Gouge flap
Encyclopedia
The Gouge flap, invented by Arthur Gouge of Short Brothers
in 1936, allowed the pilot to increase both the wing area and the chord of an aircraft's wing. This provided the benefit of a shorter take-off distance for a given load, a shorter distance to achieve a given height and a lower take-off speed. This type of flap, in spite of its use on highly successful aircraft such as the Short Sunderland
and the Short Stirling
, was superseded by other designs, notably the Fowler flap.
Excellent photographs of the fully extended flap, taken from obliquely above and below the wing, are given in the British Aeronautical Research Committee
's research paper R&M No. 1753
Among the conclusions of that report were that "flap half and fully open decreases the distance from rest to take-off by 14 per cent. and 23 per cent., and also decreases the distance from take-off to clear a 50 ft. obstacle by 21 per cent. and 23 per cent. respectively. The speed at take-off is reduced by 3 and 8 m.p.h, respectively."
fitted with the (scaled-down) wings being prepared for the Short Empire
flying-boat. The flaps on this aircraft, which was designated 'M.3', were submitted to extensive testing by the Royal Aircraft Establishment
Farnborough, their report appearing as R&M No. 1753 (see Bibliography below). Shorts used the Gouge flaps on several successful aircraft types, e.g. the Empire boats, the Short S.26
G-class 'Golden Boats', the Short Sunderland
and the Stirling
.
When Flight Magazine described the Fowler flap in 1942, the article's subtitle read "An American High-lift Device With Properties Similar to Those of the Better-known British Types", and the Gouge, Handley Page, and Fairey/Youngman flaps were all given equal mention. The Gouge flap, although widely used on Shorts aircraft, was not adopted by other manufacturers, several of which developed their own variants. The Aeronautical Research Council
's R&M no. 2622 entitled "The Aerodynamic Characteristics of Flaps" dated 1947 compared many variants but merely mentions the Gouge flap in a footnote on p.10, where it is described as being "rather like the Blackburn flap ... but with no slot between the flap and wing."
The advantage of the additional lift generated by a slot acted in the Fowler flap's success relative to the Gouge flap, as did its natural tendency to retract itself in flight.
Shorts themselves did not use the Gouge flap on their next project, the Shetland
, preferring the use of slotted flaps on this large seaplane.
Short Brothers
Short Brothers plc is a British aerospace company, usually referred to simply as Shorts, that is now based in Belfast, Northern Ireland. Founded in 1908, Shorts was the first company in the world to make production aircraft and was a manufacturer of flying boats during the 1920s, 1930s, and 1940s...
in 1936, allowed the pilot to increase both the wing area and the chord of an aircraft's wing. This provided the benefit of a shorter take-off distance for a given load, a shorter distance to achieve a given height and a lower take-off speed. This type of flap, in spite of its use on highly successful aircraft such as the Short Sunderland
Short Sunderland
The Short S.25 Sunderland was a British flying boat patrol bomber developed for the Royal Air Force by Short Brothers. It took its service name from the town and port of Sunderland in northeast England....
and the Short Stirling
Short Stirling
The Short Stirling was the first four-engined British heavy bomber of the Second World War. The Stirling was designed and built by Short Brothers to an Air Ministry specification from 1936, and entered service in 1941...
, was superseded by other designs, notably the Fowler flap.
Development
The Gouge flap was patented in 1936, British Patent no. 443,516 being awarded jointly to Short Bros. Ltd. and Arthur Gouge for "Improvements in or connected with Wings for Aircraft, (controller flaps)".The Gouge flap "consists of a sharp nosed aerofoil, which in the closed position, forms part of the wing profile . The flap tapers with the wing, i.e. the width of the flap at any point is a constant proportion of the wing chord at that point; when open the extended portion also varies with the chord. All sections through the flapped
portion of the wing are similar in shape and proportion. The flap moves on tracks, rotating conically about an imaginary axis below the wing, nearly parallel to the trailing edge. When open the flap increases the wing chord and the wing area."
Excellent photographs of the fully extended flap, taken from obliquely above and below the wing, are given in the British Aeronautical Research Committee
Advisory Committee for Aeronautics
The Advisory Committee for Aeronautics was a United Kingdom agency founded on April 30, 1909 to undertake, promote, and institutionalize aeronautical research...
's research paper R&M No. 1753
Among the conclusions of that report were that "flap half and fully open decreases the distance from rest to take-off by 14 per cent. and 23 per cent., and also decreases the distance from take-off to clear a 50 ft. obstacle by 21 per cent. and 23 per cent. respectively. The speed at take-off is reduced by 3 and 8 m.p.h, respectively."
History
Short Brothers first installed the Gouge flap on a ScionShort Scion
The Short S.16 Scion and Scion II were 1930s British two-engine, cantilever monoplanes built by Short Brothers and by Pobjoy Airmotors and Aircraft Ltd. in Rochester, Kent between 1933 and 1937...
fitted with the (scaled-down) wings being prepared for the Short Empire
Short Empire
The Short Empire was a passenger and mail carrying flying boat, of the 1930s and 1940s, that flew between Britain and British colonies in Africa, Asia and Australia...
flying-boat. The flaps on this aircraft, which was designated 'M.3', were submitted to extensive testing by the Royal Aircraft Establishment
Royal Aircraft Establishment
The Royal Aircraft Establishment , was a British research establishment, known by several different names during its history, that eventually came under the aegis of the UK Ministry of Defence , before finally losing its identity in mergers with other institutions.The first site was at Farnborough...
Farnborough, their report appearing as R&M No. 1753 (see Bibliography below). Shorts used the Gouge flaps on several successful aircraft types, e.g. the Empire boats, the Short S.26
Short S.26
|-See also:-External link:* after conversion for RAF use...
G-class 'Golden Boats', the Short Sunderland
Short Sunderland
The Short S.25 Sunderland was a British flying boat patrol bomber developed for the Royal Air Force by Short Brothers. It took its service name from the town and port of Sunderland in northeast England....
and the Stirling
Short Stirling
The Short Stirling was the first four-engined British heavy bomber of the Second World War. The Stirling was designed and built by Short Brothers to an Air Ministry specification from 1936, and entered service in 1941...
.
When Flight Magazine described the Fowler flap in 1942, the article's subtitle read "An American High-lift Device With Properties Similar to Those of the Better-known British Types", and the Gouge, Handley Page, and Fairey/Youngman flaps were all given equal mention. The Gouge flap, although widely used on Shorts aircraft, was not adopted by other manufacturers, several of which developed their own variants. The Aeronautical Research Council
Advisory Committee for Aeronautics
The Advisory Committee for Aeronautics was a United Kingdom agency founded on April 30, 1909 to undertake, promote, and institutionalize aeronautical research...
's R&M no. 2622 entitled "The Aerodynamic Characteristics of Flaps" dated 1947 compared many variants but merely mentions the Gouge flap in a footnote on p.10, where it is described as being "rather like the Blackburn flap ... but with no slot between the flap and wing."
The advantage of the additional lift generated by a slot acted in the Fowler flap's success relative to the Gouge flap, as did its natural tendency to retract itself in flight.
Shorts themselves did not use the Gouge flap on their next project, the Shetland
Short Shetland
-See also:-Bibliography:* Barnes, C.H. and James, D.N. Shorts Aircraft since 1900. London, Putnam, 1989. ISBN 0-85177-819-4.* Bowyer, Michael J.F. Aircraft for the Royal Air Force: The "Griffon" Spitfire, The Albemarle Bomber and the Shetland Flying-Boat. London: Faber & Faber Ltd., 1980. ISBN...
, preferring the use of slotted flaps on this large seaplane.
See also
- AerodynamicsAerodynamicsAerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...
- AirfoilAirfoilAn airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....
- Lift (force)Lift (force)A fluid flowing past the surface of a body exerts a surface force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the surface force parallel to the flow direction...
- Flap (aircraft)Flap (aircraft)Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...
- High-lift deviceHigh-lift deviceIn aircraft design, high-lift devices are moving surfaces or stationary components intended to increase lift during certain flight conditions. They include common devices such as flaps and slats, as well as less common features such as leading edge extensions and blown flaps.-Purpose:Aircraft...