takeoff. Major Robert H. Mayo, the Technical General Manager at
Imperial Airways, proposed mounting a small, long-range seaplane on top of a larger carrier aircraft, using the combined power of both to bring the smaller aircraft to operational height, at which time the two aircraft would separate, the carrier aircraft returning to base while the other flew on to its destination. The British
Air Ministry issued
Specification "13/33" to cover this project.
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 2,930 miles (4,720 km).
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 144 miles per hour (232 km/h).
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 6,045 miles (9,728 km) 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.