Японский истребитель Второй мировой войны Ki-61 "Тони"

WWII Japanese Fighter Aircraft

type = Fighter aircraft
manufacturer = Kawasaki Kōkūki Kōgyō K. K.
designer =
first flight = December 1941
introduced = 1942
retired = 1945
status =
primary user = Imperial Japanese Army Air Service
more users = Chinese Nationalist Air Force, Indonesian Air Force, People's Liberation Army Air Force
produced =
number built = 3,078 Allied intelligence initially believed Ki 61s were Messerschmitt Bf 109s and later an Italian Macchi C.202, which led to the Allied reporting name of "Tony", assigned by the United States War Department. The design originated as a variant of the Kawasaki Ki 60, which never entered production. The Ki 61 became the only mass produced Japanese fighter of the war to use a liquid cooled inverted V engine. Over 3,000 Ki 61s were produced. Initial prototypes saw action over Yokohama during the Doolittle Raid on 18 April 1942, and continued to fly combat missions throughout the war. Design and development
The Ki 61 was designed by Takeo Doi and his deputy Shin Owada in response to a late 1939 tender by the Koku Hombu for two fighters, each to be built around the Daimler Benz DB 601Aa. Production aircraft would use a Kawasaki licensed DB 601, known as the Ha 40, which was to be manufactured at its Akashi plant. The Ki 60 was to be a heavily armed specialised interceptor, with a high wing loading; the Ki 61 was to be a more lightly loaded and armed general purpose fighter, intended to be used mainly in an offensive, air superiority role at low to medium altitudes. Both single seat, single engine fighters used the same basic construction: all metal alloys with semi monocoque fuselages and three spar wings, with alloy framed, fabric covered ailerons, elevators and rudders. Priority was given to the Ki 60, which first flew in April 1941, while design work on the Ki 61 did not begin until December 1940. Although the Ki 61 was broadly similar to the Ki 60, it featured several refinements exploiting lessons learned from the disappointing flight characteristics of the earlier design. The all metal, semi monocoque fuselage was basically oval in cross section, changing to a tapered, semi triangular oval behind the cockpit canopy, with a maximum depth of 1.35 m (4 ft 5 in). An unusual feature of the Ki 61 was that the engine bearers were constructed as an integral part of the forward fuselage, with the cowling side panels being fixed. For servicing or replacement, only the top and bottom cowling panels could be removed. A tapered, rectangular supercharger air intake was located on the port side cowling. Behind the engine bulkhead were the ammunition boxes feeding a pair of synchronized 12.7 mm (.50 in) Ho 103 machine guns which were set in a "staggered" configuration (the port weapon slightly further forward than that to starboard) in a bay just above and behind the engine. The breeches partly projected into the cockpit, above the instrument panel. The Ho 103 was a light weapon for its caliber (around 23 kg/51 lb) and fired a light shell, but this was compensated for by its rapid rate of fire. The ammunition capacity was limited, having only around 250 rounds for each weapon. A self sealing fuel tank with a capacity of 165 L (44 US gal) was located behind the pilot's seat. The windshield was armored and there was a 13 mm (.51 in) armor plate behind the pilot. The radiator and oil cooler for the liquid cooled engine were in a ventral location below the fuselage and wing trailing edge, covered by a rectangular section fairing with a large, adjustable exit flap. Although test pilots were enthusiastic about its self sealing fuel tanks, upgraded armament, and good dive performance, the wing loading of 146.3 kg/m2 (30 lb/ft2) at an all up weight of 2,950 kg (6,500 lb) was viewed with scepticism by many of the senior officers of the Koku Hombu, who still believed in the light, highly manoeuvrable, lightly armed fighter epitomised by the then new Nakajima Ki 43 I Hei which had a wing loading of 92.6 kg/m2 (19 lb/ft2) (and even that was considered borderline compared to the earlier Ki 27). To address these concerns, Kawasaki staged a fly off between two Ki 61 prototypes and the Nakajima Ki 43 I, a pre production Nakajima Ki 44 I, a defector flown Lavochkin Gorbunov Goudkov LaGG 3, a Messerschmitt Bf 109E 7, and a captured Curtiss P 40E Warhawk. The Ki 61 proved the fastest of all the aircraft and was inferior only to the Ki 43 in manoeuvrability. The Ki 61 was the last of the fighters powered by the DB 601 or its foreign derivatives, and it was soon overshadowed by fighters with more powerful engines. By the time it first flew in December 1941, one year after the Macchi C.202's first flight and three years after the first Bf 109E, the engine was already underpowered compared to the new 1,120 kW (1,500 hp) inline or 1,491 kW (2,000 hp) radial engines being developed (and already nearing the mass production stage) to power the next generation of combat aircraft such as the Republic P 47 Thunderbolt. Moreover, the inline Ha 40 engine proved to be an unreliable powerplant, exacerbated in the South Pacific campaign, where high temperatures caused problems with the fuel pumps. The DB 601 engine required precise and sophisticated manufacturing; the Ha 40 was lighter by roughly 30 kg (70 lb) and required even higher manufacturing standards. Reaching these standards proved difficult for Japanese manufacturers, an issue further complicated by the variable quality of materials, fuel, and the lubricants needed to run a sensitive, high performance engine. The Japanese equivalent of the more powerful DB 605 engine was the Kawasaki Ha 140, which was fitted onto the Type 3 to produce the Ki 61 II high altitude interceptor. Compared to the Ki 61 I, the Ki 61 II had 10% greater wing area, used more armour and was powered by the Kawasaki Ha 140 engine generating 1,120 kW (1,500 hp). After overcoming initial fuselage and wing stability problems, the new interceptor reverted to the original wing and was put into service as the Ki 61 II KAI. However, the Ha 140 engine had severe reliability problems that were never fully resolved, and around half of the first batch of engines delivered were returned to the factory to be re built. A US bombing raid on 19 January 1945 destroyed the engine factory in Akashi, Hyōgo, and 275 Ki 61 II KAI airframes without engines were converted to use the Mitsubishi Ha 112 II radial engine, resulting in the Ki 100. While the Ha 112 solved the problems encountered with the Ha 140, the new engine still had a major weakness: a lack of power at altitude, which diminished its ability to intercept high flying B 29 Superfortresses relative to the Ki 61 II. During testing, the Hien proved capable, but several shortcomings were subsequently revealed in operational service, namely the armor protection that was insufficient against larger guns and a sub standard engine that eventually led to a new engine being considered. Operational history

The Ki 61 looked so different from the usual radial engined Japanese fighters that the Allies at first believed it to be of German or Italian origin, possibly a license built Messerschmitt Bf 109. The first Ki 61 seen by Allied aircrew had been misidentified as a Bf 109 by USAAF Capt. C. Ross Greening during the Doolittle Raid. In early reports, when it was thought to have been a German fighter, the Ki 61 had been code named "Mike". The new Ki 61 Hien fighters entered service with a special training unit, the 23rd Chutai, and entered combat for the first time in early 1943, during the New Guinea campaign. The first Sentai (Air Group/Wing) fully equipped with the Hien was the 68th in Wewak, New Guinea, The finicky Ha 40 engine could not be overhauled in the theatre, instead they had to be shipped to the nearest service depot in Halmahera, in eastern Indonesia. By the end of the campaign, nearly 2,000 Japanese aircraft had been lost in air attacks from up to 200 Allied aircraft at a time, around half of which were Consolidated B 24 Liberators and North American B 25 Mitchells armed with fragmentation bombs. The Ki 61 carried a great deal of fuel, but due to having self sealing fuel tanks it was not considered readily flammable, as many other Japanese aircraft were. Owing to the additional weight, the Ki 61's performance and agility suffered when its armament was increased, but it still remained capable with a 580 km/h (313 kn) maximum speed. The cannon armament was needed to counter the Allied bombers, which proved to be difficult to shoot down with only 12.7 mm (.50 in) machine guns. The empty and maximum weights for the Ki 61 prototype (2 × 12.7 mm/0.50 in + 2 × 7.7 mm/0.303 in) were 2,238 kg (4,934 lb) and 2,950 kg (6,504 lb), respectively; for the Ki 61 I basic (4 × 12.7 mm/.50 in) 3,130 kg (6,900 lb); and for the Ki 61 KAI (2 × 12.7 mm/0.50 in + 2 × 20 mm), 2,630 kg (5,798 lb) and 3,470 kg (6,750 lb). Ki 61 Special Attack Unit

The tactic of using aircraft to ram American Boeing B 29 Superfortresses was first recorded in late August 1944, when B 29s from Chinese airfields attempted to bomb the steel factories at Yawata. Sergeant Shigeo Nobe of the 4th Sentai intentionally flew his Kawasaki Ki 45 into a B 29; debris from the explosion severely damaged another B 29, which also went down. Other attacks of this nature followed, as a result of which individual pilots determined it was a practicable way of destroying B 29s. On 7 November 1944, the officer commanding the 10th Hiko Shidan (Air division) made ramming attacks a matter of policy by forming ramming attack flights specifically to oppose the B 29s at high altitude. The aircraft were stripped of their fuselage armament and protective systems in order to attain the required altitudes. Although the term "kamikaze" is often used to refer to the pilots undertaking these attacks, the word was not used by the Japanese military. The units assigned to the 10th Hiko Shidan included the 244th Hiko Sentai (Fighter group), then commanded by Captain Takashi Fujita, who organised a ramming flight called "Hagakure Tai" ("Special Attack Unit"), which was composed out of volunteers from the three Chutai (squadrons) of the 244th: the 1st Chutai "Soyokaze", 2nd Chutai "Toppu", and the 3rd Chutai known as "Mikazuki". First Lieutenant Toru Shinomiya was selected to lead the Hagakure Tai. On 3 December 1944, Shinomiya – along with Sergeant Masao Itagaki and Sergeant Matsumi Nakano – intercepted a B 29 raid; Shinomaya rammed one B 29, but was able to land his damaged Ki 61, which had lost most of the port outer wing, back at base. After attacking another B 29 Itagaki had to parachute from his damaged fighter, while Nakano rammed and damaged Long Distance of the 498th BG and crash landed his stripped down Ki 61 in a field. Shinomaya's damaged Ki 61 was later displayed inside Tokyo's Matsuya department store while Nakano's Ki 61 was displayed outside, alongside of a life size cut away drawing of the forward fuselage of a B 29. These three pilots were the first recipients of the Bukosho, Japan's equivalent to the Victoria Cross or Medal of Honor, which had been inaugurated on 7 December 1944 as an Imperial Edict by Emperor Hirohito (there are 89 known recipients, most of whom fought and scored against B 29s). The existence of the ramming unit had been kept confidential until then, but it was officially disclosed in the combat results announcement and officially named "Shinten Seiku Tai" ("Body Attack Detachment") by the Defense GHQ. On 27 January 1945, Itakagi survived another ramming attack on a B 29, again parachuting to safety, and received a second Bukosho; he survived the war as only one of two known double Bukosho recipients. Sergeant Shigeru Kuroishikawa was another distinguished member of the unit. Despite their successful attacks, these pilots gained no reprieve, and were obliged to continue these deadly and dangerous ramming tactics until they were killed, or else wounded so badly that they could no longer fly. They were regarded as doomed men and were celebrated among the ranks of those who were going to certain death as Tokkotai (kamikaze) pilots. Some other Ki 61 pilots also achieved renown, among them Major Teruhiko Kobayashi of the 244th Sentai, who was credited by some with a dozen victories mostly due to conventional attacks against B 29s. Variants
Note: Ko, Otsu, Hei and Tei are the Japanese equivalents to a, b, c, d. Kai ('modified' or 'improved') was also used for some models of the Ki 61. Ki 61 Hien
Ki 61 Prototypes: 12 built
Ki 61 I Ko First production version: fully retractable tailwheel, two 7.7 mm (0.303 in) Type 89 machine guns in the wings and two synchronized 12.7 mm (0.50 in) Ho 103 machine guns in the forward decking. Capable of carrying one 151 L (40 gal) drop tank or a light bomb. Year Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Annual 1942 1 3 5 10 15 34 1943 22 32 31 37 44 40 53 60 70 87 104 130 710 1944 150 156 145 142 118 236 254 198 164 174 101 53 1,891 1945 19 19 Total 2,654

Not included:

Pre production started with the first prototype completed in July 1941, and with further eleven builds in early 1942. +Ki 61 II Production: Kawasaki Kokuki K. K

Not included:

Pre production started with eight prototypes completed during Aug. 1943 to Jan. 1944. Most aircraft were destroyed in military conflicts between the Netherlands and the newly proclaimed Republic of Indonesia during the Indonesian National Revolution of 1945–1949. Sentai Established Aircraft type(s) Area of operations Disbanded Notes 17th 10 February 1944 at Kagamigahara, Gifu Prefecture Ki 61, Ki 100 Philippines, Formosa, Japan End of war One of Kawasaki's main factories was located at Kagamigahara which, in 1944 was not yet a city. 18th 10 February 1944 at Chōfu from the 244th Sentai Ki 61, Ki 100 Philippines, Japan End of War Lt Mitsuo Oyake won Bukosho for shooting down three B 29s (one by ramming) 7 April 1945 and damaging three others. 19th 10 February 1944 at Akeno Fighter School Ki 61 Indonesia, Philippines, Formosa, Okinawa End of War (Formosa) 23rd 11 October 1944 at Inba, Chiba Prefecture Ki 43, Ki 44, Ki 61 Iwo Jima, Formosa, Japan End of war (Inba) 26th Late 1944 Ki 51, Ki 43, Ki 61 Formosa End of war (Formosa) 28th June 1939 in Manchuria Ki 46, Ki 61, Ki 102 Manchuria, Japan July 1945 31st July 1938 in China Ki 10, Ki 43, Ki 61Manchuria, Philippines 30 May 1945 at Singapore 33rd Summer 1937 in China Ki 10, Ki 27, Ki 43, Ki 61 New Guinea, Manchuria (Manchoukuo), East Indies End of war, Medan, Dutch East Indies (currently Indonesia) 53rd 23 March 1944 at Tokorozawa, Saitama Ki 61, Ki 45 Japan, Eastern Defence Sector flew Ki 61 for a short time in Home Island Defence 55th 30 May 1944 at Taishō, Osaka Prefecture Ki 61 Philippines, Japan End of war at Sana, Nara Prefecture 56th August 1944 at Taishō Osaka Prefecture Ki 61 Japan End of war at Itami, Hyōgo Prefecture Unit claimed 11 B 29s for 30 pilots lost. Warrant Officer Tadao Sumi (five B 29s plus one P 51 Mustang destroyed, four B 29s damaged) Bukosho recipient. 59th 1 July 1938 at Kagamigahara, Gifu Prefecture Ki 10, Ki 27, Ki 43, Ki 61, Ki 100 China, Manchuria (Nomonhan), Indochina, East Indies, New Guinea, Okinawa, Japan End of War at Ashiya, Fukuoka Prefecture 1st Lieutenant Naoyuki Ogata Bukosho recipient. Warrant Officer Kazuo Shimizu flew with unit from February 1942 right through to August 1945; 18 victories, including nine bombers. 65th presumably 1938 1939 Ki 32, Ki 51, Ki 43, Ki 61, Ki 45 Philippines, Formosa, Okinawa, Japan End of war, Metabaru, Saga Unit used Ki 61 from the summer of 1944 68th March 1942 at Harbin, Manchuria Ki 27, Ki 61 Rabaul (New Britain), New Guinea, Halmahera 25 July 1944 First unit to convert to the Ki 61. Unit was destroyed by Allied air forces in New Guinea. Most surviving ground and aircrew were used as infantry, with few survivors. A Ki 61 1 Otsu, manufacturer's No. 640 is one of the best preserved aircraft wrecks in New Guinea. Captain Shogo Takeuchi transferred from 64th Sentai, April 1942. KIA 15 December 1943 30+ victories. Sgt. Susumu Kaijinami officially credited with eight victories plus 16 unofficially. 78th 31 March 1942 in ChinaKi 27, Ki 61Manchuria, Rabaul, New Guinea 25 July 1944 Second unit to convert to the Ki 61. Unit was destroyed by Allied air forces in New Guinea. Most surviving ground and aircrew were used as infantry, with few survivors. 105th August 1944, Taichung, Formosa Ki 61Okinawa, Formosa End of war (Formosa) 244th April 1942, reorganised from 144th SentaiKi 27, Ki 61, Ki 100Okinawa, Formosa End of war (Yokaichi, Shiga Prefecture) Nine Bukosho recipients. Major Teruhiko Kobayashi JAAF's youngest Sentai commander. Also had an air to air B 29 ramming unit. Sentai claimed 73 B 29s shot down plus 92 damaged. Most famous of the Home Defence Sentais. Captain Nagao Shirai considered the ranking ace of 244 Sentai and possibly leading B 29 "killer" of JAAF (11 B 29s) plus two Grumman F6F Hellcats destroyed, six other aircraft damaged using Ki 61 and Ki 100. Captain Chuichi Ichikawa nine B 29s plus one F6F destroyed, six B 29s damaged. Major Teruhiko Kobayashi, three B 29s plus two F6Fs destroyed. Training units 23rd Dokuritsu Dai Shijugo (Independent Chutai) Chōfu, 1941Ki 61Japan Became basis of 23rd Sentai Evaluation and conversion unit for Ki 61. Akeno Kyodo Hikoshidan (Akeno Flight School) Akeno, Mie Prefecture, 1935Ki 10, Ki 27, Ki 43, Ki 44, Ki 45, Ki 61, Ki 84, Ki 100Japan End of war Main flight training school for Army fighter pilots. Many of the instructors participated in missions in defence of Japan 1944–1945. Akeno Airbase still in operational use. 37th Kyoiku Hikōtai (Flight Training Company) Matsuyama airfield, Formosa, 1943 Ki 43, Ki 44, Ki 45, Ki 61, Ki 84 Formosa End of war Flight training school for Army fighter pilots. Many of the instructors participated in missions in defence of Japan 1944 1945

WWII Japanese Fighter Aircraft

type = Fighter aircraft
manufacturer = Kawasaki Kōkūki Kōgyō K. K.
designer =
first flight = December 1941
introduced = 1942
retired = 1945
status =
primary user = Imperial Japanese Army Air Service
more users = Chinese Nationalist Air Force, Indonesian Air Force, People's Liberation Army Air Force
produced =
number built = 3,078 Allied intelligence initially believed Ki 61s were Messerschmitt Bf 109s and later an Italian Macchi C.202, which led to the Allied reporting name of "Tony", assigned by the United States War Department. The design originated as a variant of the Kawasaki Ki 60, which never entered production. The Ki 61 became the only mass produced Japanese fighter of the war to use a liquid cooled inverted V engine. Over 3,000 Ki 61s were produced. Initial prototypes saw action over Yokohama during the Doolittle Raid on 18 April 1942, and continued to fly combat missions throughout the war. Design and development
The Ki 61 was designed by Takeo Doi and his deputy Shin Owada in response to a late 1939 tender by the Koku Hombu for two fighters, each to be built around the Daimler Benz DB 601Aa. Production aircraft would use a Kawasaki licensed DB 601, known as the Ha 40, which was to be manufactured at its Akashi plant. The Ki 60 was to be a heavily armed specialised interceptor, with a high wing loading; the Ki 61 was to be a more lightly loaded and armed general purpose fighter, intended to be used mainly in an offensive, air superiority role at low to medium altitudes. Both single seat, single engine fighters used the same basic construction: all metal alloys with semi monocoque fuselages and three spar wings, with alloy framed, fabric covered ailerons, elevators and rudders. Priority was given to the Ki 60, which first flew in April 1941, while design work on the Ki 61 did not begin until December 1940. Although the Ki 61 was broadly similar to the Ki 60, it featured several refinements exploiting lessons learned from the disappointing flight characteristics of the earlier design. The all metal, semi monocoque fuselage was basically oval in cross section, changing to a tapered, semi triangular oval behind the cockpit canopy, with a maximum depth of 1.35 m (4 ft 5 in). An unusual feature of the Ki 61 was that the engine bearers were constructed as an integral part of the forward fuselage, with the cowling side panels being fixed. For servicing or replacement, only the top and bottom cowling panels could be removed. A tapered, rectangular supercharger air intake was located on the port side cowling. Behind the engine bulkhead were the ammunition boxes feeding a pair of synchronized 12.7 mm (.50 in) Ho 103 machine guns which were set in a "staggered" configuration (the port weapon slightly further forward than that to starboard) in a bay just above and behind the engine. The breeches partly projected into the cockpit, above the instrument panel. The Ho 103 was a light weapon for its caliber (around 23 kg/51 lb) and fired a light shell, but this was compensated for by its rapid rate of fire. The ammunition capacity was limited, having only around 250 rounds for each weapon. A self sealing fuel tank with a capacity of 165 L (44 US gal) was located behind the pilot's seat. The windshield was armored and there was a 13 mm (.51 in) armor plate behind the pilot. The radiator and oil cooler for the liquid cooled engine were in a ventral location below the fuselage and wing trailing edge, covered by a rectangular section fairing with a large, adjustable exit flap. Although test pilots were enthusiastic about its self sealing fuel tanks, upgraded armament, and good dive performance, the wing loading of 146.3 kg/m2 (30 lb/ft2) at an all up weight of 2,950 kg (6,500 lb) was viewed with scepticism by many of the senior officers of the Koku Hombu, who still believed in the light, highly manoeuvrable, lightly armed fighter epitomised by the then new Nakajima Ki 43 I Hei which had a wing loading of 92.6 kg/m2 (19 lb/ft2) (and even that was considered borderline compared to the earlier Ki 27). To address these concerns, Kawasaki staged a fly off between two Ki 61 prototypes and the Nakajima Ki 43 I, a pre production Nakajima Ki 44 I, a defector flown Lavochkin Gorbunov Goudkov LaGG 3, a Messerschmitt Bf 109E 7, and a captured Curtiss P 40E Warhawk. The Ki 61 proved the fastest of all the aircraft and was inferior only to the Ki 43 in manoeuvrability. The Ki 61 was the last of the fighters powered by the DB 601 or its foreign derivatives, and it was soon overshadowed by fighters with more powerful engines. By the time it first flew in December 1941, one year after the Macchi C.202's first flight and three years after the first Bf 109E, the engine was already underpowered compared to the new 1,120 kW (1,500 hp) inline or 1,491 kW (2,000 hp) radial engines being developed (and already nearing the mass production stage) to power the next generation of combat aircraft such as the Republic P 47 Thunderbolt. Moreover, the inline Ha 40 engine proved to be an unreliable powerplant, exacerbated in the South Pacific campaign, where high temperatures caused problems with the fuel pumps. The DB 601 engine required precise and sophisticated manufacturing; the Ha 40 was lighter by roughly 30 kg (70 lb) and required even higher manufacturing standards. Reaching these standards proved difficult for Japanese manufacturers, an issue further complicated by the variable quality of materials, fuel, and the lubricants needed to run a sensitive, high performance engine. The Japanese equivalent of the more powerful DB 605 engine was the Kawasaki Ha 140, which was fitted onto the Type 3 to produce the Ki 61 II high altitude interceptor. Compared to the Ki 61 I, the Ki 61 II had 10% greater wing area, used more armour and was powered by the Kawasaki Ha 140 engine generating 1,120 kW (1,500 hp). After overcoming initial fuselage and wing stability problems, the new interceptor reverted to the original wing and was put into service as the Ki 61 II KAI. However, the Ha 140 engine had severe reliability problems that were never fully resolved, and around half of the first batch of engines delivered were returned to the factory to be re built. A US bombing raid on 19 January 1945 destroyed the engine factory in Akashi, Hyōgo, and 275 Ki 61 II KAI airframes without engines were converted to use the Mitsubishi Ha 112 II radial engine, resulting in the Ki 100. While the Ha 112 solved the problems encountered with the Ha 140, the new engine still had a major weakness: a lack of power at altitude, which diminished its ability to intercept high flying B 29 Superfortresses relative to the Ki 61 II. During testing, the Hien proved capable, but several shortcomings were subsequently revealed in operational service, namely the armor protection that was insufficient against larger guns and a sub standard engine that eventually led to a new engine being considered. Operational history

The Ki 61 looked so different from the usual radial engined Japanese fighters that the Allies at first believed it to be of German or Italian origin, possibly a license built Messerschmitt Bf 109. The first Ki 61 seen by Allied aircrew had been misidentified as a Bf 109 by USAAF Capt. C. Ross Greening during the Doolittle Raid. In early reports, when it was thought to have been a German fighter, the Ki 61 had been code named "Mike". The new Ki 61 Hien fighters entered service with a special training unit, the 23rd Chutai, and entered combat for the first time in early 1943, during the New Guinea campaign. The first Sentai (Air Group/Wing) fully equipped with the Hien was the 68th in Wewak, New Guinea, The finicky Ha 40 engine could not be overhauled in the theatre, instead they had to be shipped to the nearest service depot in Halmahera, in eastern Indonesia. By the end of the campaign, nearly 2,000 Japanese aircraft had been lost in air attacks from up to 200 Allied aircraft at a time, around half of which were Consolidated B 24 Liberators and North American B 25 Mitchells armed with fragmentation bombs. The Ki 61 carried a great deal of fuel, but due to having self sealing fuel tanks it was not considered readily flammable, as many other Japanese aircraft were. Owing to the additional weight, the Ki 61's performance and agility suffered when its armament was increased, but it still remained capable with a 580 km/h (313 kn) maximum speed. The cannon armament was needed to counter the Allied bombers, which proved to be difficult to shoot down with only 12.7 mm (.50 in) machine guns. The empty and maximum weights for the Ki 61 prototype (2 × 12.7 mm/0.50 in + 2 × 7.7 mm/0.303 in) were 2,238 kg (4,934 lb) and 2,950 kg (6,504 lb), respectively; for the Ki 61 I basic (4 × 12.7 mm/.50 in) 3,130 kg (6,900 lb); and for the Ki 61 KAI (2 × 12.7 mm/0.50 in + 2 × 20 mm), 2,630 kg (5,798 lb) and 3,470 kg (6,750 lb). Ki 61 Special Attack Unit

The tactic of using aircraft to ram American Boeing B 29 Superfortresses was first recorded in late August 1944, when B 29s from Chinese airfields attempted to bomb the steel factories at Yawata. Sergeant Shigeo Nobe of the 4th Sentai intentionally flew his Kawasaki Ki 45 into a B 29; debris from the explosion severely damaged another B 29, which also went down. Other attacks of this nature followed, as a result of which individual pilots determined it was a practicable way of destroying B 29s. On 7 November 1944, the officer commanding the 10th Hiko Shidan (Air division) made ramming attacks a matter of policy by forming ramming attack flights specifically to oppose the B 29s at high altitude. The aircraft were stripped of their fuselage armament and protective systems in order to attain the required altitudes. Although the term "kamikaze" is often used to refer to the pilots undertaking these attacks, the word was not used by the Japanese military. The units assigned to the 10th Hiko Shidan included the 244th Hiko Sentai (Fighter group), then commanded by Captain Takashi Fujita, who organised a ramming flight called "Hagakure Tai" ("Special Attack Unit"), which was composed out of volunteers from the three Chutai (squadrons) of the 244th: the 1st Chutai "Soyokaze", 2nd Chutai "Toppu", and the 3rd Chutai known as "Mikazuki". First Lieutenant Toru Shinomiya was selected to lead the Hagakure Tai. On 3 December 1944, Shinomiya – along with Sergeant Masao Itagaki and Sergeant Matsumi Nakano – intercepted a B 29 raid; Shinomaya rammed one B 29, but was able to land his damaged Ki 61, which had lost most of the port outer wing, back at base. After attacking another B 29 Itagaki had to parachute from his damaged fighter, while Nakano rammed and damaged Long Distance of the 498th BG and crash landed his stripped down Ki 61 in a field. Shinomaya's damaged Ki 61 was later displayed inside Tokyo's Matsuya department store while Nakano's Ki 61 was displayed outside, alongside of a life size cut away drawing of the forward fuselage of a B 29. These three pilots were the first recipients of the Bukosho, Japan's equivalent to the Victoria Cross or Medal of Honor, which had been inaugurated on 7 December 1944 as an Imperial Edict by Emperor Hirohito (there are 89 known recipients, most of whom fought and scored against B 29s). The existence of the ramming unit had been kept confidential until then, but it was officially disclosed in the combat results announcement and officially named "Shinten Seiku Tai" ("Body Attack Detachment") by the Defense GHQ. On 27 January 1945, Itakagi survived another ramming attack on a B 29, again parachuting to safety, and received a second Bukosho; he survived the war as only one of two known double Bukosho recipients. Sergeant Shigeru Kuroishikawa was another distinguished member of the unit. Despite their successful attacks, these pilots gained no reprieve, and were obliged to continue these deadly and dangerous ramming tactics until they were killed, or else wounded so badly that they could no longer fly. They were regarded as doomed men and were celebrated among the ranks of those who were going to certain death as Tokkotai (kamikaze) pilots. Some other Ki 61 pilots also achieved renown, among them Major Teruhiko Kobayashi of the 244th Sentai, who was credited by some with a dozen victories mostly due to conventional attacks against B 29s. Variants
Note: Ko, Otsu, Hei and Tei are the Japanese equivalents to a, b, c, d. Kai ('modified' or 'improved') was also used for some models of the Ki 61. Ki 61 Hien
Ki 61 Prototypes: 12 built
Ki 61 I Ko First production version: fully retractable tailwheel, two 7.7 mm (0.303 in) Type 89 machine guns in the wings and two synchronized 12.7 mm (0.50 in) Ho 103 machine guns in the forward decking. Capable of carrying one 151 L (40 gal) drop tank or a light bomb. Year Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Annual 1942 1 3 5 10 15 34 1943 22 32 31 37 44 40 53 60 70 87 104 130 710 1944 150 156 145 142 118 236 254 198 164 174 101 53 1,891 1945 19 19 Total 2,654

Not included:

Pre production started with the first prototype completed in July 1941, and with further eleven builds in early 1942. +Ki 61 II Production: Kawasaki Kokuki K. K

Not included:

Pre production started with eight prototypes completed during Aug. 1943 to Jan. 1944. Most aircraft were destroyed in military conflicts between the Netherlands and the newly proclaimed Republic of Indonesia during the Indonesian National Revolution of 1945–1949. Sentai Established Aircraft type(s) Area of operations Disbanded Notes 17th 10 February 1944 at Kagamigahara, Gifu Prefecture Ki 61, Ki 100 Philippines, Formosa, Japan End of war One of Kawasaki's main factories was located at Kagamigahara which, in 1944 was not yet a city. 18th 10 February 1944 at Chōfu from the 244th Sentai Ki 61, Ki 100 Philippines, Japan End of War Lt Mitsuo Oyake won Bukosho for shooting down three B 29s (one by ramming) 7 April 1945 and damaging three others. 19th 10 February 1944 at Akeno Fighter School Ki 61 Indonesia, Philippines, Formosa, Okinawa End of War (Formosa) 23rd 11 October 1944 at Inba, Chiba Prefecture Ki 43, Ki 44, Ki 61 Iwo Jima, Formosa, Japan End of war (Inba) 26th Late 1944 Ki 51, Ki 43, Ki 61 Formosa End of war (Formosa) 28th June 1939 in Manchuria Ki 46, Ki 61, Ki 102 Manchuria, Japan July 1945 31st July 1938 in China Ki 10, Ki 43, Ki 61Manchuria, Philippines 30 May 1945 at Singapore 33rd Summer 1937 in China Ki 10, Ki 27, Ki 43, Ki 61 New Guinea, Manchuria (Manchoukuo), East Indies End of war, Medan, Dutch East Indies (currently Indonesia) 53rd 23 March 1944 at Tokorozawa, Saitama Ki 61, Ki 45 Japan, Eastern Defence Sector flew Ki 61 for a short time in Home Island Defence 55th 30 May 1944 at Taishō, Osaka Prefecture Ki 61 Philippines, Japan End of war at Sana, Nara Prefecture 56th August 1944 at Taishō Osaka Prefecture Ki 61 Japan End of war at Itami, Hyōgo Prefecture Unit claimed 11 B 29s for 30 pilots lost. Warrant Officer Tadao Sumi (five B 29s plus one P 51 Mustang destroyed, four B 29s damaged) Bukosho recipient. 59th 1 July 1938 at Kagamigahara, Gifu Prefecture Ki 10, Ki 27, Ki 43, Ki 61, Ki 100 China, Manchuria (Nomonhan), Indochina, East Indies, New Guinea, Okinawa, Japan End of War at Ashiya, Fukuoka Prefecture 1st Lieutenant Naoyuki Ogata Bukosho recipient. Warrant Officer Kazuo Shimizu flew with unit from February 1942 right through to August 1945; 18 victories, including nine bombers. 65th presumably 1938 1939 Ki 32, Ki 51, Ki 43, Ki 61, Ki 45 Philippines, Formosa, Okinawa, Japan End of war, Metabaru, Saga Unit used Ki 61 from the summer of 1944 68th March 1942 at Harbin, Manchuria Ki 27, Ki 61 Rabaul (New Britain), New Guinea, Halmahera 25 July 1944 First unit to convert to the Ki 61. Unit was destroyed by Allied air forces in New Guinea. Most surviving ground and aircrew were used as infantry, with few survivors. A Ki 61 1 Otsu, manufacturer's No. 640 is one of the best preserved aircraft wrecks in New Guinea. Captain Shogo Takeuchi transferred from 64th Sentai, April 1942. KIA 15 December 1943 30+ victories. Sgt. Susumu Kaijinami officially credited with eight victories plus 16 unofficially. 78th 31 March 1942 in ChinaKi 27, Ki 61Manchuria, Rabaul, New Guinea 25 July 1944 Second unit to convert to the Ki 61. Unit was destroyed by Allied air forces in New Guinea. Most surviving ground and aircrew were used as infantry, with few survivors. 105th August 1944, Taichung, Formosa Ki 61Okinawa, Formosa End of war (Formosa) 244th April 1942, reorganised from 144th SentaiKi 27, Ki 61, Ki 100Okinawa, Formosa End of war (Yokaichi, Shiga Prefecture) Nine Bukosho recipients. Major Teruhiko Kobayashi JAAF's youngest Sentai commander. Also had an air to air B 29 ramming unit. Sentai claimed 73 B 29s shot down plus 92 damaged. Most famous of the Home Defence Sentais. Captain Nagao Shirai considered the ranking ace of 244 Sentai and possibly leading B 29 "killer" of JAAF (11 B 29s) plus two Grumman F6F Hellcats destroyed, six other aircraft damaged using Ki 61 and Ki 100. Captain Chuichi Ichikawa nine B 29s plus one F6F destroyed, six B 29s damaged. Major Teruhiko Kobayashi, three B 29s plus two F6Fs destroyed. Training units 23rd Dokuritsu Dai Shijugo (Independent Chutai) Chōfu, 1941Ki 61Japan Became basis of 23rd Sentai Evaluation and conversion unit for Ki 61. Akeno Kyodo Hikoshidan (Akeno Flight School) Akeno, Mie Prefecture, 1935Ki 10, Ki 27, Ki 43, Ki 44, Ki 45, Ki 61, Ki 84, Ki 100Japan End of war Main flight training school for Army fighter pilots. Many of the instructors participated in missions in defence of Japan 1944–1945. Akeno Airbase still in operational use. 37th Kyoiku Hikōtai (Flight Training Company) Matsuyama airfield, Formosa, 1943 Ki 43, Ki 44, Ki 45, Ki 61, Ki 84 Formosa End of war Flight training school for Army fighter pilots. Many of the instructors participated in missions in defence of Japan 1944 1945

WWII Japanese Fighter Aircraft

type = Fighter aircraft
manufacturer = Kawasaki Kōkūki Kōgyō K. K.
designer =
first flight = December 1941
introduced = 1942
retired = 1945
status =
primary user = Imperial Japanese Army Air Service
more users = Chinese Nationalist Air Force, Indonesian Air Force, People's Liberation Army Air Force
produced =
number built = 3,078 Allied intelligence initially believed Ki 61s were Messerschmitt Bf 109s and later an Italian Macchi C.202, which led to the Allied reporting name of "Tony", assigned by the United States War Department. The design originated as a variant of the Kawasaki Ki 60, which never entered production. The Ki 61 became the only mass produced Japanese fighter of the war to use a liquid cooled inverted V engine. Over 3,000 Ki 61s were produced. Initial prototypes saw action over Yokohama during the Doolittle Raid on 18 April 1942, and continued to fly combat missions throughout the war. Design and development
The Ki 61 was designed by Takeo Doi and his deputy Shin Owada in response to a late 1939 tender by the Koku Hombu for two fighters, each to be built around the Daimler Benz DB 601Aa. Production aircraft would use a Kawasaki licensed DB 601, known as the Ha 40, which was to be manufactured at its Akashi plant. The Ki 60 was to be a heavily armed specialised interceptor, with a high wing loading; the Ki 61 was to be a more lightly loaded and armed general purpose fighter, intended to be used mainly in an offensive, air superiority role at low to medium altitudes. Both single seat, single engine fighters used the same basic construction: all metal alloys with semi monocoque fuselages and three spar wings, with alloy framed, fabric covered ailerons, elevators and rudders. Priority was given to the Ki 60, which first flew in April 1941, while design work on the Ki 61 did not begin until December 1940. Although the Ki 61 was broadly similar to the Ki 60, it featured several refinements exploiting lessons learned from the disappointing flight characteristics of the earlier design. The all metal, semi monocoque fuselage was basically oval in cross section, changing to a tapered, semi triangular oval behind the cockpit canopy, with a maximum depth of 1.35 m (4 ft 5 in). An unusual feature of the Ki 61 was that the engine bearers were constructed as an integral part of the forward fuselage, with the cowling side panels being fixed. For servicing or replacement, only the top and bottom cowling panels could be removed. A tapered, rectangular supercharger air intake was located on the port side cowling. Behind the engine bulkhead were the ammunition boxes feeding a pair of synchronized 12.7 mm (.50 in) Ho 103 machine guns which were set in a "staggered" configuration (the port weapon slightly further forward than that to starboard) in a bay just above and behind the engine. The breeches partly projected into the cockpit, above the instrument panel. The Ho 103 was a light weapon for its caliber (around 23 kg/51 lb) and fired a light shell, but this was compensated for by its rapid rate of fire. The ammunition capacity was limited, having only around 250 rounds for each weapon. A self sealing fuel tank with a capacity of 165 L (44 US gal) was located behind the pilot's seat. The windshield was armored and there was a 13 mm (.51 in) armor plate behind the pilot. The radiator and oil cooler for the liquid cooled engine were in a ventral location below the fuselage and wing trailing edge, covered by a rectangular section fairing with a large, adjustable exit flap. Although test pilots were enthusiastic about its self sealing fuel tanks, upgraded armament, and good dive performance, the wing loading of 146.3 kg/m2 (30 lb/ft2) at an all up weight of 2,950 kg (6,500 lb) was viewed with scepticism by many of the senior officers of the Koku Hombu, who still believed in the light, highly manoeuvrable, lightly armed fighter epitomised by the then new Nakajima Ki 43 I Hei which had a wing loading of 92.6 kg/m2 (19 lb/ft2) (and even that was considered borderline compared to the earlier Ki 27). To address these concerns, Kawasaki staged a fly off between two Ki 61 prototypes and the Nakajima Ki 43 I, a pre production Nakajima Ki 44 I, a defector flown Lavochkin Gorbunov Goudkov LaGG 3, a Messerschmitt Bf 109E 7, and a captured Curtiss P 40E Warhawk. The Ki 61 proved the fastest of all the aircraft and was inferior only to the Ki 43 in manoeuvrability. The Ki 61 was the last of the fighters powered by the DB 601 or its foreign derivatives, and it was soon overshadowed by fighters with more powerful engines. By the time it first flew in December 1941, one year after the Macchi C.202's first flight and three years after the first Bf 109E, the engine was already underpowered compared to the new 1,120 kW (1,500 hp) inline or 1,491 kW (2,000 hp) radial engines being developed (and already nearing the mass production stage) to power the next generation of combat aircraft such as the Republic P 47 Thunderbolt. Moreover, the inline Ha 40 engine proved to be an unreliable powerplant, exacerbated in the South Pacific campaign, where high temperatures caused problems with the fuel pumps. The DB 601 engine required precise and sophisticated manufacturing; the Ha 40 was lighter by roughly 30 kg (70 lb) and required even higher manufacturing standards. Reaching these standards proved difficult for Japanese manufacturers, an issue further complicated by the variable quality of materials, fuel, and the lubricants needed to run a sensitive, high performance engine. The Japanese equivalent of the more powerful DB 605 engine was the Kawasaki Ha 140, which was fitted onto the Type 3 to produce the Ki 61 II high altitude interceptor. Compared to the Ki 61 I, the Ki 61 II had 10% greater wing area, used more armour and was powered by the Kawasaki Ha 140 engine generating 1,120 kW (1,500 hp). After overcoming initial fuselage and wing stability problems, the new interceptor reverted to the original wing and was put into service as the Ki 61 II KAI. However, the Ha 140 engine had severe reliability problems that were never fully resolved, and around half of the first batch of engines delivered were returned to the factory to be re built. A US bombing raid on 19 January 1945 destroyed the engine factory in Akashi, Hyōgo, and 275 Ki 61 II KAI airframes without engines were converted to use the Mitsubishi Ha 112 II radial engine, resulting in the Ki 100. While the Ha 112 solved the problems encountered with the Ha 140, the new engine still had a major weakness: a lack of power at altitude, which diminished its ability to intercept high flying B 29 Superfortresses relative to the Ki 61 II. During testing, the Hien proved capable, but several shortcomings were subsequently revealed in operational service, namely the armor protection that was insufficient against larger guns and a sub standard engine that eventually led to a new engine being considered. Operational history

The Ki 61 looked so different from the usual radial engined Japanese fighters that the Allies at first believed it to be of German or Italian origin, possibly a license built Messerschmitt Bf 109. The first Ki 61 seen by Allied aircrew had been misidentified as a Bf 109 by USAAF Capt. C. Ross Greening during the Doolittle Raid. In early reports, when it was thought to have been a German fighter, the Ki 61 had been code named "Mike". The new Ki 61 Hien fighters entered service with a special training unit, the 23rd Chutai, and entered combat for the first time in early 1943, during the New Guinea campaign. The first Sentai (Air Group/Wing) fully equipped with the Hien was the 68th in Wewak, New Guinea, The finicky Ha 40 engine could not be overhauled in the theatre, instead they had to be shipped to the nearest service depot in Halmahera, in eastern Indonesia. By the end of the campaign, nearly 2,000 Japanese aircraft had been lost in air attacks from up to 200 Allied aircraft at a time, around half of which were Consolidated B 24 Liberators and North American B 25 Mitchells armed with fragmentation bombs. The Ki 61 carried a great deal of fuel, but due to having self sealing fuel tanks it was not considered readily flammable, as many other Japanese aircraft were. Owing to the additional weight, the Ki 61's performance and agility suffered when its armament was increased, but it still remained capable with a 580 km/h (313 kn) maximum speed. The cannon armament was needed to counter the Allied bombers, which proved to be difficult to shoot down with only 12.7 mm (.50 in) machine guns. The empty and maximum weights for the Ki 61 prototype (2 × 12.7 mm/0.50 in + 2 × 7.7 mm/0.303 in) were 2,238 kg (4,934 lb) and 2,950 kg (6,504 lb), respectively; for the Ki 61 I basic (4 × 12.7 mm/.50 in) 3,130 kg (6,900 lb); and for the Ki 61 KAI (2 × 12.7 mm/0.50 in + 2 × 20 mm), 2,630 kg (5,798 lb) and 3,470 kg (6,750 lb). Ki 61 Special Attack Unit

The tactic of using aircraft to ram American Boeing B 29 Superfortresses was first recorded in late August 1944, when B 29s from Chinese airfields attempted to bomb the steel factories at Yawata. Sergeant Shigeo Nobe of the 4th Sentai intentionally flew his Kawasaki Ki 45 into a B 29; debris from the explosion severely damaged another B 29, which also went down. Other attacks of this nature followed, as a result of which individual pilots determined it was a practicable way of destroying B 29s. On 7 November 1944, the officer commanding the 10th Hiko Shidan (Air division) made ramming attacks a matter of policy by forming ramming attack flights specifically to oppose the B 29s at high altitude. The aircraft were stripped of their fuselage armament and protective systems in order to attain the required altitudes. Although the term "kamikaze" is often used to refer to the pilots undertaking these attacks, the word was not used by the Japanese military. The units assigned to the 10th Hiko Shidan included the 244th Hiko Sentai (Fighter group), then commanded by Captain Takashi Fujita, who organised a ramming flight called "Hagakure Tai" ("Special Attack Unit"), which was composed out of volunteers from the three Chutai (squadrons) of the 244th: the 1st Chutai "Soyokaze", 2nd Chutai "Toppu", and the 3rd Chutai known as "Mikazuki". First Lieutenant Toru Shinomiya was selected to lead the Hagakure Tai. On 3 December 1944, Shinomiya – along with Sergeant Masao Itagaki and Sergeant Matsumi Nakano – intercepted a B 29 raid; Shinomaya rammed one B 29, but was able to land his damaged Ki 61, which had lost most of the port outer wing, back at base. After attacking another B 29 Itagaki had to parachute from his damaged fighter, while Nakano rammed and damaged Long Distance of the 498th BG and crash landed his stripped down Ki 61 in a field. Shinomaya's damaged Ki 61 was later displayed inside Tokyo's Matsuya department store while Nakano's Ki 61 was displayed outside, alongside of a life size cut away drawing of the forward fuselage of a B 29. These three pilots were the first recipients of the Bukosho, Japan's equivalent to the Victoria Cross or Medal of Honor, which had been inaugurated on 7 December 1944 as an Imperial Edict by Emperor Hirohito (there are 89 known recipients, most of whom fought and scored against B 29s). The existence of the ramming unit had been kept confidential until then, but it was officially disclosed in the combat results announcement and officially named "Shinten Seiku Tai" ("Body Attack Detachment") by the Defense GHQ. On 27 January 1945, Itakagi survived another ramming attack on a B 29, again parachuting to safety, and received a second Bukosho; he survived the war as only one of two known double Bukosho recipients. Sergeant Shigeru Kuroishikawa was another distinguished member of the unit. Despite their successful attacks, these pilots gained no reprieve, and were obliged to continue these deadly and dangerous ramming tactics until they were killed, or else wounded so badly that they could no longer fly. They were regarded as doomed men and were celebrated among the ranks of those who were going to certain death as Tokkotai (kamikaze) pilots. Some other Ki 61 pilots also achieved renown, among them Major Teruhiko Kobayashi of the 244th Sentai, who was credited by some with a dozen victories mostly due to conventional attacks against B 29s. Variants
Note: Ko, Otsu, Hei and Tei are the Japanese equivalents to a, b, c, d. Kai ('modified' or 'improved') was also used for some models of the Ki 61. Ki 61 Hien
Ki 61 Prototypes: 12 built
Ki 61 I Ko First production version: fully retractable tailwheel, two 7.7 mm (0.303 in) Type 89 machine guns in the wings and two synchronized 12.7 mm (0.50 in) Ho 103 machine guns in the forward decking. Capable of carrying one 151 L (40 gal) drop tank or a light bomb. Year Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Annual 1942 1 3 5 10 15 34 1943 22 32 31 37 44 40 53 60 70 87 104 130 710 1944 150 156 145 142 118 236 254 198 164 174 101 53 1,891 1945 19 19 Total 2,654

Not included:

Pre production started with the first prototype completed in July 1941, and with further eleven builds in early 1942. +Ki 61 II Production: Kawasaki Kokuki K. K

Not included:

Pre production started with eight prototypes completed during Aug. 1943 to Jan. 1944. Most aircraft were destroyed in military conflicts between the Netherlands and the newly proclaimed Republic of Indonesia during the Indonesian National Revolution of 1945–1949. Sentai Established Aircraft type(s) Area of operations Disbanded Notes 17th 10 February 1944 at Kagamigahara, Gifu Prefecture Ki 61, Ki 100 Philippines, Formosa, Japan End of war One of Kawasaki's main factories was located at Kagamigahara which, in 1944 was not yet a city. 18th 10 February 1944 at Chōfu from the 244th Sentai Ki 61, Ki 100 Philippines, Japan End of War Lt Mitsuo Oyake won Bukosho for shooting down three B 29s (one by ramming) 7 April 1945 and damaging three others. 19th 10 February 1944 at Akeno Fighter School Ki 61 Indonesia, Philippines, Formosa, Okinawa End of War (Formosa) 23rd 11 October 1944 at Inba, Chiba Prefecture Ki 43, Ki 44, Ki 61 Iwo Jima, Formosa, Japan End of war (Inba) 26th Late 1944 Ki 51, Ki 43, Ki 61 Formosa End of war (Formosa) 28th June 1939 in Manchuria Ki 46, Ki 61, Ki 102 Manchuria, Japan July 1945 31st July 1938 in China Ki 10, Ki 43, Ki 61Manchuria, Philippines 30 May 1945 at Singapore 33rd Summer 1937 in China Ki 10, Ki 27, Ki 43, Ki 61 New Guinea, Manchuria (Manchoukuo), East Indies End of war, Medan, Dutch East Indies (currently Indonesia) 53rd 23 March 1944 at Tokorozawa, Saitama Ki 61, Ki 45 Japan, Eastern Defence Sector flew Ki 61 for a short time in Home Island Defence 55th 30 May 1944 at Taishō, Osaka Prefecture Ki 61 Philippines, Japan End of war at Sana, Nara Prefecture 56th August 1944 at Taishō Osaka Prefecture Ki 61 Japan End of war at Itami, Hyōgo Prefecture Unit claimed 11 B 29s for 30 pilots lost. Warrant Officer Tadao Sumi (five B 29s plus one P 51 Mustang destroyed, four B 29s damaged) Bukosho recipient. 59th 1 July 1938 at Kagamigahara, Gifu Prefecture Ki 10, Ki 27, Ki 43, Ki 61, Ki 100 China, Manchuria (Nomonhan), Indochina, East Indies, New Guinea, Okinawa, Japan End of War at Ashiya, Fukuoka Prefecture 1st Lieutenant Naoyuki Ogata Bukosho recipient. Warrant Officer Kazuo Shimizu flew with unit from February 1942 right through to August 1945; 18 victories, including nine bombers. 65th presumably 1938 1939 Ki 32, Ki 51, Ki 43, Ki 61, Ki 45 Philippines, Formosa, Okinawa, Japan End of war, Metabaru, Saga Unit used Ki 61 from the summer of 1944 68th March 1942 at Harbin, Manchuria Ki 27, Ki 61 Rabaul (New Britain), New Guinea, Halmahera 25 July 1944 First unit to convert to the Ki 61. Unit was destroyed by Allied air forces in New Guinea. Most surviving ground and aircrew were used as infantry, with few survivors. A Ki 61 1 Otsu, manufacturer's No. 640 is one of the best preserved aircraft wrecks in New Guinea. Captain Shogo Takeuchi transferred from 64th Sentai, April 1942. KIA 15 December 1943 30+ victories. Sgt. Susumu Kaijinami officially credited with eight victories plus 16 unofficially. 78th 31 March 1942 in ChinaKi 27, Ki 61Manchuria, Rabaul, New Guinea 25 July 1944 Second unit to convert to the Ki 61. Unit was destroyed by Allied air forces in New Guinea. Most surviving ground and aircrew were used as infantry, with few survivors. 105th August 1944, Taichung, Formosa Ki 61Okinawa, Formosa End of war (Formosa) 244th April 1942, reorganised from 144th SentaiKi 27, Ki 61, Ki 100Okinawa, Formosa End of war (Yokaichi, Shiga Prefecture) Nine Bukosho recipients. Major Teruhiko Kobayashi JAAF's youngest Sentai commander. Also had an air to air B 29 ramming unit. Sentai claimed 73 B 29s shot down plus 92 damaged. Most famous of the Home Defence Sentais. Captain Nagao Shirai considered the ranking ace of 244 Sentai and possibly leading B 29 "killer" of JAAF (11 B 29s) plus two Grumman F6F Hellcats destroyed, six other aircraft damaged using Ki 61 and Ki 100. Captain Chuichi Ichikawa nine B 29s plus one F6F destroyed, six B 29s damaged. Major Teruhiko Kobayashi, three B 29s plus two F6Fs destroyed. Training units 23rd Dokuritsu Dai Shijugo (Independent Chutai) Chōfu, 1941Ki 61Japan Became basis of 23rd Sentai Evaluation and conversion unit for Ki 61. Akeno Kyodo Hikoshidan (Akeno Flight School) Akeno, Mie Prefecture, 1935Ki 10, Ki 27, Ki 43, Ki 44, Ki 45, Ki 61, Ki 84, Ki 100Japan End of war Main flight training school for Army fighter pilots. Many of the instructors participated in missions in defence of Japan 1944–1945. Akeno Airbase still in operational use. 37th Kyoiku Hikōtai (Flight Training Company) Matsuyama airfield, Formosa, 1943 Ki 43, Ki 44, Ki 45, Ki 61, Ki 84 Formosa End of war Flight training school for Army fighter pilots. Many of the instructors participated in missions in defence of Japan 1944 1945

299 – Ki 61 Ia under restoration to static display at Ardmore, Auckland, New Zealand by AvSpecs. To be displayed at Papua New Guinea National Museum and Art Gallery once completed. 379 – Ki 61 I in storage at the Fantasy of Flight in Polk City, Florida. 640 – Ki 61 I under restoration to airworthy condition at Ardmore, Auckland, New Zealand by AvSpecs. It will become part of the Military Aviation Museum collection in Virginia Beach, Virginia. 6117 – Ki 61 II Kai on static display at the Kakamigahara Air and Space Museum in Kakamigahara, Gifu. Previously on display at the Chiran Peace Museum for Kamikaze Pilots in Chiran, Kagoshima; it was removed from the museum in September 2015 and restored by Kawasaki Heavy Industries from 2015 to 2016.