Short Mayo Composite

Short Brothers had built the Empire flying boats which were capable of operating long range routes in 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 take-off. Major Robert 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 Short-Mayo composite project, co-designed by Mayo and Shorts chief designer Arthur Gouge, comprised the Short S.21 Maia, (G-ADHK) which was a variant of the Short "C-Class" Empire flying-boat, fitted with a trestle or pylon on the top of the fuselage to support the Short S.20 Mercury(G-ADHJ).{{efn|Named after Maia, the Greek goddess and mother of Hermes, messenger of the Gods, while Hermes was known to the Romans as Mercury.{{sfn|Barnes|James|1989|p=560}}}}"[http://www.flightglobal.com/pdfarchive/view/1962/1962%20-%202457.html World News: Sir Arthur Gouge]". Flight International, 25 October 1962, page 660Flight 19 August 1937 p180

Although generally similar to the Empire boat, Maia differed considerably in detail: the hull sides were flared and had "tumblehome" rather than being vertical as on the Empire to increase the planing surface (necessary for the higher take-off weights); larger control surfaces; an increase in total wing area from {{cvt|1500|sqft}} to {{cvt|1750|sqft}}; the engines were mounted further from the wing root to clear Mercury's floats and the rear fuselage was swept up to raise the tailplane relative to the wing. Like the Empire boats, Maia could be equipped to carry 18 passengers.{{sfn|Barnes|James|1989|p=560}} Maia first flew (without Mercury) on 27 July 1937, piloted by Shorts' Chief Test Pilot, John Lankester Parker.J Lankester Parker OBE FRAeS Hon MSLAE started as a test pilot at Shorts in 1916, was Chief Test Pilot 1918–1945 and from 1943 a Director of Short Brothers and Harland, Belfast

The upper component, Mercury, was a twin-float, four-engine seaplane crewed by a single pilot and a navigator, who sat in tandem in an enclosed cockpit. It could carry {{cvt|1000|lb}} of mail and {{cvt|1200|impgal}} of fuel. Flight controls, except for elevator and rudder trim tabs, were locked in neutral until separation. Mercury's first flight, also piloted by Parker, was on 5 September 1937.{{sfn|Jackson|1974|p=302}}

The mechanism that held the two aircraft together allowed for a small degree of movement. Lights indicated when the 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 {{cvt|3000|lbf}}. The design was such that at separation Maia would tend to drop while Mercury would climb.Flight 17 February 1938

File:Maia and Mercury, August 1938 (Our Generation, 1938).jpg

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,[http://www.borstal.org.uk/history/shorts.shtml Shorts History], Borstal; contains an eye-witness account of the first in-flight separation. {{webarchive |url = https://web.archive.org/web/20081118194510/http://www.borstal.org.uk/history/shorts.shtml |date=18 November 2008 }} near Montreal, Quebec, Canada, a flight of {{convert|2930|mi|km}}. Maia, flown by Captain A.S. Wilcockson, took off from Southampton carrying Mercury piloted by Captain Don Bennett.{{Efn|Captain Bennett was later the first commander of the RAF Pathfinder Force in WWII and became an Air Vice Marshal}} As well as Mercury, the launch aircraft Maia was also carrying 10 passengers and luggage."Mercury makes good" p. 80 Mercury separated from her carrier at 8 pm to continue what was to become the first commercial{{efn|The British flying boats Caledonia and Cambria had already made several non-stop survey flights of the Atlantic route.}} non-stop East-to-West transatlantic flight by a heavier-than-air machine. This initial journey took 20 h 21 min at an average ground speed of {{convert |144|mph}}.[http://www.flightglobal.com/pdfarchive/view/1938/1938%20-%202137.html "Mercury makes good"] Flight 28 July 1938. pp. 79-80

File:Maia and Mercury.jpg

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 {{convert|6045|mi|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.{{sfn|Cassidy|2004|p=58}} 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.{{sfn|Barnes|James|1989|p=311}}

On the Tay Embankment close to the {{RRS|Discovery}} there is a bronze plaque attached to the seawall."Mercury Seaplane's long-distance flight record; Scottish Visitor"{{cite web|title=Scottish Visitor - Mercury Seaplane|url=https://www.scottishvisitor.co.uk/mercury-seaplane/|access-date=18 November 2017}}{{Dead link|date=July 2018 |bot=InternetArchiveBot |fix-attempted=yes }} This commemorates the world record long-distance seaplane flight, at a location where the estuary and hills behind the take-off waters are seen. The plaque shows in raised relief the two aircraft still joined but reaching the altitude at which they would have separated. The plaque also contains wording including: - ″Commemoration of the 1938 flight of Captain Bennett from the Tay Estuary to South West Africa... The world record long-distance flight by a seaplane was achieved by the aircraft "Mercury", the upper component of the Short Mayo... The two experimental planes ...were built by Short Brothers for Imperial Airways and designed to carry mail long distances without refueling... This tribute to the epic flight by Captain D.C.T. Bennett and First Officer Ian Harvey was unveiled by Captain Bennett's wife Mrs Ly Bennett and Lord Provost Mervyn Rollo on 4 October 1997.″

The concept also had an unusual legacy, since in 1976 NASA needed to transport the Space Shuttle between the Kennedy Space Center and Edwards Air Force Base between each mission, and to get the craft airborne for gliding tests. Jim McLaughlin, Chief Weights Engineer for Boeing 747 program, who was assisting NASA with the SCA Program, was previously the Chief Weights Engineer for Short Brothers and had been involved in the development of the Mayo Composite design at Shorts, and reminded a NASA engineer of the concept which enabled NASA to modify a second-hand Boeing 747 as the carrier aircraft accordingly.{{cite book|last1=White|first1=Rowland|title=Into the Black|date=2018|publisher=Bantam Press|location=London|isbn=978-0-593-06436-8|page=129}}

{{UK}}

• Imperial Airways
• Royal Air Force
• No. 320 Squadron RAF

{{Aircraft specs

|ref={{sfn|Barnes|James|1989|p=312}}

|prime units?=imp

|genhide=

|crew=2 (pilot and navigator/radio operator)

|capacity={{convert|1000|lb|kg|-1|abbr=on}} of mailBarnes 1967, p. 305.

|length m=

|length ft=51

|length in=0

|span m=

|span ft=73

|span in=0

|height m=

|height ft=20

|height in=3

|height note={{sfn|Angelucci|1984|p=226}}

|wing area sqm=

|wing area sqft=611

|empty weight kg=

|empty weight lb=10163

|gross weight kg=

|gross weight lb=15500

|gross weight note= (solo - i.e. non-composite take-off)

|more general = *Composite launch weight:

• {{convert|20800|lb|kg|-1|abbr=on}} (Normal composite launch weight)
• {{convert|26800|lb|kg|-1|abbr=on}} (Record composite launch weight - Cape flight)

|fuel capacity=

|eng1 number=4

|eng1 name=Napier Rapier VI

|eng1 type=16-cylinder "H-block" piston engines

|eng1 kw=

|eng1 hp=365

|eng1 shp=

|prop blade number=

|prop name=

|prop dia m=

|prop dia ft=

|prop dia in=

|perfhide=

|max speed kmh=

|max speed mph=212

|max speed kts=

|max speed mach=

|cruise speed kmh=

|cruise speed mph=195

|cruise speed kts=

|range km=

|range miles=3900

|range nmi=

|range note=

• Extended range: {{convert|6100|mi|nmi km|-1|abbr=on}} (Cape flight)

|ceiling m=

|ceiling ft=

|climb rate ms=

|climb rate ftmin=

|wing loading lb/sqft=33.6

|wing loading note=

|more performance=

|avionics=

}}

{{Aircraft specs

|ref={{sfn|Barnes|James|1989|p=312}}

|prime units?=imp

|genhide=

|crew=3

|capacity=18 passengers

|length m=

|length ft=84

|length in=11

|span m=

|span ft=114

|span in=0

|height m=

|height ft=32

|height in=7+1/2

|height note={{sfn|Angelucci|1984|p=226}}

|wing area sqm=

|wing area sqft=1750

|empty weight kg=

|empty weight lb=24745

|gross weight kg=

|gross weight lb=27700

|gross weight note= (limit on weight of Maia for composite launching)

|max takeoff weight lb=38000

|fuel capacity=

|eng1 number=4

|eng1 name=Bristol Pegasus XC

|eng1 type=nine-cylinder radial engines

|eng1 kw=

|eng1 hp=919

|prop blade number=

|prop name=

|prop dia m=

|prop dia ft=

|prop dia in=

|perfhide=

|max speed kmh=

|max speed mph=200

|max speed kts=

|max speed mach=

|cruise speed kmh=

|cruise speed mph=

|cruise speed kts=

|range km=

|range miles=850

|range nmi=

|ceiling m=

|ceiling ft=20000

|climb rate ms=

|climb rate ftmin=

|more performance=

|avionics=

}}

{{Aircontent

|related=

• Short Empire
• Short S.26

|similar aircraft=

• Felixstowe Porte Baby

|lists=

• List of flying boats and floatplanes
• List of aircraft of the Royal Air Force

}}

;Notes

{{notelist}}

;Citations

{{Reflist|refs=

{{sfn| Jackson|1974|p=302}}

}}

• {{cite book |title=World Encyclopedia of Civil Aircraft |last=Angelucci |first=Enzo |year=1984 |publisher=Willow Books |location=London |isbn=0-00-218148-7}}
• {{cite book |last1=Barnes |first1=C.H. |last2=James |first2=D.N. |title=Shorts Aircraft since 1900 |year=1989 |publisher=Putnam |location=London |isbn = 0-85177-819-4}}
• {{cite book |last=Cassidy |first=Brian |title=Flying Empires - Short 'C' class Empire flying boats |publisher=Queens Parade Press |year=2004 |isbn=0-9529298-2-1}}
• {{cite book |last=Jackson |first= A.J. |title=British Civil Aircraft since 1919 |volume=III |year=1974 |publisher=Putnam |location=London |isbn=0-370-10014-X}}
• [http://www.flightglobal.com/pdfarchive/view/1935/1935%20-2-%200522.html Composite Aircraft Flight 1935]
• [http://www.flightglobal.com/pdfarchive/view/1937/1937%20-%202284.html The Great Experiment Flight 1937]
• {{cite journal

| title = Short Mayo - The Composite Aircraft Described in Detail

| journal =Flight

| volume = XXXIII

| issue =1521

| pages = (Supplement at p.159.)

| publisher = Reed Business Information Ltd.

| date = 17 February 1938

| url =http://www.flightglobal.com/pdfarchive/view/1938/1938%20-%200439.html

| format =PDF

| access-date = 7 July 2011}}

{{commons category|Short Mayo Composite}}

{{external media|float=right|video1= British Movietone News [https://www.youtube.com/watch?v=bYtazEBQ1K8&NR=1 film footage]}}

{{Externalimage|float=right|image1= [http://www.flightglobal.com/FlightPDFArchive/1938/1938%20-%200599.pdf Sequence of photos taken during first public separation (at Flight PDF Archive)]}}

• [https://web.archive.org/web/20070930102112/http://www.time.com/time/magazine/article/0,9171,787965,00.html 1935 article describing the proposed Short-Mayo Composite]
• [https://books.google.com/books?id=wt8DAAAAMBAJ&dq=Popular+Science+1935+plane+%22Popular+Mechanics%22&pg=PA562 "Flying Boat Launches Sea Mail Plane in Air"] Popular Mechanics, April 1935, article with drawing explaining concept of purposed Short Mayo Composition.
• [http://aerostories.free.fr/appareils/compopara/page14.html Aero Stories]
• [https://web.archive.org/web/20100826053011/http://www.time.com/time/magazine/article/0,9171,848848,00.html Contemporary article in Time magazine, 14 February 1938]
• [https://web.archive.org/web/20070413042855/http://iwn.iwai.ie/v28i4/flying_boats_foynes.PDF Irish Inland Waterway News, Winter 2001]
• [https://web.archive.org/web/20061018224014/http://www.imperial-airways.com/History_page_3.html Imperial Airways history]
• [https://web.archive.org/web/20061208155527/http://www.historyofaircargo.com/i-The-Short-Mayo-Composite-Mercury-and-Mai.html Image of the Maia/Mercury at www.historyofaircargo.com]
• [https://web.archive.org/web/20110927065546/http://www.gapan.org/about-the-guild/general-information/75-years-of-history/ Download link for "The Guild of Aircraft Pilots and Navigators of London 1929 - 2004"]
• {{citation |chapter-url=http://www.wondersofworldaviation.com/short-mayo-aircraft.html |chapter=The Short-Mayo aircraft |title=Wonders of World Aviation |year=1938 |pages=25–29 |editor-first=Clarence |editor-last=Winchester }}

{{Short Brothers aircraft}}

Category:Articles containing video clips

Category:1930s British airliners

Category:Composite aircraft

Category:Eight-engined tractor aircraft

Category:Parasite aircraft

Category:Flying boats

Mayo Composite

Category:Aircraft first flown in 1937

Category:Floatplanes