Micubiši J2M Raiden [Jack]

Mitsubishi J2M - an overview of the versions

Japanese name: 雷電 - Raiden - Thunderbolt (jap)

Allied code name: Jack

局地战斗机"雷电"/ - / Naval interceptor fighter Raiden

Mitsubishi J2M1
- a prototype based on the specifications of the 14-Shi, featured a new concept of a fighter for the land base. During testing resulted many serious defects, therefore, was radically altered.

Mitsubishi J2M2 11
- characteristic was the gradual start of production, there remain difficulties in landing and also the injection of chemicals into the engine, the total was made 155 pcs.

Mitsubishi J2M3 21
- production takes place in parallel with the previous type, the armament consists of 4x cannon caliber 20 mm, included in the defense of the parent islands were built in total 260 pcs.

Mitsubishi J2M4 32 and Mitsubishi J2M4 32 Kai
- substantial adjustment to the fuselage, which brought improved view from the cockpit, the engine přeplňován engines. A total of two prototypes were built a different type of compressor.

Mitsubishi J2M5 33
- have been retained adjustments of the hull from the previous type and the installed engine from the J2M3. The use is aimed for the fight with B-29, therefore, the amplification equipment. Nedoložen the exact number of produced aircraft of this version - probably 43 aircraft.

Mitsubishi J2M6 31
- this version was probably made in only two specimens was used elements of the J2M3 and polokapkovitou cabin as the J2M5

Mitsubishi J2M7 this was the machine J2M2 with high-rise engines MK4U-A Kasei 26


A total of were produced 480 Raidenů
Production took place at Mitsubishi Jukogyo Kabushiki Kaisha in Nagoya and Suzuka(476 aircraft) and in Goat Kaigun Kokusho (Naval arsenal of the Goat).

Mitsubishi J2M Raiden / Jack[/heading]

History & development:

Command of the japanese navy air force (海軍航空本部 Kaigun Kōkū Hombu) in September 1939, the ministry issued specification 14-Shi in which zformulovalo your requirements for a completely new type of aircraft - the overflow jet. This fighter was to operate exclusively from land bases. A tactical fighter should be capable of rapid ascent and flight at great speed to capture and subsequently cannon armament to destroy enemy bombers. At that time in the japanese naval air force was the release of such requirements to a revolutionary step. In the command Kaigun Kōkū Hombu was a very strong group of senior officers, only promoting the construction of an extremely resourceful aircraft with long range, a typical representative of the tank of such a concept was on-board Zero. In the new formulation requirements, however, the main emphasis was on the contrary put on the completely different characteristics of the overflow tank, the required performance and firepower.
In April of the following year were the specifications specified and newly requested e.g. the effective armour of the pilot's seat, also in the technical requirements were reflected to the japanese news information on upcoming and newly manufactured of american bombers. Technical department Kaigun Kōkū Hombu for the compilation of requirements was used also by my own experience from fighting in China.

These modified technical specifications answer the company 三菱重工業 - Mitsubishi Jūkōgyō Kabushiki Kaisha (hereinafter referred to as Mitsubishi), and the project began to work her a successful chief designer engineer Jiró Hirokoshi, whose team were ranked also Mijiró Takahashi and Ishitoshi Sone and just Takashashi later took over the leadership of the design team, because Jiró Hirokoshi was quite busy the evolution of the Zero. A new project was factory marked as M-20, but the work did not progress rapidly because the interceptor did not předělenu the necessary priority. Officials of the navy was for approval to submit a project of metal aeroplane and since the important feature should be high speed and climb, was to drive the new machine selected the čtrnáctiválcový air-cooled engine Mitsubishi MK4C-A Kasei 13, with a displacement of 42,1 l and, with a starting capacity of 1 430 horsepower. Engine powered trojlistou variable pitch propeller with constant speed. This type of power unit was both powerful, but also quite bulky and so it was, according to the design engineers, rather just kapotován. On vrtulovém the shaft was a fan, who assisted the forced cooling. The submitted project was approved almost without comment, and so Mitsubishi has acceded to the construction of prototypes, however, still with low priority.

Flight features new aircraft, whose first prototype took off up to 20. in march 1942, were not bad, but it was a completely new type of and so, quite logically, the adjustments carried out and some were fairly fundamental, adjusted was the mechanics of the chassis, then the design team struggled with overheating the engine, it was the tax for his tight kapotování and also the entry of cooling air was narrow. A separate chapter for the first machines was a bad view at startup and during landing, here the pilots hated the dimensional engine that almost did not allow views of the runway and also the front label of a small and low-pilot of the cover, which, moreover, strongly interfere with the view out. Problematic was the automatic readjustment of attack of the blades, works smoothly and the overall reliability of this device was limited. Drive unit additionally suffered from vibration. The wing was used modern, with a profile allowing laminar air flow, moreover, was equipped with flaps, which improve the maneuverability of the airplane. In the wings were two dvacetimilimetrové cannons the Type 99-1 Model 3, these canons were supplemented by a pair of machine gun Type 97 caliber of 7.7 millimeter stored above the engine. The prototypes (there were built a total of eight), were below the calculated performance. The first three machines, which were the maritime air force accepted as the J1M1 with combat on behalf of the Raiden (Thunderbolt) are calculated between the prototypes and also your making prototypes match.

Other machines have already been made in the version of J2M2 11, this version was equipped with more powerful engine MK4R-A Kasei 23a, the provide during the take-off of the already solid performance of 1 800 hp and powered a four-blade propeller (licence VDM) with constant speed. This engine has been shortened shaft of the fan and it managed to remove unwanted vibration, but not completely - to increase the performance of the engine was equipped with a device for injection of the mixture of water and methanol into the compressor. Unfortunately, this was the yet unripened device, as a result of its use increased the speed of the engine, that is the end of the blades were in the area of speed of sound and this phenomenon subsequently caused dangerous vibrations, which are passed on to the whole engine (this engine type was used for the following version of the J2M3, J2M3a, J2M6 and J2M6a). Further, an adjustment was made to the fuel system of the aircraft. The engine cover was shorter and more open, thus increased the flow of cooling air. The new version of Raidenu carried the same armament as the previous J1M1. The first aircraft of this version Raidenu flew in October 1942 and later this month they launched a serial production, however, this was a very, very, very, slow pace and during the following five months it was completed only 14 aircraft! The situation only gradually changed and by February 1944 there were produced about 155 aircraft of this version. The factory in Nagoya had been very busy making much-needed Zer and difficult to looking for available production capacity for Raideny. This situation has in turn forced the Kaigun Kōkū Hombu to change the attitude to the private activity of the company 川西航空機株式会社 – Kawanishi Kōkūki Kabushiki Kaisha and took one of her prototype of the overflow jets for testing and subsequently for the assistance of naval specialists and the release of finances arises fighter N1K Shiden.

Another version of the Raidenu was the most widespread and appeared exactly a year after the previous one, i.e. in October 1943. Has been marked as J2M3 21 and you could characterize the changes, which are mainly related to the glazing of the cabin, the windshield of the equal bulletproof glass, he has however view. Another change has undergone a aircraft armament - were removed the fuselage machine guns, but in each half of the wing was a pair of powerful cannons Type 99-2 Model 4 with a stock of 210 rounds of ammunition and the Type 99-1 Model 4 190 grenades*. There was still ordnance department variant J2M3a 21A Ko, which should have all weapons of the same type - cannons Type 99-2 Model 4, this variant was produced in a small number of (apparently 21 aircraft), so the production added Raideny version of the J2M3 in the total number of 281 piece (260 + 21). Reservations pilots are still related to bad vision especially at startup and during landing. The pilots, who were crossing the Raideny of Reisenů hardly put up with the dexterity, or rather the ease of ambush fighters, but if it was compared Raiden Shidenem (N1K1-J) came out Raiden supposedly as the winner.

Another version, was this time rather experimental Raiden J2M4 32 built most likely in only two prototypes, this version is from the other Raidenů different used type of engine Kasei 23c MK4R-C. This engine was turbocharged engines and each of the two prototypes used a compressor from another manufacturer. Engine performance, however, was similar, but what was most important – both of the war were just as unreliable and immature for operational deployment. The production of the compressor is very challenging after page of metallurgical and machine production, that in the Japan it was not possible to produce 100% functional supercharger. However, if the compressor worked, provided as follows turbocharged engine at a height of 9 200 m performance 1 440 horsepower and performance of this Raidenu were excellent. In some sources it is stated that this has been adjusted and a few other Raidenů, further mention the one treated in such a way (I don't have the possibility of verifying). An equally important reality, however, was the fact that engineers managed to modify the hull (i.e. cut) so that they improved at least a view in flight and it not only forward but also backward. The first prototype carried in the wings of the four cannons and the other was about two wing lightened.

The hull, which are at least partly managed to improve the view, is left unfulfilled and instead of turbocompressors engine was installed a new high-altitude engine Kasei in version 26a (MK4U-4), which was effectively přeplňován třírychlostním mechanical compressor and at an altitude of 7,200 meters was still performance 1 310 horses, by joining the hull and the engine formed the fastest version Raidenu J2M5 33. This version was at a height of 6 600 m, a maximum speed of 615 km/hr and at a height of 8 000 m, it was still very decent 603 km/h. the First aircraft of this version flew in may 1944, but the production ran until June of 1945, because they were not available engines with třírychlostním compressor. A distinctive feature of this version is the smaller oil cooler under the engine and the more protruding the cabin. Two ordnance department variants existed, as well as with the older vega J2M3. One aircraft of this version was armed with a pair of completely new třicetimilimetrových cannons Type 5 , these canons were supplemented by a pair of the usual-twenties, but the Type 99-1 Model 4, I couldn't figure out whether this modified aircraft was differently marked. Version of the J2M5 was really powerful, but to the detriment of the japanese naval air force, was delivered only in small quantities - 43 aircraft.

A modified hull with a better view and the older engine Kasei 23a MK4R-A (i.e. with a larger oil cooler) along with armament of two cannon Type 99-1 Model 4, and two more powerful Type-99 Model 4, then it was Raiden J2M6 31 and if the armament was composed of only four cannon Type 99-2 Model 4, then it was a variant of the J2M6a 31A. Just the numerical designation of the model of the us by japanese naval aircraft will tell you that it was about the third adjustment airframe and one again, the engine is first used in a row. This version was produced in parallel with the previous version, but the number of produced aircraft is not known, but certainly was short (apparently the two aircraft).

Already from the version then was J2M7 23, which was the hull of older J2M3, but with the elevation motor Kasei 26a and even here there should be two ordnance department variants, 23 and 23A.

There still remains to mention the non-standard adjustment Raidenů, which was conducted gunsmiths from 302. Kōkūtai, this unit was commanded by us the well-known "father of night fighters" 海軍大佐 Kaigun Daisa (captain) Yasuna Kozonó**, who had mounted obliquely set cannons into the hulls of all the planes that this unit had in its arsenal. This adjustment is denoted by and its Raideny, back in the cabin of the pilot was in the left half of the installed one gun the Type 99-1 Model 3 with bubnovým magazine for 100 rounds. Japanese sources do not mention whether he was a bomber shot down just this gun. However, it is clear that the pilots of this unit were not the most experienced fighters, because they were mostly moved pilots from the dissolved units of the bombers and the flotation of the aircraft, but even here there were several fighter ec as (海軍中尉 Kaigun Chūi ) lieutenant Sadaki Akamatsu (27 kills), (海軍大尉 Kaigun Dai) captain-lieutenant Chitoshi Isozaki (12), (兵曹長 Hikō Heisōchō) ensign Ioshio Nakamura (9) (海軍中尉 Kaigun Chūi) lieutenant Sachio Endó (8). Pilots of this unit were quite successful in the fight with Superfortressy, but eventually they were and they destroyed the american numerical predominance of naval and army fighters.

Martial operating activities:

The first unit, which Raideny include this in your loadout at the end of the year 1943, was 381. Kōkūtai, in February 1944, had in its arsenal besides the usual fighters A6M5a Reisen also 10 Raidenů in version J2M2, in fighting this unit hit during the following months, operated from a base Balikpapan in Borneo from the base Raikan on Celebesu. The task of 381. Kōkūtai was the defense of the oil fields in Borneo. This unit was still in the spring of 1944 reorganized and all Raideny were concentrated at 602. Hikōtai, which, with its Raideny operated from a base in Kendari. Pilots of this unit participated in the September's successes throughout the 381. Kōkūtai, when the Americans lost 19 Liberatorů and less than ten fighters Lightning and Thunderbolt. Americans due to the appreciable losses of bomber aircraft subsequently increased the number of accompanying fighters, due to this measure, significantly increased losses on the japanese side and from the daily attacks had to be completely withdrawn twin engine fighter J1N1 Gekko. The end of the year Raideny 602. Hikōtai get into fights about Philippines, when vzlétaly from the base Nichols Field. In April 1945 was the whole of the 381. Kōkūtai withdrawn to replenish and training on maternity islands. Another unit having a Raideny in its arsenal was 301. Kōkūtai, namely its 601. Hikōtai, where they were Raideny at least initially concentrated. This unit had a base near Nagoya, in the fighting hit her 316. Hikōtai over Iwo Jimou and after losses I was moved and 602. Hikōtai, its pilots, however, on Iwo Jima, they took rather Reiseny, whom they trusted more. During a single month was all 301. Kōkūtai completely and almost completely destroyed, they took care of it the american naval fighters, who had over the Japanese multiple numerical superiority. Another unit having a Raideny in the state was 302,332. Kōkūtai that with them first, protect a naval base in Kur and later from the airport in Naruo protect the big cities of Kobe and Osaka. Pilots of this unit your Raideny and Reiseny very successfully fought against nalétávajícím Superfortressůmprobably the most successful fighter of this unit was (海軍中尉 Kaigun Chūi) lieutenant Susumu Ishihara (16 kills). Raideny was equipped with the 352. Kōkūtai, which quite successfully intervened in the fighting over the cities Nagasaki, Sasebó and Ómura, its combat activities ended in the battles over Okinawa. An interesting grouping was a special unit Tatsumaki-tai, was a unit formed by the members and Raideny two Kōkūtai and 20 Raidenů from the 302. Kōkūtai and 16 of them were from 332. Kōkūtai. The task of this unit was mainly the fight against Superfortressům, operated on from between 26. April and 10. may 1945 from the airport to Kanoya, the enemy were inflicted appreciable losses, but in the end this unit ceased to exist, because the pilots did not airworthy machines. In small quantities (up to 5 planes) were Raideny in these units: 256. Kōkūtai, 1001. Kōkūtai, 2081. Kōkūtai, Yokosuka Kōkūtai, Yotabe Kōkūtai, Genzan Kōkūtai, Tainan Kōkūtai, Kónoike Kōkūtai and Chúsui Kōkūtai.

Rating:

If he was Raiden piloted by an experienced pilot, who could take advantage of his strengths, was it plane a good, which won the respect of the allied pilots, could endanger the next B-24 Liberator even more powerful and more durable B-29 SuperFortressy. Such fighters were not many in Japan, therefore, the units were with Raideny assigned primarily to air defense of Japan. Against maritime Hellcatům and Corsairům could Raiden boldly stand up if it was piloted by an experienced pilot could outmanoeuvre also army fighter P-38 Lightning and P-47 Thunderbolt, even though in particular Thunderbolt was the tougher opponent, P-51 Mustang was Raidenu superior in all respects.

Pilots who previously flew to the deft and light Reisenech, very often with a heavy and above all less skillful Raidenem they couldn't handle it and prefer the skillful Reiseny (example 301. Kōkūtai), on the other hand, the pilots of the 302. Kōkūtai, who flew previously with the bombers and plovákovými machine, you come to your Raidenům without prejudice, and had with them the achievements. Among the indisputable advantages of Raidenů belonged to speed, climb rate, service ceiling and, of course, effective armament, on the other hand, have suffered from such overflow aircraft some flaws. Most pilots have criticized the bad view, the designers have to tried to improve it, but such modified Raidenů already, there's not many, another problem was the vibration of the engine, about those I wrote earlier, in short – if you have used the full power of the engine, rozvibrovaly the shock wave from the end of the blades all over the engine. Compared with other naval fighters had Raiden a small range, let's leave from this comparison of the Reisen, which was extreme, but longer range had Šiden and Šiden-Kai, Šideny both version, however, had the character more of a universal airplane, whereas Raiden was from the very beginning developed and built as a trap fighter, his tactics should be the principle of "hit and run", for the flights was equipped with additional tanks with a capacity of 250, 300 and 400 liters. Towards the end of the war, the weaknesses were joined by even more inadequate workmanship.

Several Raidenů was tested by the allied pilots, complete tests were carried out after the surrender of Japan. Allied test pilots rated the Raideny in the affirmative and the engine is depicted as a "noisier" with well-resolved cooling.



<sup>Explanatory notes:
*Air cannons of the Type 99-1 and Type 99-2 were different weapons, their production was carried out in parallel, using completely different ammunition. Cannons Type 99-1 (Type 99 Mark 1 Model x) had a shorter barrel, less muzzle velocity, bullets with less weight but had higher rate of fire. Cannons Type 99-2 (Type 99 Mark 2 Model x) have been more powerful thanks to a higher muzzle velocity, higher weight of the grenade, but degrade is a small cadence. Both types of guns have a basis in the swiss guns Oirlikon cannon type 99-1 was a modified copy of a cannon FF-F and type 99-2 was coming out of a cannon FFL. The rights to their licensed production of the Japanese purchased in 1937.

** 海軍大佐 Kaigun Daisa (captain) Yasuna Kozonó is very instrumental in the formation and development of night fighters Nakajima J1N1-S Gekko.</sup>
.

Raiden in the tests of the Technical Air Intelligence Center

At the beginning of 1945 to the Americans in their advance on the Philippines near Manila managed to get two almost undamaged japanese overflow jets Mitsubishi J2M3 Raiden. The first Raiden with the serial number 3008 and with the designation of 81-124, was found at the airport Dewey Boulevard second Raiden with serial number 3013 stood at the base of Nichols Field. Both Raideny belonged to 381. Kōkūtai. The first referred to the machine was fairly soon put to flight status and was subsequently very thoroughly tested the unit ATAIU (Allied Technical Air Intelligence Unit), during these tests carried the designation S-12. It is interesting that the ratings of american test pilots is often different from the japanese naval pilots.

Cabin, the view and the noise.
American pilots who participated in these tests, first to find that Raiden has the comfortable and comfort the pilot area, although Raiden did not have kapkovitou cabin, was out of it during the flight a decent view thanks to the sufficient space, which allowed free movement of the pilot's head. With regard to the radial engine and the used type of chassis was a bad view while taxiing and during take-off and up to the moment when the left tail wheel from the earth (Raiden was in this matter rated better, than, for example, in parallel, tested fighter Nakajima Ki-84 Hayate). Partly the view was restricted somewhat wider framing canopy. Positively was assessed the fact that all the controls are easily accessible and clearly arranged. Ventilation of the cockpit was solved very well using the front and rear ventilation, also the soundproofing was quite good, the cabin was penetrating only the occasional noise. Engine Raidenu had a rather narrow entrance of the cooling air, therefore the cooling of the engine was forced, and the installed fan was the source of somewhat higher sound levels, this however, the sound was audible only from the outside of the airplane and into the cabin almost began. For this particular aeroplane was taking place in some modes of engine operation to the resonance canopy, these resonance causing an unpleasant noise to the list of noise sources is complete, so in the evaluation report it was noted that one of the sources of noise was the exhaust system. The individual exhausts were fueled in addition to the slight forward thrust and a slightly higher noise.

the drive unit.
Quite positively was evaluated the power unit, the launch was assessed as a very easy and equally reliable, and that completely regardless of the engine temperature. Rebuke earned him a hard operation of the engine when the travel speed in the auto setting mode of the richness of the mixture, if the mixture was set manually to a richer running engine to soften, but then it was necessary to control the temperature of the exhaust gas, which thanks to this enrichment quickly soared. Engine cooling and engine oil was evaluated as extremely effective, but in the evaluation report it was mentioned that the cooling of the engine gives the impression of a possible oversize, which might lead to hypothermia of the power unit during operations in cold areas, but this has not been the subject of tests. During flight tests it was found that the propeller fits in the area of normal speed, at higher speed occurs at a height of 10,000 ft (3 048 m) to vibration. Here, however, it is to be noted that the control of the rise time of the propeller of the sheet was not standard, the original hydraulic was changed to electric (I couldn't figure out whether this adjustment made the Americans or the Japanese). There were even excessive vibration of the power unit, only on the overrun of the compressor at a second speed occurred at a height of 12,000 ft (3 658 m), to their temporary rise.

Taxiing and take-off.
The maneuverability of the aircraft during taxiing good, except for the smaller efficiency of the rudder, the brakes were initially quite effective, but prone to overheating.
Thanks gyroskopickému the effect of the propeller Raiden showed efforts to take-off swerved from a straight line, this pursuit of buckling, however, was only moderate and it could be corrected even less effective rudder. The view forward is improved when after the lifting of the tail to a horizontal position, this occurred only after reaching a speed of 100 mph (160 km/h), the speed it was already quite large, this property should on the conscience of a smaller area of the stabilizer. After takeoff and after the retraction of the chassis was needed the plane only slightly offset. Raiden was immediately after take-off capable of sharply and quickly rise during this climb is very positively experienced effective cooling of the engine, its temperature was despite the full power of the engine is always optimal.

Flight characteristics.
In tests it was found that up to a speed of 325 mph (523 km/h) has Raiden really good flight characteristics, the flight was stable and the control was only good aileron control was more rigid and it is already at normal cruising speed, if then the plane flew with great speed, it was necessary to develop on their control use a great strength. Control of the rudder appeared as a completely satisfying and completely regardless of the speed of flight, also the control forces on the elevator were very small. In the report it is stated that when an inattentive piloting and using brute force may be at high flight speeds occur when damage to the airplane.
Highlighted was the excellent stability of the Raidenu, that could be violated only after nepozorném and unequal overdraft of fuel from the design team tanks, it may be that the aircraft will be heavy on one wing.
The stalling characteristics were considered and evaluated as excellent and the only identified deficiency, Raiden did not warn the pilot before the dragging, in this case, the bow almost without warning fell slightly directly, or happened to Raiden jumped after the wing, a recess was however very quick and with just a little loss of height, plus she didn't show pursuit, so jumped into a tailspin.
Acrobatic maneuvers at normal speeds, it was possible to perform very easily and lightly, the speed of rotation around the longitudinal axis was assessed as lower than that of the us Mustang. Very positively was evaluated the use of the flap type Fowler, which can be controlled using the switches on the control lever.

Summary.
Overall, it was Raiden Americans evaluated very positively and in the final summary was re-raised by the comfortable cabin, good views, the stability of an aeroplane in flight, the good performance of the aeroplane and the high efficiency of the flaps. At the same time, there were pointed out also negative features, which was a small efficiency of the rudder and decreasing the effectiveness of the brakes during extended taxiing, the other negative features was the decreasing dexterity of the aeroplane at great speeds, there was criticism of even a limited range of (Raiden was the overflow jet, whose primary task should be to fight with enemy bombers, and so would the last two listed properties tolerated)..

sources:
René J. Francillon Ph. d., Japanese Aircraft of the Pacific War, Naval Institute Press, Annapolis Maryland, Reprinted 1990, ISBN-0-87021-313-X
William Green, War Planes of the Sekond World War – Fighters, Vol. Three, London Macdonald, seventh edition, 1973, ISBN: 0-356-01447-9
Vaclav Nemecek, Military aircraft 3 part, the second edition, Our Troops, Prague 1992; ISBN 80-206-0117-1
Tadeusz Januszewski and Kryzysztof Zalewski, Japońskie samoloty marynarski 1912-1945. 2, Lampart, 2000, ISBN 83-86776-00-05
Famous Airplanes of the World, Navy interceptor "Raiden", Well. 61/ 1996, Bunrindo Co., Ltd., Printed in Japan, ISBN: 978-4-89319-058-1
Robert Peczkowski, Mitsubishi J2M Raiden, Stratus, 2004, Poland
L+K, 9/1967, and 8/1991, Aircraft 1939-45, Václav Němeček
http://www.combinedfleet.com/ijna/j2m.htm
www.century-of-flight.net
http://airu.ru/content/view/452/81/
archives of the author.