A bubble canopy is an aircraft canopy constructed without bracing, for the purpose of providing a wider unobstructed field of view to the pilot, often providing 360° all-round visibility. The designs of bubble canopies can vary drastically; some, such as on later versions of the

F4U Corsair The Vought F4U Corsair is an American fighter aircraft that saw service primarily in World War II and the Korean War. Designed and initially manufactured by Chance Vought, the Corsair was soon in great demand; additional production contracts ...

, are built into the upper rear fuselage, while others, like the canopy of the

P-51D Mustang Over twenty variants of the North American P-51 Mustang fighter were produced from 1940, when it first flew, to after World War II, some of which were employed also in the Korean War and in several other conflicts. Allison-engined Mustangs NA- ...

and most modern combat aircraft, are built flush with the fuselage, providing unobstructed rear visibility. Although experimented with as early as the

First World War World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

, the bubble canopy was brought into widespread use during the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, being used by a number of American,

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

, and

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

ese aircraft, commonly fighters. During the

postwar A post-war or postwar period is the interval immediately following the end of a war. The term usually refers to a varying period of time after World War II, which ended in 1945. A post-war period can become an interwar period or interbellum, ...

era, the bubble canopy became a common feature of jet-powered fighter aircraft. Outside of combat aircraft, such canopies have also been adopted by several helicopters and

general aviation General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations except for commercial air transport or aerial work, which is defined as specialized aviation services for other ...

aircraft, often for roles that benefit from a high level of exterior visibility, such as

aerial reconnaissance Aerial reconnaissance is reconnaissance for a military or Strategy, strategic purpose that is conducted using reconnaissance aircraft. The role of reconnaissance can fulfil a variety of requirements including Artillery observer, artillery spott ...

History

The bubble canopy had been in use well before

; a number of experimental bubble canopy designs has been tested during the

. British aircraft designers developed the Malcolm hood, a bulged canopy, that was first adopted on the

Supermarine Spitfire The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and other Allies of World War II, Allied countries before, during, and after World War II. It was the only British fighter produced conti ...

and subsequently other aircraft. The British Miles M.20 was amongst the first aircraft designs to feature a true one-piece sliding bubble canopy. Although that aircraft never went into production, the concept of the bubble canopy was later used on other British aircraft, such as the

Hawker Typhoon The Hawker Typhoon was a British single-seat fighter-bomber, produced by Hawker Aircraft. It was intended to be a medium-high altitude interceptor aircraft, interceptor, as a replacement for the Hawker Hurricane, but several design problems we ...

and Tempest. Subsequently, Malcolm hood-style canopies were fitted to the

North American P-51 Mustang The North American Aviation P-51 Mustang is an American long-range, single-seat fighter and fighter-bomber used during World War II and the Korean War, among other conflicts. The Mustang was designed in 1940 by a team headed by James H. Kin ...

and

Republic P-47 Thunderbolt The Republic P-47 Thunderbolt is a World War II-era fighter aircraft produced by the American company Republic Aviation from 1941 through 1945. It was a successful high-altitude fighter, and it also served as the foremost American fighter-bombe ...

, amongst other aircraft. A well-framed version of an all-around vision canopy was also used on the

Imperial Japanese Navy Air Service The (IJNAS) was the air arm of the Imperial Japanese Navy (IJN). The organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War. The Japanese military acquired its first aircraft in ...

Mitsubishi A6M ''Zero'' Japanese naval fighter. Different designs, with much less framing than the "Zero" hood, were used on the

Imperial Japanese Army Air Service The Imperial Japanese Army Air Service (IJAAS) or Imperial Japanese Army Air Force (IJAAF; ) was the Military aviation, aviation force of the Imperial Japanese Army (IJA). Its primary mission was to provide tactical close air support for ground ...

Nakajima Ki-43 ''Oscar'' and

Nakajima Ki-84 The is a single-seat fighter flown by the Imperial Japanese Army Air Service in the last two years of World War II. The Allied reporting name was "Frank"; the Japanese Army designation was . The Ki-84 is generally considered the best Japanes ...

''Frank'' land-based fighter aircraft. The

Bell 47 The Bell 47 is a single-rotor single-engine light helicopter manufactured by Bell Helicopter. It was based on the third Bell 30 prototype, which was the company's first helicopter designed by Arthur M. Young. The 47 became the first heli ...

helicopter was the first production helicopter certified for civilian use in the United States, and in its Model 47D version, pioneered the "soap bubble"-style canopy for light helicopters – as named by its designer, Arthur M. Young – that it and the 47G model were to become famous for. Following after the Bell 47, various other rotorcraft have used bubble canopies, including the

Robinson R44 The Robinson R44 is a four-seat light helicopter produced by Robinson Helicopter Company since 1992. Derived from the company's two-seat Robinson R22, the R44 features hydraulically assisted flight controls and a larger engine. It was first ...

, Schweizer S333, and the

Mil Mi-24 The Mil Mi-24 (; NATO reporting name: Hind) is a large helicopter gunship, attack helicopter and low-capacity transport helicopter, troop transport with room for eight passengers. It is produced by Mil Moscow Helicopter Plant and was introduced ...

, the later versions of the latter possessing a distinctive tandem cockpit with a "double bubble" canopy that replaced its original angular greenhouse-style cockpit arrangement. Numerous jet-powered fighter aircraft of the

era adopted bubble canopies. One of the more prominent external differences between the ground-attack orientated

Hawker Siddeley Harrier The Hawker Siddeley Harrier is a British jet-powered attack aircraft designed and produced by the British aerospace company Hawker Siddeley. It was the first operational ground attack and reconnaissance aircraft with vertical/short takeo ...

and the later

British Aerospace 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 serv ...

, a navalised fighter derivative of the former, was the adoption of an elevated cockpit within a bubble canopy, granting superior exterior visibility to the pilot.Bull 2004, p. 120. The

General Dynamics F-16 Fighting Falcon The General Dynamics F-16 Fighting Falcon is an American single-engine supersonic Multirole combat aircraft, multirole fighter aircraft originally developed by General Dynamics for the United States Air Force (USAF). Designed as an air superio ...

also adopted a frameless bubble canopy in conjunction with a raised and reclined seat that granted unobstructed forward and upward vision. The canopy of the F-16 comprises a single piece of bird-proof

polycarbonate Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate ester, carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, toughness, tough materials, and some grades are optically transp ...

; it lacks the forward bow frame found on many fighters, which is an obstruction to a pilot's forward vision."Lockheed Martin F-16 Fighting Falcon." ''Jane's All The World's Aircraft'', updated 21 January 2008. Retrieved: 30 May 2008. Bubble canopies were also incorporated into the

Lockheed Martin F-22 Raptor The Lockheed Martin/Boeing F-22 Raptor is an American Twinjet, twin-engine, Jet engine, jet-powered, Night fighter, all-weather, supersonic Stealth aircraft, stealth fighter aircraft. As a product of the United States Air Force's Advanced Ta ...

and the Eurofighter Typhoon, both being fighters oriented towards the aerial supremacy role. Specialised aerial reconnaissance aircraft have also made use of bubble canopies. The

Edgley Optica The Edgley EA-7 Optica is a British light aircraft designed for low-speed Surveillance aircraft, observation work, and intended as a low-cost alternative to helicopters. The Optica has a loiter speed of 130 km/h (70 kn; 81 mph) a ...

incorporates an unorthodox fully glazed forward cabin, intended to provide a high level of exterior vision to its crew; the aircraft has a distinctive appearance due to this cabin, often being referred to as the "bug-eye".''Flight International'' 12 May 1979, p. 1591. The bubble canopy has also been adopted within the

sector; the Diamond DA42 is one such aircraft which incorporates such a canopy in some guises, typically intended for reconnaissance work. Another general aviation aircraft, the Grob G 120, also features a relatively wide bubble-style canopy. Numerous aircraft within the general aviation category feature such canopies.

Purpose

The purpose of a bubble canopy is to give a pilot a much wider field-of-view than flush, framed "greenhouse" canopies used on early World War II aircraft, such as those seen on early models of the F4U, P-51, the Soviet Yak-1 and earlier, "razorback" P-47 fighters, all with dorsal "turtledecks" integral to their fuselage lines, which left a blind spot behind the pilot that enemy pilots could take advantage of to sneak up on an aircraft. The open-cockpit design combat aircraft of World War I had narrow fuselages, which often were not tall enough to block visibility to the rear, especially with seating positions that generally elevated the pilot's head well above the cockpit's edges. As planes became larger, heavier and faster, designs had to be made stronger, which often meant a taller rear fuselage, but designers tried to maintain the narrow fuselage for visibility. However, as speed continued to increase, it became necessary to enclose cockpits – and this, in turn, streamlined aircraft so that they were faster still. Increased "g-loading" during maneuvers forced pilots to wear tight, restrictive shoulder harnesses, and armor plating began to be installed to protect pilots from projectiles coming from behind. These changes denied a pilot the ability to twist around and look directly behind (known as "checking six," or looking at the "six o'clock" position directly to the rear). Mirrors offered some help, but had a narrow field of view. Prior to bubble canopies, some aircraft, such as the

P-40 Warhawk The Curtiss P-40 Warhawk is an American single-engined, single-seat, all-metal fighter-bomber that first flew in 1938. The P-40 design was a modification of the previous Curtiss P-36 Hawk which reduced development time and enabled a rapid entry ...

, featured a hybrid flush canopy design, combining a narrow rear fuselage with a glass enclosure conforming to the shape of a full-width fuselage - these often had a pair of recessed panels (one per side, behind the openable canopy) in the dorsal "turtledeck" structure, faired-in with framed glazing that was flush to the fuselage surface. This provided increased visibility while still allowing a pilot to keep the canopy closed for greater performance. Examples of such "recessed" rear vision designs were the "greenhouse"-canopied original F4U-1 Corsair as well as the P-40. The bulged Malcolm hood, used for the Spitfire, F4U Corsair, and P-51B and -C Mustangs was another hybrid. While not offering as much visibility to the rear as the P-40 enjoyed, it allowed a pilot more visibility than a flush canopy would.

Examples

File:Miles M.20.jpg, Miles M.20 showing the one-piece frame-less bubble canopy, the whole of which slides rearwards to open File:US Navy 040925-N-0295M-091 Retired U.S. Navy Capt. Dale Snodgrass takes off in his Korean War-era F-86 Sabre.jpg,

F-86 Sabre The North American F-86 Sabre, sometimes called the Sabrejet, is a transonic jet fighter aircraft. Produced by North American Aviation, the Sabre is best known as the United States' first swept-wing fighter that could counter the swept-wing Sov ...

File:SU-30 MKI Lajes.JPG, View of a Su-30 MKI canopy File:F-22 cockpit close-up.jpg, F-22 showing the frameless canopy and the 360° view for the pilot File:Mi-24 Polish.jpg, The twin bubble canopies of the

Hind helicopter File:Agusta AB-47G-2 D-HELO OTT 2013 01.jpg, Bell 47G helicopter with its distinctive "soap-bubble" canopy File:514th Fighter Squadron P-47 Thunderbolt 1945.jpg,

P-47 Thunderbolt The Republic P-47 Thunderbolt is a World War II-era fighter aircraft produced by the American company Republic Aviation from 1941 through 1945. It was a successful high-altitude fighter, and it also served as the foremost American fighter-bombe ...

File:Douglas XB-42A.jpg, Twin bubble canopies placed side by side rather than in

tandem Tandem, or in tandem, is an arrangement in which two or more animals, machines, or people are lined up one behind another, all facing in the same direction. ''Tandem'' can also be used more generally to refer to any group of persons or objects w ...

, seen on this XB-42A

References

Citations

Bibliography