The was a one-man ''

kamikaze , officially , were a part of the Japanese Special Attack Units of military aviators who flew suicide attacks for the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, intending to d ...

'' aircraft developed by the

Imperial Japanese Army Air Force The Imperial Japanese Army Air Service (IJAAS) or Imperial Japanese Army Air Force (IJAAF; ja, 大日本帝國陸軍航空部隊, Dainippon Teikoku Rikugun Kōkūbutai, lit=Greater Japan Empire Army Air Corps) was the aviation force of the Im ...

in the closing stages of

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

1945 1945 marked the end of World War II and the fall of Nazi Germany and the Empire of Japan. It is also the only year in which nuclear weapons have been used in combat. Events Below, the events of World War II have the "WWII" prefix. Januar ...

. The

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

called this aircraft Tōka (藤花, "

Wisteria ''Wisteria'' is a genus of flowering plants in the legume family, Fabaceae (Leguminosae), that includes ten species of woody twining vines that are native to China, Japan, Korea, Vietnam, Southern Canada, the Eastern United States, and north o ...

Blossom").

Historical context

The aircraft's intended purpose was to be used in ''kamikaze'' attacks on Allied shipping and the invasion fleet expected to be involved in the invasion of Japan,

Operation Downfall Operation Downfall was the proposed Allied plan for the invasion of the Japanese home islands near the end of World War II. The planned operation was canceled when Japan surrendered following the atomic bombings of Hiroshima and Nagasaki, th ...

, which in the end did not take place. Because the Japanese High Command thought that Japan did not have enough obsolete aircraft to use for ''kamikaze'' attacks, it was decided that huge numbers of cheap, simple suicide planes should be constructed quickly in anticipation of the invasion of Japan.

Construction

The aircraft was very simple, being made from "non-strategic" materials (mainly wood and steel). To save weight, it was to use a jettisonable undercarriage (there was to be no landing), so a simple welded steel tube undercarriage was attached to the aircraft.Tsurugi closeups. Col. Scott Wille
article
/ref> This, however, was found to give unmanageable ground-handling characteristics, so a simple

shock absorber A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated. Most sh ...

was then incorporated. The cross section of the

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 ...

was

circular Circular may refer to: * The shape of a circle * ''Circular'' (album), a 2006 album by Spanish singer Vega * Circular letter (disambiguation) ** Flyer (pamphlet), a form of advertisement * Circular reasoning, a type of logical fallacy * Circula ...

and not

elliptical Elliptical may mean: * having the shape of an ellipse, or more broadly, any oval shape ** in botany, having an elliptic leaf shape ** of aircraft wings, having an elliptical planform * characterised by ellipsis (the omission of words), or by conc ...

as were most planes of this size and type; such a fuselage was easier to make. ''Tsurugi'' had an instrument panel with some

flight instruments Flight instruments are the instruments in the cockpit of an aircraft that provide the pilot with data about the flight situation of that aircraft, such as altitude, airspeed, vertical speed, heading and much more other crucial information in fli ...

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

pedals, a joystick type control column and a place for a

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...

. Flight controls included both

ailerons An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in Flight dynamics, roll (or ...

and

elevators An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They are ...

and (in production versions)

flap Flap may refer to: Arts, entertainment, and media * ''Flap'' (film), a 1970 American film * Flap, a boss character in the arcade game ''Gaiapolis'' * Flap, a minor character in the film '' Little Nemo: Adventures in Slumberland'' Biology and he ...

s. The Ki-115 was designed to be able to use any engine that was in storage for ease of construction and supply, and to absorb Japan's stocks of obsolete engines from the 1920s and 1930s. The initial aircraft (Ki-115a) were powered by Nakajima Ha-35

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ca ...

s. It is not known if any other engine was ever actually fitted. After testing the first production aircraft were fitted with the improved undercarriage and two rocket units. These may have assisted with take-off or may have been designed for the final acceleration towards the target.Kamikaze and the Nakajima Ki 115 Tsurugi
/ref>

Performance

The aircraft had a top speed of and could carry a bomb weighing as much as , large enough to split a

warship A warship or combatant ship is a naval ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a state. As well as being armed, warships are designed to withstand damage and are usually faster a ...

in two. However, it was otherwise unarmed, and heavily laden with its bomb, would have been an easy target for enemy

fighter aircraft Fighter aircraft are fixed-wing military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air superiority of the battlespace. Domination of the airspace above a battlefield ...

. The controls were crude, the visibility terrible, and the performance abysmal. ''Tsurugi'' had very poor take-off and landing performance and could not be safely flown by anyone other than experienced pilots. There were fatal crashes during testing and training. However new, better versions with improved controls and better visibility were under intensive development. The Japanese High Command had plans to construct some 8,000 per month in workshops all across Japan. The war ended before any flew in combat. Individually, they would have been rather inefficient weapons, but used in waves of hundreds or thousands they could have been quite destructive.

Variants

* Ki-115 Tsurugi: Single-seat suicide attack aircraft, production version. * Ki-230: Single-seat suicide attack aircraft. projected version, none built.

Surviving aircraft

Of the 105 examples produced, two airframes are known to exist. One example of the Ki-115 on loan to the

Pima Air & Space Museum The Pima Air & Space Museum, located in Tucson, Arizona, is one of the world's largest non-government funded aerospace museums. The museum features a display of nearly 300 aircraft spread out over 80 acres (320,000 m²) on a campus occ ...

Tucson, Arizona , "(at the) base of the black ill , nicknames = "The Old Pueblo", "Optics Valley", "America's biggest small town" , image_map = , mapsize = 260px , map_caption = Interactive map ...

from the

National Air and Space Museum The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C., in the United States. Established in 1946 as the National Air Museum, it opened its main building on the Nat ...

. Another, once displayed as a

gate guardian A gate guardian or gate guard is a withdrawn piece of equipment, often an aircraft, armoured vehicle, artillery piece, or locomotive, mounted on a plinth and used as a static display near to and forming a symbolic display of "guarding" the main ...

Yokota Air Base , is a Japan Air Self-Defense Force (JASDF) and United States Air Force (USAF) base in the Tama Area, or Western Tokyo. It occupies portions of Akishima, Fussa, Hamura, Mizuho, Musashimurayama, and Tachikawa. The base houses 14,000 personnel ...

, was since 1952 turned over to Japanese authorities and is reportedly at a Japanese museum.

Specifications (Ki-115a)

References

;Notes ;Bibliography * (new edition 1987 by Putnam Aeronautical Books, .) * Gunston, Bill. ''The Illustrated Encyclopedia of Combat Aircraft of World War II'' London: Salamander Books, Ltd., 1978. .

External links

{{Imperial Japanese Navy official aircraft names Ki-115, Nakajima Ki-115, Nakajima Ki-115 Single-engined tractor aircraft Low-wing aircraft Aircraft first flown in 1945