The Airspeed AS.39 Fleet Shadower was a British long-range patrol aircraft design that did not go beyond the
prototype
A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototyp ...
stage. A similar aircraft, the
General Aircraft Fleet Shadower
The General Aircraft G.A.L.38 Fleet Shadower was a British long-range patrol aircraft design of the immediate pre-Second World War period. The Fleet Shadower was a highly specialized aircraft intended to follow enemy naval task forces over long t ...
, was also built to the extent of prototypes. While the concept of a fleet shadower had some promise, the resulting designs were soon overtaken by wartime developments in airborne radar.
Design and development
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 ...
envisaged a need (Operational Requirement OR.52) for an aircraft that could shadow enemy fleets at night and the resulting
Specification S.23/37 called for a slow-flying low-noise aircraft with a long range, capable of operating from an
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
flight deck
The flight deck of an aircraft carrier is the surface from which its aircraft take off and land, essentially a miniature airfield at sea. On smaller naval ships which do not have aviation as a primary mission, the landing area for helicopters ...
. The specified performance was to be a speed of at for not less than six hours.
[Jarrett ''Aeroplane Monthly'' April 1992, pp. 16–19.]
Five companies showed interest:
Percival
Percival (, also spelled Perceval, Parzival), alternatively called Peredur (), was one of King Arthur's legendary Knights of the Round Table. First mentioned by the French author Chrétien de Troyes in the tale ''Perceval, the Story of the G ...
,
Short Brothers
Short Brothers plc, usually referred to as Shorts or Short, is an aerospace company based in Belfast, Northern Ireland. Shorts was founded in 1908 in London, and was the first company in the world to make production aeroplanes. It was particu ...
,
Fairey Aviation
The Fairey Aviation Company Limited was a British aircraft manufacturer of the first half of the 20th century based in Hayes in Middlesex and Heaton Chapel and RAF Ringway in Cheshire. Notable for the design of a number of important military a ...
,
General Aircraft Ltd
General Aircraft Limited was a British aircraft manufacturer from its formation in 1931 to amalgamation with Blackburn Aircraft in 1949 to become Blackburn and General. Its main products were military gliders and light transport aircraft.
His ...
and
Airspeed
In aviation, airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are:
* Indicated airspeed ("IAS"), what is read on an airspeed gauge connected to a Pitot-static system;
* Calibrated a ...
.
General Aircraft submitted the
G.A.L.38, of very similar general design to the AS.39.
General Aircraft and Airspeed were selected to build two prototypes each and Airspeed received a contract on 10 August 1938.
The AS.39 was a high-wing, semi-
cantilever
A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a canti ...
, strut-braced (on the outer panels)
monoplane
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes.
A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...
with wooden wings and
tail unit and an all-metal
monocoque
Monocoque ( ), also called structural skin, is a structural system in which loads are supported by an object's external skin, in a manner similar to an egg shell. The word ''monocoque'' is a French term for "single shell".
First used for boats, ...
fuselage
The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...
. It had a fixed, divided type
landing gear and tailwheel. The observation aircraft had a crew of three: pilot, observer and radio operator. The AS.39 had a unique crew configuration with the observer accommodated in the nose with clear-vision windows on three sides and the pilot's compartment raised to allow passage to the radio operator's compartment. Four small
Pobjoy Niagara V
The Pobjoy Niagara is a British seven-cylinder, air-cooled, radial, aero-engine first produced in 1934. The design ran at higher speeds than conventional engines, and used reduction gearing to lower the speed of the propeller. This led to a noti ...
seven-cylinder
air-cooled radial engines were mounted on the wings. This maximized propwash over the wing giving extra lift at low speed. The wings could be folded for storage when used on an aircraft carrier.
[Bridgman, Leonard. ''Jane's Fighting Aircraft of World War II''. New York: Crescent Books, 1988. .]
Operational history
Of two prototypes started, only one was completed, flying on 17 October 1940, the first flight was delayed due to problems with the Niagara V engines which had a vibration problem. The prototype had stability problems and poor
stall handling not helped by the under-powered engines. Airspeed were asked to respond to a proposal to re-engine the aircraft with two
Armstrong Whitworth Cheetah XI
The Armstrong Siddeley Cheetah is a seven-cylinder British air-cooled aircraft radial engine of 834 cu in (13.65 L) capacity introduced in 1935 and produced until 1948. Early variants of the Cheetah were initially known as the Lynx Major.Lums ...
radial engines and add rear-facing machine guns. Only a preliminary proposal had been made and the second aircraft was not complete when on 17 February 1941 the Navy cancelled the fleet shadower program along with the AS.39,
the company were requested to scrap both aircraft. The competing G.A.L.38 flew for a few months before it was cancelled and scrapped in March 1942. The requirement for such aircraft had been made obsolete due to the introduction of
radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...
on long-range patrol aircraft such as the
Liberator I
Consolidated Liberator I was the service name of the first Consolidated B-24 Liberator four-engined bombers to see use with the Royal Air Force (RAF).
A small number of B-24s were purchased for the RAF but assessment showed that they were not s ...
.
Specifications (AS.39)
See also
References
;Notes
;Bibliography
"Airspeed Types."''Flight,'' 1951
* Bridgman, Leonard, ed. ''Jane’s All The World’s Aircraft 1945–1946''. London: Samson Low, Marston & Company, Ltd, 1946.
* Butler, Phil. "The Night Shawdowers." ''Air-Britain Aeromilitaria'' Vol. 32, Issue 125, Spring 2006, pp. 19–22. ISSB 0262-8791.
''Fleet Air Arm archive''. Retrieved: 2 February 2007.
* Jarrett, Phil. "Nothing ventured...", Part 24. ''Aeroplane Monthly'', April 1992, Vol 20 No 4. London: IPC. ISSN 0143-7240. pp. 16–19.
* Jarrett, Phil. "Nothing ventured... General Aircraft GAL 38 Night Shadower". ''Aeroplane Monthly'', May 1992, Vol 20 No 5. London: IPC. ISSN 0143-7240. pp. 18–23.
* Jarrett, Phil. "Nothing ventured... Airspeed AS.39 Night Shadower". ''Aeroplane Monthly'', June 1992, Vol 20 No 6. London: IPC. ISSN 0143-7240. pp. 52–57.
* Winchester, Jim, ed. "General Aircraft Fleet Shadower (1940)". ''The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters''. London: Amber Books Ltd., 2005. .
External links
{{Airspeed aircraft
Fleet Shadower
1940s British patrol aircraft
Cancelled military aircraft projects of the United Kingdom
Carrier-based aircraft
Four-engined tractor aircraft
High-wing aircraft
Aircraft first flown in 1940
Four-engined piston aircraft