The Short SB.6 Seamew was a British aircraft designed in 1951 by
David Keith-Lucas
David Keith-Lucas (25 March 1911 – 6 April 1997) was a British aeronautical engineer.
Early life
David Keith-Lucas was one of the sons of Alys Hubbard Lucas and Keith Lucas, who invented the first aeronautical compass. After the death of K ...
of
Shorts
Shorts are a garment worn over the human pelvis, pelvic area, circling the waist and splitting to cover the upper part of the legs, sometimes extending down to the knees but not covering the entire length of the leg. They are called "shorts" b ...
as a lightweight
anti-submarine
An anti-submarine weapon (ASW) is any one of a number of devices that are intended to act against a submarine and its crew, to destroy (sink) the vessel or reduce its capability as a weapon of war. In its simplest sense, an anti-submarine weapo ...
platform to replace the
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
Fleet Air Arm (FAA)'s
Grumman Avenger AS 4 with the Reserve branch of the service. It first flew on 23 August 1953, but, due to poor performance coupled with shifting defence doctrine, it never reached service and only 24 production aircraft had flown before the project was cancelled. It has been described as a "camel amongst race-horses".
[Winchester 2005, p. 46.]
Design and development
The Short Seamew was selected to fulfill
Admiralty
Admiralty most often refers to:
*Admiralty, Hong Kong
*Admiralty (United Kingdom), military department in command of the Royal Navy from 1707 to 1964
*The rank of admiral
*Admiralty law
Admiralty can also refer to:
Buildings
* Admiralty, Traf ...
Specification M.123D for a simple, lightweight anti-submarine aircraft capable of unassisted operation from any of the
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
's
aircraft carrier
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...
s in all but the worst of conditions, in particular escort carriers which the UK still had in considerable numbers from the Second World War. Although specifically designed for naval operations, the Seamew was also intended for land-based use by the RAF. It was to be suitable for mass production and operation by the Air Branch of the
Royal Naval Volunteer Reserve (RNVR). This specification was in response to the alarming increase in capabilities of the
Soviet
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...
submarine forces following the
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
.
![Short Seamew landing at Farnborough](https://upload.wikimedia.org/wikipedia/commons/a/a1/Short_Seamew_landing_at_Farnborough.jpg)
Three prototypes were ordered in April 1952 and the first flight (''XA209''), piloted by test pilot
Sqn. Ldr. Walter J. "Wally" Runciman, took place on 23 August 1953. This same aircraft, also piloted by Runciman, took part in the 1953
Farnborough Airshow
The Farnborough Airshow, officially the Farnborough International Airshow, is a trade exhibition for the aerospace and defence industries, where civilian and military aircraft are demonstrated to potential customers and investors. Since its fir ...
three weeks later. In 1954 both ''XA209'' and the second prototype ''XA213'' took part at Farnborough, where the following year both prototypes and two production AS Mk 1 models (''XE171'' and ''XE172'') gave a formation display.
The fourth Seamew prototype (''XE175'') was flown by Runciman for a series of sales tours in 1956 to Italy (March), Yugoslavia (April) and West Germany (May). It was this same aircraft in which Runciman was killed when it crashed during the Sydenham (Belfast) Air Display on 9 June 1956, when he attempted a loop. Rumours that the crash had been caused by a material failure were current at the time, but the accident investigation board did not confirm them.
The MR Mark 2 for use by Coastal Command was similar in every respect to the AS Mk 1 except that it was optimised for land-based use from hastily prepared airstrips. Naval equipment was deleted although manual wing folding was retained. Slightly heavier than the naval version, the MR Mk 2 had oversize low pressure tyres and could carry a higher weapons load.
Design
The pilot and observer were located in tandem cockpits located high up in the front of the deep, narrow fuselage, creating a decidedly "curious" profile.
They sat atop the
Armstrong Siddeley Mamba
The Armstrong Siddeley Mamba was a British turboprop engine produced by Armstrong Siddeley in the late 1940s and 1950s, producing around 1,500 effective horsepower (1,100 kW).
Armstrong Siddeley gas turbine engines were named after snak ...
turboprop
A turboprop is a turbine engine that drives an aircraft propeller.
A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. Fuel ...
in front and the weapons bay to the rear of them. The design had originally called for the tried and tested
Rolls-Royce Merlin
The Rolls-Royce Merlin is a British liquid-cooled V-12 piston aero engine of 27-litres (1,650 cu in) capacity. Rolls-Royce designed the engine and first ran it in 1933 as a private venture. Initially known as the PV-12, it was later ...
piston engine but the Royal Navy had made it policy to phase out piston engines, in order that supplies of highly flammable high
octane
Octane is a hydrocarbon and an alkane with the chemical formula , and the condensed structural formula . Octane has many structural isomers that differ by the amount and location of branching in the carbon chain. One of these isomers, 2,2,4-Tri ...
aviation fuel
Aviation fuels are petroleum-based fuels, or petroleum and synthetic fuel blends, used to power aircraft. They have more stringent requirements than fuels used for ground use, such as heating and road transport, and contain additives to enhanc ...
need not be carried in large quantities on ships. The turboprop engine also caused less airframe vibration so that the pilot could be sat directly over it with the absence of a piston engine ignition system which would have interfered with the radar scanner mounted below the engine housing.
[Keith-Lucas 1956, p. 81.]
For simplicity, and so that a nosewheel would not obscure the forward field of the radar scanner, a fixed tailwheel undercarriage was used. The long stroke necessary on the main undercarriage to allow for heavy deck landings while giving the radar scanner and propeller adequate clearance from the ground resulted in an alarming attitude on the ground and the cockpits mounted at a seemingly perilous height. For landing the tailwheel extended so it could land at a more level attitude.
The pilot and observer sat very far forward in order for the pilot to have a reasonable field of downward vision for takeoff and landing and so that both he and the observer had a good field of view for spotting surface vessels even when in level flight.
The large, broad-chord wings featured power-folding and
pylons for the carriage of
rocket
A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...
s,
depth charge
A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive Shock factor, hydraulic shock. Most depth ...
s,
flares and
small bombs. The large, slab-like tailplane was mounted high on the vertical stabiliser, requiring the rudder to be split into upper and lower sections. The fixed undercarriage legs could be jettisoned in the event of ditching.
[Winchester 2005, p. 47.]
The weapons bay was 14 ft long and 3 ft wide. By omitting the rotating radar scanner, it could be extended to 17 ft in order to carry longer weapons.
Handling characteristics
The handling characteristics of the Seamew were poor. The prototypes were heavily modified with fixed leading-edge slats, slots added in the trailing-edge flaps, alterations to the
aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...
s and slats added to the tailplane roots. Although something of an improvement over the initial models, the handling was never wholly satisfactory. Arthur Pearcy wrote "only Short Brothers' test pilot Wally Runciman seemed able to outwit its vicious tendencies and exploit its latent manoeuvrability to the limit."
[Pearcy 1990]
The stall speed of the Seamew was 50
knot
A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ' ...
s and it required only 50% of engine power to maintain flight. Runciman said "take off and landing are simple and straightforward", "it is, in fact, impossible to bounce the Seamew", and that its performance in crosswinds was "outstanding".
Operational history
An order was placed in February 1955 for 60 aircraft (split evenly between the
FAA
The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic m ...
and
RAF
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and ...
), with Seamew ''XA213'' successfully completing carrier trials on
HMS ''Bulwark'' in July and December 1955. Naval service flight trials with two Seamews were carried out with
700 Naval Air Squadron
700 Naval Air Squadron (700 NAS) is an experimental test squadron in the Royal Navy’s Fleet Air Arm.
History
700 NAS was originally formed on 21 January 1940 at RNAS Hatston (HMS ''Sparrowhawk'') in Orkney in a plan to centralise the operations ...
in November 1956, which included catapult trials and around 200 takeoffs and landings on
HMS ''Warrior''.
The RAF lost interest after four Mk 2s were built
with three of them converted to AS1 standard; the fourth (''XE175'') was flown by S/L W. "Wally" J. Runciman for a series of sales tours in 1956 to Italy (March), Yugoslavia (April) and West Germany (May).
Meanwhile, the FAA decided that the RNVR Avengers would be replaced by Seamews, but only four had been taken on charge by the time the RNVR squadrons were disbanded in March 1957 in keeping with the
1957 Defence White Paper
The 1957 White Paper on Defence (Cmnd. 124) was a British white paper issued in March 1957 setting forth the perceived future of the British military. It had profound effects on all aspects of the defence industry but probably the most affected wa ...
, before any Seamews were allocated to them. Seven aircraft eventually delivered to the FAA were scrapped at
RNAS Lossiemouth
Lossiemouth ( gd, Inbhir Losaidh) is a town in Moray, Scotland. Originally the port belonging to Elgin, it became an important fishing town. Although there has been over 1,000 years of settlement in the area, the present day town was formed over ...
, and the other 11, complete and awaiting delivery, were scrapped at Sydenham. The last surviving Seamew, ''XE180'' which had been purchased by Shorts on 31 August 1959 for ground instruction at its Apprentice Training School, was scrapped in 1967.
"XE180."
''belfastforum.co.uk'', 2010. Retrieved: 12 December 2010.
The Rolls-Royce Heritage Trust
The Rolls-Royce Heritage Trust is an organisation that was founded in 1981 to preserve the history of Rolls-Royce Limited, Rolls-Royce Holdings and all merged or acquired companies. Five volunteer led branches exist, three in England, one in Sco ...
has preserved a Seamew engine, which is found at its Coventry branch.
Variants
;SB.6 Seamew
:Three prototype anti-submarine aircraft, one completed as a structural test rig.
;SB.6 Seamew AS.1
:Production anti-submarine aircraft for the Royal Navy, 60 aircraft ordered later amended to 30 but only 24 completed.
;SC.2 Seamew MR.2
:Production aircraft for the Royal Air Force Coastal Command, larger wheels with low-pressure tyres, manual wing-folding and no deck handling gear, 30 aircraft ordered but only 4-built that were converted or completed to AS.1 standard.
Operators
;
* Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
* Royal Naval Reserve
The Royal Naval Reserve (RNR) is one of the two volunteer reserve forces of the Royal Navy in the United Kingdom. Together with the Royal Marines Reserve, they form the Maritime Reserve. The present RNR was formed by merging the original Ro ...
Specifications (Seamew AS 1)
See also
Notes
Citations
Bibliography
* Barnes, C.H. with revisions by Derek N. James. ''Shorts Aircraft since 1900''(revised). London: Putnam, 1989. .
* Green, William and Gerald Pollinger. ''The Observer's Book of Aircraft''. London: Frederick Warne & Co. Ltd., 1956.
* Keith-Lucas, David
"Short Seamew."
''Flight,'' 20 January 1956, pp. 81–86.
* Pearcy, Arthur. "Short Seamew". ''Aviation News 6'', 19 July 1990.
* Runciman, Squadron Leader W.J. ''Pilot's Flying Log Book''. "Squadron Leader W.J. Runciman, A.F.C., D.F.M." Original held by his family, a copy held by P. Sortehaug, 4, William St., Dunedin, NZ.
* "The Seamew Calls a Halt to the Rising Cost of Air Power." ''Shorts Quarterly Review'', Vol. 2, No. 3, Autumn 1953.
* ''The Short Seamew Light Anti-submarine Aircraft'' (promotional brochure). Belfast: Short Brothers and Harland Limited, c. 1953.
* Williams, Ray. ''Fly Navy: Aircraft of the Fleet Air Arm since 1945''. London: Airlife Publishing, 1989. .
*
* Winchester, Jim, ed. "Short Seamew". ''The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters''. London: Amber Books Ltd., 2005. .
External links
a 1954 ''Flight'' advertisement for the Seamew
{{Short Brothers aircraft
Short Brothers aircraft
1950s British anti-submarine aircraft
Single-engined tractor aircraft
Single-engined turboprop aircraft
Carrier-based aircraft
Mid-wing aircraft
Aircraft first flown in 1953