Mitsubishi Ki-109

Mitsubishi Ki-109

Mitsubishi Ki-109

The designation Mitsubishi Ki-109 was used for two different attempts to produce an interceptor based on Ki-67 heavy bomber that would be capable of shooting down the new B-29 Superfortress.

The first design, suggested in November 1943, was for a 'Killer-Hunter' team of two aircraft. The Ki-109a would have been the killer, armed with two obliquely mounted 37mm Ho-203 cannon, while the Ki-109b would have been the hunter, equipped with radar and a nose mounted 40cm searchlight.

The second design was proposed by Major Hideo Sakamoto, the officer in charge of the Ki-67 evaluation programme. He suggested mounting an Army 75mm Type 88 anti-aircraft cannon in the nose of the Ki-67. This would reduce the speed and manoeuvrability of the aircraft, but allow it to operate outside the range of the B-29's guns, and was produced in the belief that the American bombers would be forced to operate without fighter cover.

This second design was approved on 20 February 1944. The prototype Ki-109 retained the defensive guns of the Ki-67, but with a new nose and stronger fuselage. From the third aircraft the dorsal turret and lateral machine gun positions were removed. The prototype was completed in August 1944, two months after the first B-29s appeared over Japan, and production began later in the same year. Twenty two aircraft were produced using the Ha-104 engine as the Ki-109-I. They were to be followed by the Ki-109-II, using the 1,900hp turbo-supercharged Ha-104ru engine, but this version never entered production.

The 107th Heavy Fighter Regiment was formed in November 1944, and received its aircraft in 1945. The Ki-109 failed to live up to expectations. The production Ki-109-I lacked the speed and rate of climb to catch the high flying B-29s on their early daylight raids, and despite a number of attempted interceptions never actually made contact with a B-29 formation. Once the Americans switched to low level night-time raids the Ki-109, which lacked radar, became completely useless, and the 107th Heavy Fighter Regiment was disbanded on 30 July 1945.

Engine: Two x Mitsubishi Ha-104
Power: 1,900hp
Crew: 2
Wing span: 73ft 9.75in
Length: 58ft 10.75in
Height: 19ft 1in
Empty Weight: 16,367lb
Maximum take-off weight: 23,810lb
Max Speed: 342mph
Service Ceiling: 31,070ft
Climb rate: 1,467ft/minute
Range: 1,367 miles
Armament: One 75mm cannon and one 12.7mm machine gun in tail turret
Bomb-load: none

Mitsubishi Ki-109

Derived from the Ki-67 Hiryu bomber as a heavy interceptor, the Ki-109 was originally conceived in two versions: the Ki-109-ko mounting two obliquely-firing 37mm cannon and the Ki-109-otsu equipped with radar and a 40cm searchlight. The intention was that the two versions of the aircraft would work as a team. Soon thereafter the Ki-109 project was redefined as a bomber interceptor mounting a 75mm Type 88 cannon with which it could attack its quarry while remaining beyond the range of opposing defensive armament. Converted from a Ki-67 airframe and retaining the dorsal, lateral and tail gun positions of the bomber, and the Mitsubishi Ha-104 engines each rated at 1900hp for take-off, the first Ki-109 prototype was completed in August 1944. The second prototype was powered by Ha-104ru engines with Ru-3 turbo-superchargers, and it was intended that these would be installed in the final 22 aircraft of an initial batch of 42 Ki-109s. The first series Ki-109 dispensed with the dorsal and lateral gun positions, retaining only the tail position which mounted a single 12.7mm machine gun. Primary armament was the single 75mm cannon with 15 shells individually loaded by the co-pilot. In the event, production difficulties with the Ru-3 turbo-supercharger prevented its application to any series Ki-109s, and only 20 production aircraft were completed, these having standard Ha-104 engines.

Looking to find a 1 /72 model of this plane to complete my collection. thanks D

Mitsubishi F-2

The Mitsubishi F-2 fighter was initially intended as a wholly indigenous Japanese multirole fighter design to replace the aging fleet of Mitsubishi F-1s. With design work already underway during the 1980s under the FS-X program designation, the United States government moved in with enough political and economic pressure to force Japan into abandoning its local fighter plans in favor of continued support for American-originated military equipment. The Japan indigenous initiative, therefore, ended in 1987 and the program focused on procurement of the Lockheed F-16C "Fighting Falcon" multirole platform (Block 40). The aircraft would be modified to suit Japanese military requirements headed by Mitsubishi Heavy Industries with Lockheed remaining the primary US contributor. General Electric would provide the necessary turbofan engines. The program produced four modified F-16Cs in the early going and these served as prototypes. First flight was recorded on October 7th, 1995 while, in December, the aircraft was formally designated "F-2". Adopted in 2000, the F-2 continues to serve the Japan Air Self-Defense Force (JASDF) in the air defense, ground attack and maritime strike roles. With ongoing disputes against China and general volatility in the region, the F-2 plays an increasingly important role in Japanese air operations for the island nation (January 2014).

Despite its obvious appearance to the America fighter, the Mitsubishi F-2 incorporates enough new features and local technology to consider it a highly modified Japanese variant of the F-16. The F-2, at its core, is a single-seat, single-engine mount powered by the successful General Electric GE F100-series turbofan with reheat (afterburner). The fuselage, though mimicking the American F-16C in general contour and shape, has evolved to become some 25% larger than the original with more advanced composites introduced to its construction. The fuselage has been lengthened and a three-piece framed cockpit selected over the large -area glass version on the F-16. The tail unit has been given an increase in surface area while the intake is of a larger dimension. Due to restrictions imposed by the American State Department on export of fly-by-wire control software, Japanese engineers have developed a local solution. The nose assembly, too, houses a Mitsubishi-brand Active Electronically Scanned Array (AESA) radar while the cockpit retains Head-Up Display (HUD), color Multi-Function Displays (MFDs) and Hands-on-Throttle-and-Stick (HOTAS) control arrangement.

The F-2 exhibits a length of 51 feet with a wingspan of 36.5 feet and height of 15.5 feet. Empty weight is listed at 21,000lb with a maximum take-off weight of 48,500lb. The GE F110-GE-129 engine produces 17,000lb of dry thrust and 29,500lb of thrust with afterburner engaged. Performance values include a maximum speed of Mach 2, a range of 520 miles and service ceiling of 59,000 feet. A drogue parachute assists in providing short airfield landings.

Standard armament of the F-2 includes an internal 20mm JM61A1 cannon for close-in combat. Optional armament is all externally held across five hardpoints (one underfuselage and four underwing) with ordnance totaling 17,830lbs. The armament suite includes a mix of air-to-air and air-to-surface weaponry. As in the American F-16C, the F-2's wingtips are reserved for AIM-9 Sidewinder short-range air-to-air missiles (or the local Mitsubishi AAM-3 missile). Other air-to-air options include the American AIM-7 Sparrow or local Mitsubishi AAM-4 missile. For ground attack and maritime strike, the F-2 is cleared to carry ASM-1 and ASM-2 anti-ship missiles, anti-radiation missiles, precision-guided munitions, and conventional drop ordnance. The fuselage and inboard underwing hardpoints are further plumbed for external fuel tanks which improve operational ranges of the fleet.

Originally, the Japanese government commissioned for 140 aircraft to emerge from the FS-X program. However, budgetary constraints soon limited this to less than 100 and this has since become 94 production-quality airframes along with the four early prototypes. The aircraft then saw extensive delays with tail assemblies manufactured by Lockheed Martin and developmental problems arising with the new composite wings. This led to the series not formally fielded until 2000 (1999 was the target year) by which time they were quick to replace the outgoing F-1s in the Japanese inventory. Production spanned from 1995 into 2011 and has since completed. Early-batch examples cost the Japanese Defence Agency $100 million per unit which proved problematic in Japanese politics of the period. Indeed, it would have been cheaper to purchase existing F-16 airframes instead.

In all, four distinct production marks have appeared. Two were XF-2A single-seat prototypes followed by a pair of XF-2B two-seat prototypes. The F-2A became the standard single-seat fighter which is supplemented by the F-2B two-seat trainer featuring twin cockpits and dual-control functionality.

F-2s current serve with Air Defense Command, Air Training Command and Air Development and Test Command. Eighteen F-2s were damaged during the 2011 tsunami.

The Mitsubishi F-2 is roughly comparable to the Chengdu J-10 "Vigorous Dragon" which would become its primary adversary in an all out confrontation with China.

Japanese Aircraft of WWII

Early in the war when Japanese fighter pilots were in control of the skies, the few Boeing B-17 Flying Fortresses available in the Southwest Pacific area were the only Allied aircraft to challenge their superiority effectively. As the war developed in favour of the Allies, the longer-ranging Consolidated B-24 Liberators, better suited to the island-hopping war, replaced the B-17s. But for the Japanese the problem of attempting to destroy high flying, well protected and formidably armed bombers remained the same. The Koku Hombu were also aware of the US development of a still more formidable four-engined bomber, the Boeing B-29 Superfortress, and by 1943 they were feverishly studying every means of defence against this feared enemy aircraft.

In early 1943 the Mitsubishi Ki-67 heavy bomber then undergoing flight trials had proved that despite its size and weight it was fast and remarkably manoeuvrable. Consequently in November 1943, officers of the Rikugun Kokugijutsu Kenkyujo (Army Aerotechnical Research Institute) at Tachikawa suggested that the Ki-67 be used as the basis for a hunter-killer aircraft. The project received the designation Ki-109 and two versions were to be built: the Ki-109a, the killer was to mount in the rear fuselage two obliquely-firing 37 mm (1.46 in) Ho-203 cannon while the Ki-109b, the hunter, was to be equipped with radar and a 400 mm searchlight. However, soon thereafter, the project was re-directed at the instigation of Maj Sakamoto who suggested that a standard 75 mm (2.95 in) Type 88 anti-aircraft cannon be mounted in the nose of a standard Ki-67. It was hoped that with this large cannon the aircraft would be able to fire on the B-29s while staying well out of range of their defensive armament. As the Koku Hombu anticipated that, initially at least, B-29s would have to operated without fighter escort, the project was found sound and feasible and, accordingly, Mitsubishi were instructed in January 1944 to begin designing the aircraft, which retained the Ki-109 designation.

Modification of the Ki-67 to mount a 75 mm (2.95 in) Type 88 (Ho-401) cannon in the nose was entrusted to a team led by Engineer Ozawa and the first prototype was completed in August 1944, two months after the B-29s had made their first bombing raid over Japan. Except for its nose, in the lower part of which was mounted the Type 88 (Ho-401) cannon, the Ki-109 prototype was identical to the Ki-67 and retained the waist gun positions and dorsal and tail turrets of the bomber. Ground and inflight test firings of the heavy gun were affected by Maj Makiura of the Rikugun Kokugijutsu Kenkyujo and was sufficiently successful to warrant the placing of an initial order for 44 aircraft. The first twenty-four were each to be powered by two Mitsubishi Ha-104 radials rated at 1,900 hp for take-off, 1,810 hp at 2,200 m (7,220 ft) and 1,610 hp at 6,00 m (20,015 ft) but subsequent aircraft were to receive a pair of Mitsubishi Ha-104 Ru radials fitted with Ru-3 exhaust-driven turbosuperchargers and rated at 1,900 hp for take-off and 1,810 hp at 7,360 m (24,150 ft) to improve performance at the cruising altitude of the B-29s. These engines were actually tested on the second Ki-109 prototype, but no production aircraft were powered by Ha-104 Ru engines. Another attempt to im prove climbing speed was made when a solid propellent rocket battery was installed in the rear bomb-bay of the first prototype but this scheme was abandoned.

Starting with the third Ki-109, the dorsal turret and lateral blisters were dispensed with and no bomb-bay fitted. Fifteen shells were carried for the 75 mm (2.95 in) Type 88 cannon which was hand-loaded by the co-pilot, and the sole defensive armament consisted of a flexible 12.7 mm (0.5 in) Type 1 machine-gun in the tail turret. The rest of the airframe and the powerplant were identical to those of the Ki-67. Despite the lack of high-altitude performance the Ki-109 was pressed into service with the 107th Sentai but, by the time enough aircraft were on hand, the B-29s had switched to low-altitude night operations.

Unit Allocated
107th Sentai.

Technical Data
Manufacturer: Mitsubishi Jukogyo KK (Mitsubishi Heavy Industries Co Ltd).
Type: Twin-engined heavy interceptor.
Crew (4): Pilot, co-pilot and radio-operator in forward cabin and gunner in rear turret.
Powerplant: Two Army Type 4 (Mitsubishi Ha-104) eighteen-cylinder air-cooled radial engines. driving four-blade constant-speed metal propellers.
Armament: One forward-firing 75 mm (2.95 in) Type 88 cannon and flexible one 12.7 mm (0.5 in) Type 1 machine-gun in the tail turret.
Dimensions: Span 22.5 m (73 ft 9 13/16 in) length 17.95 m ( 58 ft 10 11/16 in) height 5.8 m (19 ft 1 1/32 in) wing area 63.85 sq m (708.801 sq ft).
Weights: Empty 7,424 kg (16,367 lb) loaded 10,800 kg (23,810 lb) wing loading 164 kg/sq m (33.6 lb/sq ft) power loading 2.8 kg/hp (6.3 lb/hp).
Performance: Maximum speed 550 km/h (342 mph) at 6,090 m (19,980 ft) range 2,200 km (1,367 miles).
Production: A total of 22 Ki-109s were built by Mitsubishi Jukogyo KK between August 1944 and March 1945.

Japan’s Ace Producer – 6 Mitsubishi Fighters

As a manufacturer of fighter planes, Mitsubishi made a major contribution to the Japanese war effort during the Second World War.

Built to a Japanese Imperial Navy specification, the A5M first took flight in February 1935. It created an immediate good impression with its impressive top speed. The Navy had asked for a plane that could reach 217mph, and the A5M had a top speed of 280mph.

Based on this performance, it went into full production, and the first A5Ms entered service in 1937.

An A5M from the aircraft carrier Akagi in flight with an external fuel tank (1938 or 1939)

At the time, Japan was heavily engaged in an invasion of China, and improved versions of the A5M become the Navy’s more important fighter in this war. The Chinese had been inflicting heavy losses on Japanese pilots, but within a short time after the arrival of the A5M2a, the Japanese achieved total superiority in the air. The introduction of the A5M2b, developed using experience gained in China, pushed things even further – the Chinese withdrew all air units out of Japanese fighter range.

In response to the Chinese withdrawal, Mitsubishi provided the A5M4, which had even greater range. This allowed Japanese pilots to push the Chinese air units even further back from the fighting zone.


When fighting against America and its allies started in 1941, the A5M was quickly outclassed by modern Allied fighters. It was withdrawn to second-line duties, returning to the front line as a kamikaze plane in the last desperate days of the war.

A6M Zero-Sen

When the Japanese Navy issued a new requirement in 1937 for a fighter with greater maneuverability, speed, range, and weaponry, only Mitsubishi rose to the challenge. They succeeded with style, producing the A6M, the most famous and feared Japanese plane of the Second World War.

A6M2 Zero in flight.Photo Marc Grossman CC BY-SA 3.0

The A6M entered service in 1939 and soon increased Japan’s aerial dominance over China. Word of this powerful new plane reached the Americans, who largely ignored it until the attack on Pearl Harbor in 1941. This proved to be a mistake, as large numbers of A6Ms and their superior design gave Japan the edge in the Pacific throughout 1942, outclassing even the most maneuverable Allied fighters.

A6M2a model11 over China.

In mid-1942, the Allies finally acquired a complete A6M and sent it back to America for testing. This revealed the plane’s weaknesses, including a lack of protection for the fuel tanks and pilot. When new, better armored Allied planes joined the fight in 1943, they quickly turned the tables, devastating units of A6Ms.

An improved engine allowed the A6M8 to better compete with Allied fighters, but by then the war had turned against Japan. The now-underperforming A6M was the first plane used for kamikaze suicide attacks.

A6M5c Zeros preparing to take part in a kamikaze attack

10,938 A6M Zeros were produced in total, making the A6M the most numerous Japanese plane of the war.

J2M Raiden

The J2M represented a change in approach for the Japanese Navy. Previously, they had focused on maneuverability in their fighters. With the J2M, speed and climb were paramount. The reason for this was that the J2M would have a different role from other fighters: intercepting incoming Allied bombers.

Two J2Ms of the 381 Kōkūtai in British Malaya being tested and evaluated by Japanese naval aviators under close supervision of RAF officers from Seletar Airfield in December 1945.

Though designed by the same team as the A6M, the J2M was not as successful. Early versions had problems that prevented them from meeting Navy specifications. Technical issues kept an improved version of the plane out of action until December 1943.

Despite this, the J2M played an important role in air defense over Japan in the final stage of the war.

Over the Philippines, a formation of aircraft led by a captured Japanese Navy interceptor fighter aircraft Mitsubishi J2M Raiden (Thunderbolt, allied code name “Jack”), of the Technical Air Intelligence Unit, South West Pacific Area

Ki-46-III Kai

The original Ki-46 was a reconnaissance plane fitted with photographic equipment.

In the summer of 1943, with the Allies on the offensive, the Japanese Army needed a heavy interceptor to take out incoming bombers and they needed to get it into action as quickly as possible. Attention turned to the Ki-46, with its proven performance and high speed. The Army Aerotechnical Research Institute converted the plane, replacing its photographic equipment with cannons, to create the Ki-46-III.

The surviving Mitsubishi Ki-46-III displayed at RAF Chivenor in 1971.Photo RuthAS CC BY 3.0

200 of these planes were made, with the first going into combat in October 1944. They did not live up to the hopes of the army planners. An unimpressive climb rate hindered interceptions, and their lack of armor made them vulnerable to the gunners of American B-29s. When the Americans switched to night attacks, a lack of radar made the Ki-46-III even less useful.

The Mitsubishi Ki-46 was a WWII Japanese twin-engined reconnaissance plane. During the last days of the war, it was modified as a high altitude interceptor, with two 20 mm cannons in the nose and one 37 mm cannon in an “upwards-and-forwards” position. Photo: Tony Hisgett CC BY 2.0


Another answer to the B-29 raids was the Ki-109. This was another conversion job, turning the Ki-67 heavy bomber into an interceptor.

Originally, planners intended to make two versions of this plane. One would be a hunter, equipped with a searchlight and radar with which to find Allied planes at night. The other would be a killer, equipped with a heavy cannon for taking out targets. This scheme was soon abandoned in favor of a simpler approach: a single, heavily armed daytime interceptor.

Mitsubishi Ki-109

Equipped with a better engine than the Ki-67, the Ki-109 was very maneuverable at lower altitudes, but not at high altitudes. In the end, this did not matter much, because the Americans switched to low altitude nighttime raids for which the Ki-109 was not equipped. Only 22 Ki-109s went into service.

Ki-67 74-148 of the 74th Hikō Sentai. (Matsumoto airfield, Japan, 1945.)

Decades after the heyday of the Mitsubishi planes, Japan began to consider producing home-grown fighters once more. In 1987, under pressure from the United States, the Japanese decided to base their plane on an American design, the General Dynamics F-16.

Mitsubishi F-2 in flight.Photo: Jerry Gunner CC BY-SA 2.0

Built with the help of General Dynamics and then Lockheed Martin, the F-2 incorporated Japanese technology into a broadly American design. The first prototype flew in 1995 and the plane joined the Japanese Air Self-Defense Force in 2000.

The F-2 serves in a range of roles, including air defense and ground attack.

Mitsubishi Ki-109 - History

The Mitsubishi Ki-109, nicknamed &ldquoPeggy&rdquo by allied forces, was a Japanese late war design intended to defend the home islands from high altitude bombing raids, conducted by the USAF. Although its operational service was short-lived, the Ki-109 will receive a second chance at proving what it&rsquos capable of in the upcoming 1.71 update.

In 1943, the decision was made to develop a new heavy fighter/interceptor based on the existing Ki-67 bomber. The new design was part of Japanese efforts to counter strategic high-altitude bombing conducted by heavy US bombers, such as the B-29 Superfortress, on the Japanese home islands. To achieve this, Mitsubishi engineers proposed the installation of the 75mm Type 88 anti-aircraft cannon inside the aircraft&rsquos nose. The project, designated as Ki-109, was approved in early 1944 and the first two prototypes were already completed in late summer of the same year.

However, as initial testing showed that the aircraft was lacking speed due it&rsquos high mass, measures were taken to remove unnecessary equipment in order to save on weight. During this process, the Ki-109 lost most of its defensive turrets and only retained the one located in the tail section. Another attempt to improve the aircraft&rsquos speed was the intended installation of the new, more powerful Ha-104ru engines in the following production batch, however this idea was quickly dropped due to the engine having reliability issues, thus production continued with the standard Ha-104 engines.

In March of 1945, 22 Ki-109s were delivered to the 107th Sentai unit, which was tasked with protecting the strategically important cities of Tokyo and Yokohama from air raids. In July, only a few months before the War came to a close, the 107th Sentai was formally disbanded, leaving behind some Ki-109s to be tested for effectiveness against ships, this also marking the end of the aircraft&rsquos operational service.

Although historically the Ki-109 only saw limited use at the end of the War where it was defending the Japanese home islands, in War Thunder, our battle-hardened veterans will also have the chance to take the fight to the enemy and truly show what the Peggy is capable of! Being relatively fast and nimble for it&rsquos size, while possessing a monstrous 75mm anti-air cannon, makes the Ki-109 present itself as not only a serious threat to enemy bombers, but also to unsuspecting fighters.

Contrary to his older brother, the Ki-109 is unable to carry any additional secondary weaponry as the bomb pylons, along with most of the defensive turrets, had to be removed in order to save on weight, allowing for the installation of the the Type 88 75mm cannon. The cannon makes short work of just about anything that crosses its line of fire, from heavy bombers to heavy tanks.

While the HE shells prove to be absolutely devastating against aircraft and lightly armored vehicles, where one hit is usually more than enough to send the opponent back to the hangar, the AP rounds have enough penetrating power to slice through the armor of even the more thick-skinned enemy tanks that the Ki-109 will meet in battle. This, combined with the favorable flight performance and stability when firing, make the Ki-109 a very potent and fearsome opponent to meet in an aerial engagement.

However, aspiring pilots of the Ki-109 need to take into account that their only frontal armament, the 75mm cannon, has a very limited ammo capacity of only 15 rounds. Efficiency is the name of the game here, meaning that the pilots of this machine will have to chose their engagements carefully and only fire when a hit is guaranteed, otherwise they run the risk of running dry on ammo without doing any damage.

The Ki-109 will join the ranks of the Japanese heavy fighter line in the intermediate ranks in the upcoming update 1.71. Although the history of this aircraft may not have been as significant as of others, the mark that the 75mm cannon will leave on your opponent's vehicle is sure to be everything but insignificant.

Mitsubishi Ki-109 Heavy Interceptor with 75mm Type 88 cannon

Gaijin did say they would be adding more Japanese CAS, this would be lovely to see.

I have a good feeling this will be 1 of them tbh.

The designation Mitsubishi Ki-109 was used for two different attempts to produce an interceptor based on Ki-67 heavy bomber that would be capable of shooting down the new B-29 Superfortress.

The first design, suggested in November 1943, was for a 'Killer-Hunter' team of two aircraft. The Ki-109a would have been the killer, armed with two obliquely mounted 37mm Ho-203 cannon, while the Ki-109b would have been the hunter, equipped with radar and a nose mounted 40cm searchlight.

The second design was proposed by Major Hideo Sakamoto, the officer in charge of the Ki-67 evaluation programme. He suggested mounting an Army 75mm Type 88 anti-aircraft cannon in the nose of the Ki-67. This would reduce the speed and manoeuvrability of the aircraft, but allow it to operate outside the range of the B-29's guns, and was produced in the belief that the American bombers would be forced to operate without fighter cover.

This second design was approved on 20 February 1944. The prototype Ki-109 retained the defensive guns of the Ki-67, but with a new nose and stronger fuselage. From the third aircraft the dorsal turret and lateral machine gun positions were removed. The prototype was completed in August 1944, two months after the first B-29s appeared over Japan, and production began later in the same year. Twenty two aircraft were produced using the Ha-104 engine as the Ki-109-I. They were to be followed by the Ki-109-II, using the 1,900hp turbo-supercharged Ha-104ru engine, but this version never entered production.

The 107th Heavy Fighter Regiment was formed in November 1944, and received its aircraft in 1945. The Ki-109 failed to live up to expectations. The production Ki-109-I lacked the speed and rate of climb to catch the high flying B-29s on their early daylight raids, and despite a number of attempted interceptions never actually made contact with a B-29 formation. Once the Americans switched to low level night-time raids the Ki-109, which lacked radar, became completely useless, and the 107th Heavy Fighter Regiment was disbanded on 30 July 1945.

*Engine: Two x Mitsubishi Ha-104

*Maximum take-off weight: 23,810lb

*Armament: One 75mm cannon with 15 shells individually loaded by the co-pilot and one 12.7mm machine gun in tail turret

Review: Ki-109 - The Element of Surprise (A phenomenal bomber hunter that will struggle outside of optimal conditions)

In this week's review I thought I would review the Ki-109 (Tier III Battle Rating 4.7 Japanese Heavy-Fighter Interceptor) due to popular demand.

If you are interested in knowing more about the history behind the Mitsubishi Ki-109 from its inception through to its combat service or how the Ki-109 handles (in my opinion) in Arcade this video may be of use to you.

Note: I have reviewed the plane in its fully upgraded (i.e. "spaded" form), not its stock form.

Additionally, please see below for a summary of my review in bullet point form:

Highly sustainable climb-rate - Whilst it may not have the climb-rate of a Ki-84 Ko or a F8F-1 Bearcat, one of the Ki-109's hidden strengths is its ability to gain vast amounts of altitude in a single climb thanks to its sustainable climb-rate. This helps to offset the plane's "Fighter" spawn meaning you can reach the higher altitude regions of the sky (i.e. 4000m+) shortly after your team's fighters/interceptors and be ready to intercept the enemy's bombers.

Quite durable - When pursuing enemy bombers or attempting to evade enemy fighters/interceptors, you should not be afraid to take hits. Reason being: the airframe of the Ki-109 is able to absorb a considerable amount of damage from weaponry of 20mm in calibre or less. The same. applies to the plane's engines (i.e. performance only drops off when they turn red), but not to its control surfaces which can be crippled rather quickly (particularly the rudder).

Excels in its intended role - If used purely as a bomber hunter, the Ki-109 can prove very effective as its armament speed and maneuverability combine well together to allow you to hunt down the bombers you will encounter. On the other hand, using the Ki-109 outside of this role will prove a serious challenge as you will out performed by the vast majority of the fighters/interceptors/heavy-fighters you encounter, meaning you will have to play smart and within the plane's limits.

Poor aileron control at high-speeds - When taken above its ideal speed range of 350-500km/h, the Ki-109's ailerons suffer immensely meaning your already awful roll-rate will be compromised by a further 75% between 550-700km/h. Moreover whilst the plane's rudder does not lock-up at high speed if used alone, when it is used in conjunction with the ailerons it will experience the same lock-up penalty. This will make following targets in a high-speed dive very difficult.

Near useless defensive armament - The defensive 12.7mm Ho-103 machine gun can net you the occasional assist, but has very little value beyond this. To do considerable damage with this gun you will need to let your opponents get close (i.e. <500m), but by this point it is highly likely your plane will have already been torn apart by your pursuer's firepower. The same applies to using the gunner to warn you that someone is on your six as by the time you get this warning, it will be too late.

Final Thought

When given the space to freely operate at high altitude, the Ki-109 makes for a phenomenal bomber hunter and can even have some fun against climbing fighters/interceptors. Unfortunately these ideal conditions are not always guaranteed and can leave a lot to be desired when you are having to try and pick off foes at low altitude or sneak you way into the higher altitude spaces without the enemy team noticing.

Mitsubishi Ki-109 - History

Several experimental versions of the Ki-67 were designed in the last years of the war. The only design of any consequence was the the transformation of the Ki-67 to a heavy fighter. Twenty-two planes of this model, known as the Ki-109, were built. The only differences from the original were in the armament and the forward part of the fuselage. The glassed-in nose was replaced by a faired 75mm cannon. This gun had 15 projectiles. It was to be used against the American B-29s at high altitude. Test results were satisfactory, but by the time a sufficient number of aircraft were ready, there had been a radical change in Allied tactics and the planes were no longer needed, because the B-29s began making night raids at low altitude.

Mitsubishi Ki.109

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Japanese Aircraft of WWII

In 1939 the Imperial Japanese Navy drew up its specification for a carrier-based torpedo-bomber to supersede the Nakajima B5N. The specifications issued by the navy called for very modern characteristics. A maximum speed of 288 mph (463 km/h), a cruising speed of 230 mph (370 km/h) and a range of 1,000 nautical miles (3335 km) without a bombload. To meet the requirement, Nakajima decided to use an airframe very similar to that of the earlier aircraft, differing primarily in its vertical tail surfaces. The navy had specified use of the Mitsubishi Kasei radial engine, but Nakajima decided to use instead its own 1,870 hp (1395 kW) Nakajima NK7A Mamoru 11 radial engine of similar output driving a four bladed Hamilton type propeller. The first of two prototypes was flown in spring 1941, but initial flight testing revealed a number of problems, including engine vibration and overheating, but the most serious was that of directional stability, requiring revised vertical tail surfaces. Final flight testing carried out aboard the aircraft carriers Ryuho and Zuikaku in the end of 1942, revealed further problems with the tuning of the engine and the need to reinforce the arrester hook and landing gear. It was not until February 1943 that the type entered production as the Navy Carrier Attack Bomber Tenzan Model 11, company designation Nakajima B6N1, incorporating a number of refinements as a result of extended flight testing. However, after only 135 production Tenzan (heavenly mountain) aircraft had been delivered a new crisis arose when Nakajima was ordered to terminate manufacture of the Mamoru engine, and use the more reliable 1,850 hp (1380 kW) Mitsubishi MK4T Kasei 25 engine, a step also taken to allow greater emphasis to be placed on production of the widely-used Nakajima Homare and Sakae engines.

The company was now compelled to use the engine which the navy had specified originally, the Mitsubishi Kasei, but fortunately the adaptation of the B6N airframe to accept this powerplant presented no major difficulties. The resulting aircraft, which was also the major production version, had the designation B6N2 and differed only from the B6N1 by the installation of the Mitsubishi Kasei 25 engine. The B6N2a variant had the rear-firing 7.7 mm (0.303 in) machine-gun replaced by one of 13 mm (0.51 in) calibre. When production ended, Nakajima had built a total of 1,268 B6Ns of all versions, this number including two modified B6N2 airframes which had served as prototypes for a proposed land-based B6N3 Model 13. The powerplant had been the improved 1,850 hp (1380 kW) Mitsubishi MK4T-C 25C version of the Kasei engine and the strengthened landing gear had larger wheels for operation from unprepared runways, but production did not start before the war ended. Allocated the Allied codename 'Jill', the B6Ns saw intensive use during the last two years of the war for conventional carrier operations and, in the latter stages, in kamikaze roles.

Nakajima B6N2 - Nakajima was ordered to cease using the Mamoru engine and use instead the Mitsubishi Kasei 25 engine, thus resulting in the redesignated B6N2. Although the Kasei 25 was slightly less powerful, this was offset by introducing a less drag version of the exhaust ports which also gave a slight jet-thrust like boost effect.

Nakajima B6N2a - This type differed from the B6N2 only by having a rear firing machine gun of 13 mm (0.51 in) calibre, instead of the 7.7 mm (0.303 in) type used on the B6N2.

Nakajima B6N3 - Two conversions of the B6N2a resulted in the B6N3 prototypes equipped with 1,850 hp (1380 kW) Mitsubishi MK4T-C Kasei 25C engines for evaluation as land based bombers.

(Navy Carrier Attack Bomber Tenzan "Heavenly Mountain" Model 11 - Nakajima B6N2)

Type: Three Seat Carried based Torpedo Bomber

Design: Nakajima Hikoki KK with Kenichi Matsamura as led Technical Director

Manufacturer: Nakajima Hikoki KK

Powerplant: (B6N1) One 1,870 hp (1395 kW) Nakajima NK7A Mamoru 11 14-cylinder radial engine. (B6N2) One 1,850 hp (1380 kW) Mitsubishi MK4T Kasei 25 14-cylinder radial engine. (B6N3) One 1,850 hp (1380 kW) Mitsubishi MK4T-C Kasei 25C 14-cylinder radial engine.

Performance: Maximum speed 298 mph (480 km/h) service ceiling 29,660 ft (9040 m) initial climb rate 1,885 ft (575 m) per minute.

Range: Normal 1,084 miles (1745 km) Maximum (overload) 1,892 miles (3045 km) on internal fuel.

Weight: Empty 6,635 lbs (3010 kg) with a maximum take-off weight of 12,456 lbs (5650 kg).

Dimensions: Span 48 ft 10 1/2 in (14.90 m) length 35 ft 8 in (10.87 m) height 12 ft 5 1/2 in (3.80 m) wing area 400.42 sq ft (37.20 sq m).

Armament: One 7.7 mm (0.303 in) Type 98 machine gun manually aimed from rear cockpit and one manually aimed by middle crew member from rear ventral position and one fixed 7.7 mm (0.303 in) Type 98 machine gun in left wing (often absent from the B6N1). A 1,764 lbs (800 kg) 18 inch torpedo carried offset to the right of centreline, or six 220 lbs (100 kg) bombs carried under the fuselage.

Variants: B6N1 (Mamoru engined), B6N2 (Kasei engined), B6N2a, B6N3 (prototypes for land based version).

Avionics: Some later models were equipped with ASV radar for night operations.

History: First flight March 1941 service delivery (B6N1) early 1943 service delivery (B6N2) December 1943.

Imperial Japanese Army and Navy – Night fighters

In the Imperial Japanese Army and Navy there was no alternative to visual recognition, because until early 1944 neither service used any avionics apart from communications radio and DF loops. AI radar and IFF were slow to come into Japanese service, though preliminary information on FuG 202 Lichtenstein was sent by submarine from Germany in 1942. But it would be misleading to picture Japan as a land of technology illiterates, able only to copy Western innovations. This image may have comforted the Allies until the first few days after Pearl Harbor, but it was knocked for six by the superior combat performance of the A6M (Zero) fighter, and it never had much basis in fact. In 1928 Okabe in Tokyo had been the first microwave worker to generate enough power for communications in this band of new centimetric wavelengths, and at about the same time Professor Yagi had devised the short-wave directional aerial that bears his name. Comprising a linear array of dipoles, the Yagi aerial is today seen on many millions of rooftops around the world, and it was this type of aerial that was used in the first Japanese AI installation.

Though their development was slow and often troublesome, no fewer than five types of airborne radar were worked on by the Japanese in the Second World War. At first the main effort went into ASV (air-to-surface vessel) sets, which by 1944 were operational in several types of Navy aircraft down to the familiar B5N (‘Kate’) torpedo-bomber. The three types of AI radar for night fighters were less successful. One was an Army copy of FuG 202, and though it was tested in an obsolescent Mitsubishi Ki-21 bomber in 1943 it either never reached combat units or made only an insignificant impact on operations. The much more important Army set was the E-1, operating in the S-band at near 11 cm wavelength, the main carrier of which was the Kawasaki Type 2 heavy fighter, also called Ki-45 Toryu (dragon-killer) and known to the Allies as ‘Nick’. Originally a day long-range fighter, with forward-firing guns, the Ki-45-Kai-C (modification C) version appeared in June 1944 with two 20 mm guns mounted obliquely in the mid-fuselage and, in some aircraft until October 1944, a searchlight in the nose. Gradually the AI radar was fitted and operators trained, but there is no evidence that radar played the central role in the occasional successes scored by these aircraft defending Japan against the B-29. At least the Ki-45 could reach the B-29 attack height of around 31,000 feet, and at full throttle could just overtake the speedy American bombers. Over Japan there was often chaotic radio communication, and no GCI system at all. Night fighters were thus left to their own devices, and the few successful night interceptions that took place were usually on moonlit nights when the B-29 contrails showed up from a considerable distance.

Intercepting a B-29 formation called for great courage. Whereas a Luftwaffe NJG pilot had nothing to fear from 99 per cent of the RAF heavies, the B-29 had no blind spots and carried heavy armament covering every possible direction of attack. Downwards and to the rear a fighter could be seen from three sighting stations and fired upon by six 0.5 in guns and a 20 mm cannon, and as these great bombers held tighter formation than the RAF bomber stream it was probable that, if one bomber opened fire, several others would open up on the same target. Added to the fact that head-on attacks were impractical at night, one is left with a situation in which a single fighter is faced with withering heavy-calibre fire in a stern chase at a closing speed hardly more than walking pace. A few Ki-45 night fighters attempted to get more speed and altitude by fitting only two 12.7 mm (0.5 in) oblique guns, a totally inadequate armament for the task of bringing down a B-29. Typical Ki-45-Kai-C forward-firing armament comprised a single heavy cannon of 37, 50 or 75 mm calibre, but these fired slowly and carried a very limited number of rounds. How eight of these fighters managed to bring down seven of a force of B-29s attacking northern Kyushu on the night of 15 June 1944 remains a mystery: there may have been some deliberate collisions.

The equivalent of the Ki-45 in the Imperial Navy was the Nakajima J1N1 Gekko (moonlight), called ‘Irving’ by the Allies. Planned as an escort fighter in 1940, the original J1N1-C failed to make the grade, but eventually entered service as a reconnaissance aircraft. It first operated in late 1942 in the area of New Guinea and the Solomon Islands, and though it had inadequate performance for day fighting it was locally judged to be a possible answer to the US Army heavy bombers that were making life a misery at night. The initiative to turn the J1N1-C into a night fighter stemmed from the commander of the 251st Air Corps at Rabaul, Yasuna Kozono, who proposed the same upward-firing armament as was being experimented with by the Luftwaffe. He went further, and suggested two pairs of 20 mm Type 99 Model 2 cannon, one pair firing obliquely up and the other pair obliquely down. Compared with the Luftwaffe Schräge Musik installations the inclination was less steep, a typical angle being 30°.

In March 1943 Kozono received permission for the proposed modification, and two aircraft were returned to Japan for this purpose. At the same time the Navy Bureau of Aeronautics in Tokyo recognized that the basic aircraft was eminently suitable for use as a night fighter, a category of aircraft then non-existent in the Imperial Navy. Work began on a specialized sub-type, the J1N1-S. Meanwhile the first two night-fighter conversions, designated J1N1-C-Kai, returned to Rabaul in May 1943 and soon proved their worth by shooting down two B-17s, following the next night by a B-24. This was no mean achievement, as the C-Kai had long exhaust stacks discharging above the wing, without flame dampers, and maximum speed not higher than 300 mph. At one time one of them had a trainable searchlight in the nose. They retained a crew of three, the pilot being assisted by a navigator and a gunner, the latter being needed to change ammunition drums.
These successes, the first ever gained by Japanese night fighters, were followed by others until both the original C-Kai conversions had been destroyed. But by August 1943 the definitive J1N1-S Gekko was in production, and most of the 479 of all J1N versions built were of this sub-type. The new Type 99 Model 2 guns had belt feeds, so no gunner was needed, and the previously lumpy rear fuselage was made more streamlined. From December 1944 the Gekko was the chief Navy night fighter, but its success against the B-17 and B-24 could not be repeated against the B-29 it could not climb high enough nor fly fast enough, despite the speed being increased to 315 mph at the best height of about 16,000 feet and 272 mph at 30,000 feet. In the final versions produced in 1945 a Navy-developed AI radar was fitted, again using Yagi-type aerials in a neat quadruple array and being under the control of the observer. There is no record of successful B-29 interceptions, and these aircraft either languished on the ground or were used for Kamikaze attacks.

The Army’s success with the Ki-45 led to a successor, the Ki-96, first flown in September 1943. Much more powerful, it had a speed of 373 mph and carried a 37 mm cannon and two 20 mm guns. The Army could not make up their minds whether it should have one seat or two. Eventually the Ki-96 was redesigned into the Ki-102 two-seater, flown in March 1944. One of its guns had a calibre of 57 mm, and a single shell blew an engine off a B-29 in the course of a prototype test flight with loaded guns. Only a handful of different types of Ki-102 were built, the last two being Ki-102c night fighters with two oblique 20 mm Ho-5 cannon and two forward-firing 30 mm Ho-105s. All these were new guns marking a great improvement on the old patterns used previously. The Ki-102c also carried AI radar, almost certainly E-1, and its crew comprised a pilot and radar observer. The Allied name for all Ki-102 versions was ‘Randy’.

It so happened that the best of all Japanese night fighters was a converted bomber extremely similar to the Ju 88 in character. Though many years later in conception than the German aircraft, the Yokosuka P1Y1 had precisely the same wing span, almost identical weights and engine power, a close-grouped crew of three and very similar flight performance. Like the Ju 88 it was big, tough, durable and could be flung round the sky like a single-seater. So good was it that the Navy instructed the Kawanishi company to redesign it into the P1Y1-s Kyokko (Aurora), known to the Allies as ‘Frances’. The tricky airframe was made simpler to build, the troublesome Homare engines were replaced by robust Kaseis, and the interior was rearranged with the navigator in the nose, the pilot in the centre and the rear gunner in the aft cockpit. The usual armament comprised two oblique 20 mm guns (said to be Type 99 but almost certainly Ho-5s) and a third gun of the same type in the rear cockpit for defence. Radar was fitted, related to that of the J1N1-S but derived from the widely used ASV installation with a completely different dipole aerial array, there being a single large Yagi array in the nose and an axial trio of dipoles along each side of the rear fuselage. About ninety-seven Kyokkos were built, a few having a twin 20 mm dorsal turret. It was perhaps fortunate for the Allies that protracted trials were still going on when the war ended.

There were many other ‘heavy fighter’ programmes in Japan which might have yielded a useful night defender. Among these were the Ki-46-III-Kai version of an established reconnaissance machine, with an oblique 37 mm cannon the big Mitsubishi Ki-109 with a forward-firing 75 mm gun the Nakajima J5N-1 Tenrai (heavenly thunder), designed to replace the J1N1-S the Kawasaki Ki-108 with twin turbocharged engines and a pressure cabin the Rikugun Ki-93, with two six-blade single-rotation propellers and the Mitsubishi Ki-83, which was one of the best combat aircraft the Japanese produced in the Second World War. None of these played any part in the war, owing to a combination of muddled administration, severe technical snags, crippling shortages, and the catastrophic effect on Japanese industry of the devastating B-29 raids. Unlike the air battles in the German night sky, those over Japan – if they took place at all, which was very seldom – were one-sided. The general objective of the Japanese was not so much to develop a better fighter that would destroy the B-29 faster, as to develop one that could actually get within firing range. There was quite a difference between a Lancaster cruising at 200 mph at 22,000 feet and a B-29 cruising at 300 mph at 32,000 feet. This must be borne in mind when reflecting on the Japanese lack of success.