Bubble canopy

A bubble canopy is a canopy made without bracing, which attempts to provide 360° vision to the pilot.

Bubble canopies have been in use since before World War II, with some experimental bubble canopy designs in the World War I era. The British had already developed the "Malcolm hood", which was a bulged canopy, but the British Miles M.20 was one of 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 utilised on other British aircraft, such as the Hawker Typhoon and Tempest. It was also later fitted to the P-51 Mustang and P-47 Thunderbolt amongst others. A well-framed version of an all-around vision canopy was also used on the Mitsubishi A6M Zero Japanese naval fighter, and different designs with much less framing than the "Zero" had, were used on the Imperial Japanese Navy Air Service's Nakajima Ki-43 Oscar and Nakajima Ki-84 Frank land-based fighter planes.

The Bell 47 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.

The purpose of a bubble canopy is to give a pilot a much wider field-of-view than flush, well-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 conspicuous blind spot behind the pilot that enemy pilots could take advantage of to sneak up on an aircraft.

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