Kawasaki Ki-45 Toryu (Dragon Slayer) 'Nick'

The Kawasaki Ki-45 Toryu (Dragon Slayer) was originally designed as a twin-engined heavy fighter in the same class as the Messerschmitt Bf 110, but saw most service as a ground-attack aircraft and night fighter.

The Ki-45 had a long development period. Kawasaki first began work on a twin-engined fighter, the Ki-38, in 1937, producing a design for a clean monoplane with elliptical wings, powered by two liquid-cooled engines. Work on this design was suspended late in 1937 while the Japanese Army staff decided exactly what sort of aircraft they wanted.

Kawasaki Ki-45 KAIc from below
Kawasaki Ki-45 KAIc from below

In December 1937 the Army issued Kawasaki with the new specification. The newly redesignated Ki-45 was to have a top speed of 335.5mph, an operating altitude of 6,560-16,405ft, an endurance of four hours and forty minutes at 217mph plus thirty minutes of combat, to be armed with two forward firing and one rear firing machine gun and to be powered by two 9-cylinder Nakajima Ha-20b radial engines (the Bristol Mercury built under licence).

Work on the new design began in January 1938, under the control of Takeo Doi. He produced a detailed design by October, and the first prototype was ready in January 1939. This aircraft used the Ha-20b engine, housed in large nacelles and with an exhaust collector ring in front of the engine. It was armed with two 7.7mm Type 89 machine guns in the upper nose, and a third flexible rear-firing gun, as well as a 20mm Ho-3 cannon in a ventral tunnel under the undercarriage.

The first prototype proved to be disappointing. The manually retracted undercarriage was unreliable, the engines failed to produce their rated power and the large nacelles caused too much drag.

Plans of Kawasaki Ki-45 KAI
Plans of Kawasaki Ki-45 KAI

A second prototype was completed with closer-fitting cowlings and propeller spinners, and a third with ducted spinners that supplied cooling air to the engines, but despite these changes the aircraft's top speed only reached 298mph, significantly below the Army's requirements. Late in 1939 work on the project was suspended for review.

In April 1940 the Army decided to revive the Ki-45, using new engines, this time the 1,000hp Nakajima Ha-25 two-row fourteen cylinder radial engine, with single-stage superchargers. This engine had a smaller diameter than the Ha-20b, allowing Kawasaki to use tight fitting NACA-type cowlings and smaller propeller spinners. This time the trials were a success, and an addition seven aircraft were completed to the same standard.

At the same time Takeo Doi was working on a improved version of the basic airframe. This has a slimmer fuselage, a redesigned tail, new wings with straight edges to replace the elliptical wing of the prototypes and smaller engine nacelles mounted lower on the wing. The nose guns were also changed from 7.7mm to 12.7mm Type I (Ho-103) guns. The prototype Ki-45 KAI was complete by May 1941, and was followed by two more prototypes and twelve pre-production aircraft.

The Ki-45 Kai solved most of the problems with the design, and was ordered into production late in 1941 as the Army Type 2 Two-seat Fighter Model A Toryu (Dragon Killer) or Ki-45 KAIa. 


The Ki-45 entered service with the 5th Sentai at Kasiwa, where it was preparing to move to New Guinea, but it entered combat with the 21st Sentai in Burma in October 1942, and then with the 16th Sentai in China in November.

The Ki-45 proved popular with its crews because of its heavy armament and protected fuel tanks. It was a successful ground attack and anti-shipping aircraft, but like the European aircraft that had originally inspired it was not a success as a long range fighter, suffering heavy losses when it came up against more manoeuvrable single-engined aircraft.

Kawasaki Ki-45 KAI with cannon pod
Kawasaki Ki-45 KAI with cannon pod

The Ki-45 was often seen over New Guinea, where it was used against American P.T. boats at sea, and against Allied tanks on land. It was also used as a night fighter against the wide-ranging B-24s of the US 5th Air Force, with some success.

The Ki-45 KAIc night fighter was used against the B-29 raids over Japan. On 15 June 1944, when XX Bomber Command launched its first raid on Japan, the B-29s were intercepted by eight Ki-45s, and eight aircraft were claimed to have been shot down (only seven B-29s were lost during this raid, at least two to other causes).

By the end of the war the Ki-45 equipped five night-fighter Sentai in Japan - the 4th, 53rd and at first the 5th in the Easter Defence Sector and the 45th, 70th and later 5th in the Middle Defence Sector.


Ki-45 KAIa/ Army Type 2 Two-seat Fighter Model A

The Ki-45 KAIa was the first production version of the aircraft, and was the standard heavy fighter version. It was armed with two 12.7mm guns in the nose, one 20mm cannon in the ventral tunnel and one 7.92mm rear-firing flexibly mounted machine gun.

Ki-45 KAIb/ Army Type 2 Two-seat Fighter Model B

The Ki-45 KAIb was a dedicated ground-attack and anti-shipping version of the aircraft, with increased firepower. The 12.7mm nose guns of the KAIa were replaced with a centrally mounted 20mm Ho-3 cannon, and a manually loaded 37mm Type 98 cannon was installed in the ventral tunnel. Early aircraft were otherwise identical to the KAIa, but late production aircraft were powered by two 1,080hp Mitsubishi Ha-102 engines, which improved reliability.

Ki-45 KAIc/ Army Type 2 Two-seat Fighter Model C

Kawasaki Ki-45 Kai in flight
Kawasaki Ki-45 Kai in flight

The Ki-45 KAIc produced as a night fighter. It was armed with a semi-automatic 37mm Ho-203 cannon with 16 rounds in the ventral tunnel and two obliquely mounted 20mm cannon in the central fuselage, but lost the nose guns, which were replaced with a pointed nose that was designed to carry radar. Only one Ki-45 KAIc was equipped with radar, and 477 aircraft were produced without it, starting in April 1944.

Ki-45 KAId

The Ki-45 KAId was an anti-shipping aircraft, armed with two 20mm Ho-5 cannon in the nose, one 37mm Ho-203 semi-automatic cannon in the ventral tunnel and one flexibly mounted 7.92mm Type 98 machine gun in the rear cockpit.


The Ki-45-II was the original designation for a version of the aircraft to be powered by two 1,500hp Mitsubishi Ha-112-II engines, but in December 1942 the Japanese Army decided to produce this aircraft as a single seater, and redesignated it as the Kawasaki Ki-96.


Kawasaki Ki-45 Kai being refuelled
Kawasaki Ki-45 Kai being refuelled

Ki-45 KAIa
Engine: Two Nakajima Ha-25 fourteen cylinder air cooled radial engines
Power (each): 1,050hp at take-off, 970hp at 11,115ft
Crew: 2 (pilot and radio-operator/ gunner)
Wing span: 49ft 3 5/16in
Length: 34ft 9 5/16in
Height: 12ft 1 11/16in
Empty Weight: 8,146lb
Loaded Weight: 11,632lb
Max Speed: 340mph at 22,965ft
Cruising Speed:
Service Ceiling: 35,200ft
Range: 1,404 miles
Armament: Two 12.7mm Type 1 machine guns in nose and one 7.92mm Type 98 machine gun in rear cockpit, plus on 20mm Ho-3 cannon in ventral tunnel
Bomb-load: Two 44 imperial gallon drop tanks or two 551lb bombs

Ki-45 KAIc
Engine: Two Mitsubishi Ha-102 fourteen-cylinder air-cooled radials
Power (each): 1,080hp at take-off, 1,050hp at 9,185ft, 950hp at 19,030ft
Crew: 2 (pilot and radio-operator/ gunner)
Wing span: 49ft 3 5/16in
Length: 36ft 1 1/16in
Height: 12ft 1 11/16in
Empty Weight: 8,818lb
Loaded Weight: 12,125lb
Max Speed: 335.5mph at 19,685ft
Cruising Speed:
Service Ceiling: 32,810ft
Range: 1,243 miles
Armament: One 37mm Ho-203 cannon in ventral tunnel, two obliquely mounted 20mm Ho-5 cannon in fuselage, one 7.92mm Type 98 machine gun in rear cockpit
Pay-load: Two 44 imperial gallon drop tanks or two 551lb bombs

Japanese Aircraft of World War II 1937-1945, Thomas Newdick. A useful shorter reference work looking at the combat aircraft fielded by the Japanese during the Second World War, along with those jet and rocket powered aircraft that got closest to being completed. A useful guide to the aircraft of the Japanese Army and Navy, a key element in the rapid expansion of Japanese power, and in the increasingly desperate defence of their expanded Empire as the war turned against them. Organised by type of aircraft, with enough information on each type for the general reader, and longer sections on key aircraft such as the Zero (Read Full Review)
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How to cite this article: Rickard, J (9 March 2010), Kawasaki Ki-45 Toryu (Dragon Slayer) 'Nick', http://www.historyofwar.org/articles/weapons_kawasaki_ki-45.html

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