The Nakajima C6N ''Saiun'' (彩雲, "

Iridescent Cloud Cloud iridescence or irisation is a colorful optical phenomenon that occurs in a cloud and appears in the general proximity of the Sun or Moon. The colors resemble those seen in soap bubbles and oil on a water surface. It is a type of photom ...

") was a carrier-based

reconnaissance aircraft A reconnaissance aircraft (colloquially, a spy plane) is a military aircraft designed or adapted to perform aerial reconnaissance with roles including collection of imagery intelligence (including using photography), signals intelligence, as ...

used by the Imperial Japanese Navy Air Service in

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 ...

. Advanced for its time, it was the fastest

carrier-based aircraft Carrier-based aircraft, sometimes known as carrier-capable aircraft or carrier-borne aircraft, are naval aircraft designed for operations from aircraft carriers. They must be able to launch in a short distance and be sturdy enough to withstand ...

put into service by

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

during the war. The

Allied An alliance is a relationship among people, groups, or states that have joined together for mutual benefit or to achieve some common purpose, whether or not explicit agreement has been worked out among them. Members of an alliance are called ...

reporting name NATO reporting names are code names for military equipment from Russia, China, and historically, the Eastern Bloc (Soviet Union and other nations of the Warsaw Pact). They provide unambiguous and easily understood English words in a uniform manne ...

was ''Myrt''.

Development and design

The C6N originated from a 1942

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 ...

specification for a carrier-based

reconnaissance In military operations, reconnaissance or scouting is the exploration of an area by military forces to obtain information about enemy forces, terrain, and other activities. Examples of reconnaissance include patrolling by troops (skirmisher ...

plane Plane(s) most often refers to: * Aero- or airplane, a powered, fixed-wing aircraft * Plane (geometry), a flat, 2-dimensional surface Plane or planes may also refer to: Biology * Plane (tree) or ''Platanus'', wetland native plant * ''Planes' ...

with a top speed of 350

knot A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ' ...

s (650 km/h) at 6,000 m and range of 2,500

nautical mile A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today ...

s (4,960 km).Francillon 1970, p. 434. Nakajima's initial proposal, designated N-50, was for a craft with two engines housed in tandem in the fuselage, driving two propellers mounted on the wings. With the development of the class

Nakajima Homare The Nakajima Homare (誉, "praise" or, more usually, "honour") was an air-cooled twin-row 18 cylinder radial Japanese aircraft engine manufactured during World War II. Producing almost 2,000 horsepower, it was used widely by both the Imperial ...

engine, the dual powerplant configuration was abandoned and Nakajima decided on a more conventional single-engine layout. Unfortunately the new Homare's

power output Power most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may ...

was less than expected, and the design had to be optimized in other areas. The resulting aircraft was designed around a long and extremely narrow cylindrical

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 ...

just large enough in diameter to accommodate the engine. The

crew A crew is a body or a class of people who work at a common activity, generally in a structured or hierarchical organization. A location in which a crew works is called a crewyard or a workyard. The word has nautical resonances: the tasks involve ...

of three sat in tandem under a single

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...

, while equipment was similarly arranged in a line along the fuselage. The C6N's low-mounted laminar flow wing housed fuel tanks and was fitted with both Fowler and slit

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 and

leading-edge slat Slats are aerodynamic surfaces on the leading edge of the wing of a fixed-wing aircraft which, when deployed, allow the wing to operate at a higher angle of attack. A higher coefficient of lift is produced as a result of angle of attack and speed, ...

s which lowered the aircraft's landing speed to ease use aboard

aircraft carrier An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...

s.Francillon 1970, p. 435. Like Nakajima's earlier B6N ''Tenzan'' torpedo bomber, the

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 ...

was angled slightly forward to enable tighter packing on aircraft carrier decks. The C6N's first flight was on 15 May 1943, with the prototype demonstrating a speed of .Francillon 1970, p. 436. Performance of the Homare engine was disappointing, especially its power at altitude, and a series of 18 further prototypes and pre-production aircraft were built before the ''Saiun'' was finally ordered into production in February 1944.Mondey 1996, p. 218.

Operational history

Although designed for carrier use, by the time it entered service in September 1944 there were few carriers left for it to operate from, so most C6Ns were flown from land bases. Its speed was exemplified by a telegraph sent after a successful mission: "No

Grumman The Grumman Aircraft Engineering Corporation, later Grumman Aerospace Corporation, was a 20th century American producer of military and civilian aircraft. Founded on December 6, 1929, by Leroy Grumman and his business partners, it merged in 1994 ...

s can catch us." ("我に追いつくグラマンなし"). The top speed of the Hellcat was indeed of the same level, so overtaking a ''Saiun'' was out of the question.Francillon 1979, p. 40. A total of 463 aircraft were produced. A single prototype of a turbocharged development mounting a 4-blade propeller was built; this was called the C6N2 ''Saiun-kai''. Several examples of a

night fighter A night fighter (also known as all-weather fighter or all-weather interceptor for a period of time after the Second World War) is a fighter aircraft adapted for use at night or in other times of bad visibility. Night fighters began to be used i ...

version C6N1-S with oblique-firing (''

Schräge Musik ''Schräge Musik'', which may also be spelled ''Schraege Musik'', was a common name for the fitting of an upward-firing autocannon or machine gun, to an interceptor aircraft, such as a night fighter. The term was introduced by the German ''L ...

'' configuration) single 30 mm (or dual 20 mm) cannon were converted from existing C6N1s. As Allied bombers came within reach of the Japanese home islands, a first class night fighter was required. This led Nakajima to develop the C6N1-S by removing the observer and replacing him with two 20 mm cannons. The C6N1-S's effectiveness was hampered by the lack of air-to-air

radar Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...

, although it was fast enough to enjoy almost complete immunity from interception by

fighters. A torpedo carrying C6N1-B was also proposed, but was not needed after most of Japan's aircraft carriers were destroyed. Despite its speed and performance, on 15 August 1945 a C6N1 happened to be the last aircraft to be shot down in

. Just five minutes later, the war was over and all Japanese aircraft were grounded.

Variants

''Source:''Famous Airplanes of the WorldFamous Airplanes of the World (2005), p. 21–27 ;C6N1 ''Experimental Type 17 carrier reconnaissance plane'' (17試艦上偵察機, ''17-Shi Kanjō Teisatsuki'') :Three prototypes and sixteen supplementary prototypes produced, four-blade propeller; latter batch were equipped three-blade

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

, mounted Nakajima NK9K-L Homare 22 engine, No. 6 was mounted Nakajima NK9H Homare 21 engine. Renamed ''Test production Saiun'' (試製彩雲, ''Shisei Saiun'') in July 1943. ;C6N1 ''Saiun Model 11'' (彩雲11型, ''Saiun 11-gata'') :General production model. Three-blade propeller, mounted Nakajima NK9H Homare 21 engine. :;C6N1-B ''Saiun Model 21'' (彩雲21型, ''Saiun 21-gata'') ::Proposed

torpedo bomber A torpedo bomber is a military aircraft designed primarily to attack ships with aerial torpedoes. Torpedo bombers came into existence just before the First World War almost as soon as aircraft were built that were capable of carrying the weight ...

version. Only a project. :;C6N1 ''Saiun Model 11 night fighter variant'' (彩雲11型改造夜戦, ''Saiun 11-gata Kaizō yasen'') ::Temporary rebuilt two-seat

version; this was not a regulation naval aircraft. Development code ''C6N1-S'' was not discovered in the IJN official documents. One model with a singular 30 mm Type 5 cannon and at least five models with ×2 20 mm Type 99-1 cannon were converted from standard C6N1 models. One surviving example of the ×2 20mm cannon variant is stored in the ''

Paul E. Garber Preservation, Restoration, and Storage Facility The Paul E. Garber Preservation, Restoration, and Storage Facility, also known colloquially as "Silver Hill", is a storage and former conservation and restoration facility of the Smithsonian National Air and Space Museum, located in Suitland, Ma ...

''. ;C6N2 ''Test production Saiun Kai/Saiun Model 12'' (試製彩雲改/彩雲12型, ''Shisei Saiun Kai/Saiun 12-gata'') :Fitted with four-blade propeller, 1,980-hp (1,476-kW) Nakajima NK9K-L Homare 24-Ru turbocharged engine. Two

prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototyp ...

s were converted from regular C6N1 models in February 1945. ;C6N3 ''Test production Saiun Kai 1'' (試製彩雲改1, ''Shisei Saiun Kai 1'') :Proposed high-altitude night fighter version of the C6N2. Dual 20 mm cannons were installed. Only a project. ;C6N4 ''Test production Saiun Kai 2'' (試製彩雲改2, ''Shisei Saiun Kai 2'') :Fitted 2,200-hp Mitsubishi MK9A Ha 43-11 Ru turbocharged engine, one prototype was converted from C6N1, incomplete. ;C6N5 ''Test production Saiun Kai 3'' (試製彩雲改3, ''Shisei Saiun Kai 3'') :Proposed torpedo bomber version. Only a project. ;C6N6 ''Test production Saiun Kai 4'' (試製彩雲改4, ''Shisei Saiun Kai 4'') :Wooden aircraft model. Only a project.

Operators

;Famous Airplanes of the World (2005), p. 56–63Model Art (1995), pp. 61–64, p. 148 * Imperial Japanese Navy Air Service *Naval Air Group **Yokosuka

Kōkūtai A ''Kōkūtai'' () was a term used by the Imperial Japanese Navy Air Service (IJNAS) to designate a military aviation unit, similar to the Air Groups in other air arms and services of the time. (''Group'' in the British Royal Air Force, ''Grupp ...

**121st Kōkūtai **131st Kōkūtai **132nd Kōkūtai **141st Kōkūtai **171st Kōkūtai **210th Kōkūtai **302nd Kōkūtai **343rd Kōkūtai **701st Kōkūtai **723rd Kōkūtai **752nd Kōkūtai **762nd Kōkūtai **801st Kōkūtai **1001st Kōkūtai *Aerial Squadron **Reconnaissance 3rd Hikōtai **Reconnaissance 4th Hikōtai **Reconnaissance 11th Hikōtai **Reconnaissance 12th Hikōtai **Reconnaissance 102nd Hikōtai *

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 ...

**1st Mitate Special Attack Group (picked from 752nd Kōkūtai) **Sairyū Unit (picked from 752nd Kōkūtai, no sorties) **Saiun Unit (picked from 723rd Kōkūtai, no sorties)

Specifications (C6N1)

Notes

Bibliography

* Francillon, René J. ''Japanese Aircraft of the Pacific War''. London: Putnam & Company Ltd., 1970. (2nd edition 1979, ). * Francillon, René J. ''Japanese Carrier Air Groups, 1941–45''. London; Osprey Publishing Ltd., 1979. . * * Mondey, David. ''The Concise Guide to Axis Aircraft of World War II''. London: Chancellor Press, 1996. .

External links

* {{Allied reporting names Low-wing aircraft Carrier-based aircraft C6N, Nakajima World War II Japanese reconnaissance aircraft Single-engined tractor aircraft Aircraft first flown in 1943