A folding wing is a

wing configuration The wing configuration or planform of a fixed-wing aircraft (including both glider (aircraft), gliders and powered aeroplanes) is its arrangement of lifting and related surfaces. Aircraft designs are often classified by their wing configuratio ...

design feature of aircraft to save space and is typical of

carrier-based aircraft A carrier-based aircraft (also known as carrier-capable aircraft, carrier-borne aircraft, carrier aircraft or aeronaval aircraft) is a naval aircraft designed for operations from aircraft carriers. Carrier-based aircraft must be able to launch i ...

that operate from the limited deck space of

aircraft carrier An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and hangar facilities for supporting, arming, deploying and recovering carrier-based aircraft, shipborne aircraft. Typically it is the ...

s. The folding allows the aircraft to occupy less space in a confined

hangar A hangar is a building or structure designed to hold aircraft or spacecraft. Hangars are built of metal, wood, or concrete. The word ''hangar'' comes from Middle French ''hanghart'' ("enclosure near a house"), of Germanic origin, from Frankish ...

because the folded wing normally rises over the

fuselage The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...

decreasing the floor area of the aircraft. Vertical clearance is also limited in aircraft carrier hangar decks. In order to accommodate for this, some aircraft such as the

Supermarine Seafire The Supermarine Seafire is a naval version of the Supermarine Spitfire fighter adapted for operation from aircraft carriers. It was analogous in concept to the Hawker Hurricane variants#Sea Hurricanes, Hawker Sea Hurricane, a navalised aircraft ...

and

Fairey Gannet The Fairey Gannet is a carrier-borne aircraft that was designed and produced by the British aircraft manufacturer the Fairey Aviation Company. It was developed for the Royal Navy, being the first fixed-wing aircraft to combine both the search an ...

have additional hinges to fold the wingtips downward, while others such as the A-5 Vigilante and

S-3 Viking The Lockheed S-3 Viking is a four-crew, Twinjet, twin-engine turbofan-powered jet aircraft designed and produced by the American aerospace manufacturer Lockheed Corporation. Because of its characteristic sound, it was nicknamed the "War Hoover" ...

have folding tails. The

F-14 Tomcat The Grumman F-14 Tomcat is an American carrier-capable supersonic, twin-engine, tandem two-seat, twin-tail, all-weather-capable variable-sweep wing fighter aircraft. The Tomcat was developed for the United States Navy's Naval Fighter Experi ...

variable-sweep wing A variable-sweep wing, colloquially known as a "swing wing", is an airplane wing, or set of wings, that may be modified during flight, swept back and then returned to its previous straight position. Because it allows the aircraft's shape to ...

s could be "overswept" to occupy less space.

History

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 ...

, the world's first aircraft manufacturer, developed and

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling discl ...

ed folding wing mechanisms for

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

ship-borne aircraft like their Short Folder, the first patent being granted in 1913. The Folder's biplane wings were hinged so that they folded back horizontally alongside the fuselage, usually being held in place by latches projecting sideways from the rear of the

. In 1935, the

Douglas TBD Devastator The Douglas TBD Devastator is a retired American torpedo bomber of the United States Navy. Ordered in 1934, it first flew in 1935 and entered service in 1937. At that point, it was the most advanced aircraft flying for the Navy, being the firs ...

was the first aircraft to feature hydraulic folding wings, allowing the pilot to fold the wings from the cockpit without requiring other sailors to fold them manually.

Description

Comparison of F4F Wildcats with and without folded wings c1942

Since the monoplane supplanted the biplane in the late 1930s, virtually all fixed-wing aircraft designed for shipboard duty have been equipped with folding wings. Notable exceptions include the SBD Dauntless, F2A Buffalo, and A4D/A-4 Skyhawk (all USN types); the

Mitsubishi A5M The Mitsubishi A5M, formal Japanese Navy designation , experimental Navy designation Mitsubishi Navy Experimental 9-''Shi'' Carrier Fighter, company designation Mitsubishi ''Ka''-14, was a WWII-era Japanese Aircraft carrier, carrier-based fighter ...

and Yokosuka D4Y (Japanese); and the

Sea Harrier The British Aerospace Sea Harrier is a naval short take-off and vertical landing/vertical take-off and landing jet fighter, reconnaissance and attack aircraft. It is the second member of the Harrier family developed. It first entered servic ...

(British). All six are relatively compact designs. Exceptions which are currently in use, as of 2021, include the

Dassault Rafale The Dassault Rafale (, literally meaning "gust of wind", or "burst of fire" in a more military sense) is a French Twinjet, twin-engine, Canard (aeronautics), canard delta wing, Multirole combat aircraft, multirole fighter aircraft designed and ...

, the Lockheed Martin F-35B, and the McDonnell Douglas

AV-8B Harrier The McDonnell Douglas (now Boeing) AV-8B Harrier II is a single-engine Attack aircraft, ground-attack aircraft that constitutes the second generation of the Harrier jump jet, Harrier family, capable of V/STOL, vertical or short takeoff and l ...

. The Grumman-patented ''Sto-Wing'' aftwards-folding wing folding system, pioneered on the Grumman F4F-4 Wildcat, has been used since World War II on a number of Grumman-designed carrier aircraft, a version of which is still in use in the 21st century on the

Grumman E-2 Hawkeye The Northrop Grumman E-2 Hawkeye is an American all-weather, carrier-capable tactical airborne early warning (AEW) aircraft. This twin-turboprop aircraft was designed and developed during the late 1950s and early 1960s by the Grumman Aircraft ...

shipboard airborne early warning (AEW) aircraft and its

C-2 Greyhound The Grumman C-2 Greyhound is a twin-engine, high-wing cargo aircraft designed to carry supplies, mail, and passengers to and from List of United States Navy aircraft carriers, aircraft carriers of the United States Navy. Its primary mission is ...

derivative. Another Grumman naval aircraft, the

, had variable-sweep wings that could be swept between 20° and 68° in flight. For parking, the wings could be "overswept" to 75°. A folding wing has some disadvantages compared to a non-folding wing. It is heavier and has more complex connections for

electric Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwel ...

al,

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work (physics), work. The concept was originally applied solely to those materials capable of releasing chem ...

aerodynamic Aerodynamics () is the study of the motion of atmosphere of Earth, air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dynamics and its subfield of gas dynamics, and is an ...

, and structural systems. Many naval helicopters have

rotor blade On a helicopter, the main rotor or rotor system is the combination of several rotary wings (rotor blades) with a control system, that generates the aerodynamic lift force that supports the weight of the helicopter, and the thrust that countera ...

s that can be aligned over the fuselage to save space onboard ships. Folding surfaces are rare among land-based designs and are used on aircraft that are too tall or too wide to fit inside service hangars. Examples include the

Boeing B-50 Superfortress The Boeing B-50 Superfortress is a retired American strategic bomber. A post–World War II revision of the Boeing B-29 Superfortress, it was fitted with more powerful Pratt & Whitney R-4360 radial engines, stronger structure, a taller tail fin ...

and its folding tail. The

Saab 37 Viggen The Saab 37 Viggen (''The Tufted Duck'', ambiguous with ''The Thunderbolt'') is a single-seat, single-engine multirole combat aircraft designed and produced by the Swedish aircraft manufacturer Saab AB, Saab. It was the first Canard (aeronautic ...

and the

Boeing 377 The Boeing 377 Stratocruiser was a large long-range airliner developed from the C-97 Stratofreighter military transport, itself a derivative of the B-29 Superfortress. The Stratocruiser's first flight was on July 8, 1947. Design features inclu ...

Stratocruiser have foldable rear fins that make them lower for entering hangars. The

Boeing 777 The Boeing 777, commonly referred to as the Triple Seven, is an American long-range wide-body airliner developed and manufactured by Boeing Commercial Airplanes. The 777 is the world's largest twinjet and the most-built wide-body airliner. ...

(classic)

twinjet A twinjet or twin-engine jet is a jet aircraft powered by two jet engine, engines. A twinjet is able to fly well enough to land with a single working engine, making it safer than a single-engine aircraft in the event of failure of an engine. F ...

wide-body A wide-body aircraft, also known as a twin-aisle aircraft and in the largest cases as a jumbo jet, is an airliner with a fuselage wide enough to accommodate two passenger aisles with seven or more seats abreast. The typical fuselage diameter is . ...

airliner An airliner is a type of airplane for transporting passengers and air cargo. Such aircraft are most often operated by airlines. The modern and most common variant of the airliner is a long, tube shaped, and jet powered aircraft. The largest ...

was offered with folding wingtips for confined airports, though this was never ordered. The new

Boeing 777X The Boeing 777X is the latest series of the Long-haul, long-range, Wide-body aircraft, wide-body, Twinjet, twin-engine jetliners in the Boeing 777 family from Boeing Commercial Airplanes. The changes for 777X include General Electric GE9X engi ...

features a shorter and simpler folding wingtip than was planned for the earlier Boeing 777, which will provide an extra of total wingspan in flight, while allowing the airplane to fit inside the same airport gates as the 777-200LR/777-300ER. Aircraft with ventral fins under the fuselage for stability which had to be folded for takeoff and landing include the

Mikoyan-Gurevich MiG-23 The Mikoyan-Gurevich MiG-23 (; NATO reporting name: Flogger) is a variable-sweep wing, variable-geometry fighter aircraft, designed by the Mikoyan, Mikoyan-Gurevich OKB, design bureau in the Soviet Union. It is a third-generation jet fighter, ...

, the

MiG-27 The Mikoyan MiG-27 (; NATO reporting name: Flogger-D/J) is a variable-sweep ground-attack aircraft, originally built by the Mikoyan-Gurevich design bureau in the Soviet Union and later licence-produced in India by Hindustan Aeronautics as t ...

, and the Vought XF8U-3 Crusader III. An example of aircraft using folding wingtips other than stowage/hangar space such as aerodynamics and flight handling was the

North American XB-70 Valkyrie The North American Aviation XB-70 Valkyrie is a retired prototype version of the planned nuclear-armed, deep-penetration supersonic strategic bomber for the United States Air Force Strategic Air Command. Designed in the late 1950s by North A ...

. This increased both compression lift and enhanced directional stability at high speeds.

Gallery

Simple fold

File:A-6A VA-65 at NAS North Island 1966.jpeg, Grumman A-6A Intruder File:777X Roll-Out (40407369583).jpg, folding wingtip of a Boeing 777X File:Buccaneer S 2 - Elvington - BB.jpg, RAF Buccaneer S.2 File:Folding_wing_of_De_Havilland_Sea_Vixen.JPG,

De Havilland Sea Vixen The de Havilland DH.110 Sea Vixen is a British twin-engine, twin boom-tailed, two-seat, carrier-based fleet air-defence fighter flown by the Royal Navy's Fleet Air Arm from the 1950s to the early 1970s. The Sea Vixen was designed by the de Havi ...

File:Vought F-8H Crusader of VF-111 on forward elevator of USS Ticonderoga (CVA-14), in 1969.jpg, F-8H in an elevator File:F11F-1 Tiger on USS Forrestal (CVA-59) in April 1956.jpg, An F11F Tiger with downward-folded wingtips File:Super Hornet on flight deck.jpg,

F/A-18E/F Super Hornet The Boeing F/A-18E and F/A-18F Super Hornet are a series of American supersonic twinjet, twin-engine, Carrier-based aircraft, carrier-capable, Multirole combat aircraft, multirole fighter aircraft derived from the McDonnell Douglas F/A-18 Ho ...

File:hawker.sea.fury.folded.arp.jpg, Hawker Sea Fury File:sea hawk wv908 frontview arp.jpg, Hawker Sea Hawk FGA.6 Mikoyan-Gurevich MiG-29K ‘RF-92324 - 48 blue’ (36928677816).jpg,

MiG-29K The Mikoyan MiG-29K (; NATO reporting name: Fulcrum-D) is a Russian all-weather carrier-based multirole fighter aircraft developed by the Mikoyan Design Bureau. The MiG-29K was developed in the late 1980s from the MiG-29M. Mikoyan describe ...

at ARMY 2017 File:Short Folder S.64 IWM Q 090115.jpg, Short Folder S.64 being hoisted aboard the cruiser HMS ''Hermes'' (horizontal fold) MAKS-2007-Su-33-1.jpg,

Sukhoi Su-33 The Sukhoi Su-33 (-33; NATO reporting name: Flanker-D) is a Soviet/Russian all-weather carrier-based twin-engine air superiority fighter designed by Sukhoi and manufactured by Komsomolsk-on-Amur Aircraft Production Association, derived f ...

at MAKS 2007 File:North American XB-70A Valkyrie in flight (cropped).jpg,

Yakovlev Yak-38 frontview .jpg,

Yakovlev Yak-38 The Yakovlev Yak-38 (; NATO reporting name: "Forger") was Soviet Naval Aviation's only operational VTOL strike fighter aircraft in addition to being its first operational carrier-based fixed-wing aircraft. It was developed specifically for, and ...

Yakovlev Yak-141 in 2009 (2).jpg,

Yakovlev Yak-141 The Yakovlev Yak-141 (; NATO reporting name "Freestyle"), also known as the Yak-41, is a Soviet supersonic VTOL, vertical takeoff/landing (VTOL) fighter aircraft designed by Yakovlev. Intended as a replacement for the Yak-38, it was designed as ...

Aftward fold

Image:Fairey Fulmer.JPG,

Fairey Fulmar The Fairey Fulmar is a British carrier-borne reconnaissance aircraft/fighter aircraft which was developed and manufactured by aircraft company Fairey Aviation. It was named after the northern fulmar, a seabird native to the British Isles. The ...

Image:Fairey_Firefly_T.7_WM800_Ringway_17.04.53_edited-2.jpg,

Fairey Firefly The Fairey Firefly is a Second World War-era carrier-borne fighter aircraft and anti-submarine aircraft that was principally operated by the Fleet Air Arm (FAA). It was developed and built by the British aircraft manufacturer Fairey Aviation ...

File:Grumman E-1B 147223 RVAW-110 JAX 19.07.76 edited-2.jpg,

Grumman E-1 Tracer The Grumman E-1 Tracer (WF prior to 1962) was the first purpose-built airborne early warning aircraft used by the United States Navy. It was a derivative of the Grumman C-1 Trader and entered service in 1960. It was replaced by the more mode ...

with ''Sto-Wing'' system folded wings. Image:FS_CdG_Super_Hawkeye.jpg,

, which still uses a form of Grumman's ''Sto-Wing'' design. Image:F6F-3 fighters landing on USS Enterprise (CV-6).jpg, Grumman

F6F Hellcat The Grumman F6F Hellcat is an American carrier-based fighter aircraft of World War II. Designed to replace the earlier F4F Wildcat and to counter the Japanese Mitsubishi A6M Zero, it was the United States Navy's dominant fighter in the second ...

s of the

US Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

. The patented ''Sto-Wing'' system was common to Grumman fighters of World War II. MAKS2015part5-05.jpg, Kamov Ka-52K stub wings Image:Seamew folded.jpg, Short Seamew File:Supermarine Walrus Argentine Navy (4446497743).jpg, Argentinian

Supermarine Walrus The Supermarine Walrus is a British single-engine Amphibious aircraft, amphibious biplane designed by Supermarine's R. J. Mitchell. Primarily used as a maritime patrol aircraft, it was the first British Squadron (aviation), squadron-service ai ...

on a cruiser.

Double fold

Image:Seafire F XVII SX 336 wings up.jpg,

File:Fairey_Gannet_AEW3_AN1152038.jpg,

Image:Westland_Wyvern_S.4_VZ765_'181'_Stretton_25.06.55_edited-2.jpg,

Westland Wyvern The Westland Wyvern is a British single-seat carrier-based multi-role strike aircraft built by Westland Aircraft that served in the 1950s, seeing service in the 1956 Suez Crisis. Production Wyverns were powered by a turboprop engine driving l ...

Folding rotors

Ka-32S-1997.jpg, Ka-32S at MAKS 1997 Russian Navy, Kamov, Ka-52K (21444723505).jpg, Kamov Ka-52K. MAKS Airshow 2019 (2019-08-30) 432.jpg,

Kamov Ka-226 The Kamov Ka-226 (NATO reporting name: Hoodlum) is a small, twin-engine Russian utility helicopter. The Ka-226 features an interchangeable mission pod, rather than a conventional cabin, allowing the use of various accommodation or equipment co ...

US Navy 100223-N-7948R-007 A member of the flight crew folds the wings of a CH-46 Sea Knight helicopter after flight operations aboard the amphibious assault ship USS Peleliu (LHA 5).jpg, CH-46 Sea Knight File:SikorskyCH124SeaKing07A.JPG,

Sikorsky CH-124 Sea King The Sikorsky CH-124 Sea King (formerly CHSS-2) is a twin-engined anti-submarine warfare (ASW) helicopter designed for shipboard use by Canadian naval forces, based on the US Navy's SH-3 Sea King. Most CH-124s were assembled in Quebec by Unite ...

SH-60K helicopter during tail folding.jpg, Sikorsky SH-60K File:25th CAB storm preparations 140807-A-NN814-029.jpg, Sikorsky UH-60M Image:V-22 Osprey wing rotated.jpg, A

V-22 Osprey The Bell Boeing V-22 Osprey is an American multi-use, tiltrotor military transport aircraft, military transport and cargo aircraft with both vertical takeoff and landing (VTOL) and short takeoff and landing (STOL) capabilities. It is designed ...

with wings rotated parallel to fuselage

Over-swept wings

File:US Navy 040712-N-7532C-051 An F-14 Tomcat taxis to one of four steam-powered catapults during flight operations aboard USS Harry S. Truman (CVN 75).jpg, A

Grumman F-14 Tomcat The Grumman F-14 Tomcat is an American carrier-capable supersonic aircraft, supersonic, twinjet, twin-engine, Tandem#Aviation, tandem two-seat, twin-tail, all-weather-capable variable-sweep wing fighter aircraft. The Tomcat was developed for t ...

with its wings in the "oversweep" position

Folding-wing aircraft on flight decks

File:A-1J of VA-196 on USS Bon Homme Richard (CVA-31) 1964.jpg, A-1J of VA-196 on USS Bon Homme Richard Image:HMS_Victorious_(R38)_aerial_c1959.jpeg, Sea Venoms,

Scimitar A scimitar ( or ) is a single-edged sword with a convex curved blade of about 75 to 90 cm (30 to 36 inches) associated with Middle Eastern, South Asian, or North African cultures. A European term, ''scimitar'' does not refer to one specific swor ...

s, and Skyraiders on (circa 1959-1960) Image:CVE-71 launching FM-2s Samar 25Oct1944.jpg, FM-2 Wildcats on USS ''Kitkun Bay'' (1944) Soviet cruiser Admiral Isachenkov underway aerial port quarter view 1985.jpg,

Kamov Ka-25 The Kamov Ka-25 (NATO reporting name "Hormone") is a naval helicopter, developed for the Soviet Navy in the USSR from 1958. Design and development In the late 1950s there was an urgent demand for anti-submarine helicopters for deployment on n ...

on the helideck of cruiser ''Admiral Isachenkov'' File:Aircraft carrier "Minsk" in 1980.jpeg, Ka-25 Hormone and Yak-38 Forger parked on the flight deck of the Soviet aircraft carrier ''Minsk''. Storing a Russian Navy Kamov Ka-27PS (RF-34145) (4).jpg,

Ka-27PS The Kamov Ka-27 (NATO reporting name 'Helix') is a military helicopter developed for the Soviet Navy, and as of 2024 is in service in various countries including Russia, Ukraine, Vietnam, China, South Korea, and India. Variants include the Ka-2 ...

Image:USS Coral Sea (CVA-43) leaving Pearl Harbor in April 1963.jpg,

Demon A demon is a malevolent supernatural entity. Historically, belief in demons, or stories about demons, occurs in folklore, mythology, religion, occultism, and literature; these beliefs are reflected in Media (communication), media including f ...

Crusader Crusader or Crusaders may refer to: Military * Crusader, a participant in one of the Crusades * Convair NB-36H Crusader, an experimental nuclear-powered bomber * Crusader tank, a British cruiser tank of World War II * Crusaders (guerrilla), a C ...

s, Skywarriors, Trackers, Tracers, and Skyraiders on USS ''Coral Sea'' (1963) File:US Navy 031117-N-6213R-035 An S-3B Viking assigned to the.jpg, A

Lockheed S-3 Viking The Lockheed S-3 Viking is a four-crew, twin-engine turbofan-powered jet aircraft designed and produced by the American aerospace manufacturer Lockheed Corporation. Because of its characteristic sound, it was nicknamed the "War Hoover" after ...

on board USS ''John C. Stennis'' (2003) File:SH-3A Sea King of HS-6 aboard USS Kearsarge (CVS-33), circa in 1964 (NNAM.2011.113.378).jpg, SH-3A Sea King of HS-6 aboard USS Kearsarge (CVS-33), circa 1964 File:Vice_Admiral_Ajendra_Bahadur_Singh,_Flag_Officer_Commanding-in-Chief_Western_Naval_Command,_embarked_ships_of_Western_Fleet_off_the_West_Coast_of_India_from_11_to_13_October_2022,_to_review_readiness_of_the_Fleet_02.jpg,

Indian Navy The Indian Navy (IN) (ISO 15919, ISO: ) is the Navy, maritime and Amphibious warfare, amphibious branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of the Naval Staff (India), Chief ...

551-baltimora-19.jpg, SH-3D/H Sea King on

Italian aircraft carrier Giuseppe Garibaldi ''Giuseppe Garibaldi'' was an Italian aircraft carrier, the first through-deck aviation ship ever built for the Italian Navy, and the first Italian ship built to operate fixed-wing aircraft. Although she was widely recognised as a carrier first a ...

File:Cubierta de vuelo del L-61, parte de popa (34258720604).jpg, SH-3D/H Sea King on Spanish aircraft carrier ''Juan Carlos I'' File:F7U-3 VF-124 on elevator of USS Hancock (CVA-19) c1956.jpg,

Vought F7U Cutlass The Vought F7U Cutlass is a United States Navy aircraft carrier, carrier-based fighter aircraft, jet fighter and fighter-bomber designed and produced by the aircraft manufacturer Vought, Chance Vought. It was the first tailless aircraft, tailles ...

on flight deck elevator File:A3J-1s VAH-7 CVAN-65 NAN11-62.jpg,

North American A-5 Vigilante The North American A-5 Vigilante is an American carrier-based supersonic bomber designed and built by North American Aviation (NAA) for the United States Navy. Before the 1962 unification of Navy and Air Force designations, it was designated A3 ...

on flight deck. Note the folded

Vertical stabilizer A vertical stabilizer or tail fin is the static part of the vertical tail of an aircraft. The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, sta ...

File:Yak-38 fighters on Soviet carrier Minsk in 1980.jpg,

Yak-38 The Yakovlev Yak-38 (; NATO reporting name: "Forger") was Soviet Naval Aviation's only operational VTOL strike fighter aircraft in addition to being its first operational carrier-based fixed-wing aircraft. It was developed specifically for, and ...

on Soviet carrier Minsk, 1980

Notes

Bibliography

External links

{{commons category, Folding wings
The Case for the Folding Wing – Flying
Naval aviation technology Aircraft wing components