Showing posts with label Imperial Japanese Navy Air Service. Show all posts
Showing posts with label Imperial Japanese Navy Air Service. Show all posts

Bombing of Chongqing (Chungking), China

G3M bombers dropping bombs on Chongqing, China, circa 1940s.

The bombing of Chongqing, from 18 February 1938 to 19 December 1944, was a series of massive terror bombing operations authorized by the Empire of Japan's Imperial General Headquarters and conducted by the Imperial Japanese Army Air Service (IJAAF) and Imperial Japanese Navy Air Service (IJNAF). Resistance was put up by the Chinese Air Force and the National Revolutionary Army's anti-aircraft artillery units in defense of the provisional wartime capital of Chongqing and other targets in Sichuan.

According to incomplete statistics, a total of 268 air raids were conducted against Chongqing, involving anywhere from a few dozen to over 150 bombers per raid. These bombings were probably aimed at cowing the Chinese government, or as part of the planned but never executed Sichuan invasion.

Opposing Forces

China

The centralized command of the Republic of China Air Force integrated many former Chinese warlord air force aircraft and crews, and numerous Chinese-American and other foreign aviators volunteering for service with the Chinese Air Force. Nominally referred to as the Nationalist Air Force of China, at the outbreak of the air war in 1937 it was equipped mainly with US-made aircraft and training, as well as aircraft and training from other foreign sources, including Italian and Japanese army air force instructors. China was not an aviation industrial power at the time, and by the end of 1938 had suffered severe losses through attrition at the Battle of Shanghai, the Fall of Nanjing, the Fall of Taiyuan, and the Fall of Wuhan. The Chinese had found new hope in the lifeline of the Sino-Soviet Non-Aggression Pact of 1937, and Chinese Air Force pilots had almost completely transitioned into the Soviet-made Polikarpov I-15 and I-16 series of fighter pursuit aircraft by early 1938. Along with a few remaining Curtiss Hawk IIIs which were China's frontline fighter attack weapon of choice at the beginning of War of Resistance-World War II in 1937. A handful of other fighter aircraft models were also available to the Chinese, including several Dewoitine D.510 fighters left by the defunct French Volunteer Group (the 41st PS), which was disbanded in October 1938 due to difficulties in combating the Mitsubishi A5M fighter. While the Chinese victory at the Battle of Kunlun Pass kept the Burma Road open, the ever increasing Japanese blockade of imports into China, particularly after Chongqing was cut off from the sea after losing Nanning in the Battle of South Guangxi, and with war now looming in Europe, the supplies needed by the Chinese were barely trickling in, and the Chinese Air Force had to make do with the increasingly poor flying performance and maintenance problems of these Soviet-made fighters burning low-grade 65–75 octane fuel in the first few years defending Chongqing and Chengdu while massive formations of Japanese aircraft benefiting from great technological advancements and burning 90+ octane fuel were flying ever-faster and higher, almost beyond practical reach of the obsolescent Chinese fighter aircraft; the British Royal Air Force for example were supplied directly by their own aircraft industry while benefiting from tremendous improvements in their fighter aircraft speed, acceleration and high-altitude performance by upgrading from the standard 87 octane fuel to the "secret 100 octane" formula later in the Battle of Britain.

Primary and auxiliary airbases used by the Chinese Air Force in the Chongqing and Chengdu defense sector included Baishiyi Airbase, Fenghuangshan, Guangyangba, Liangshan, Shuangliu, Suining, Taipingsi, Wenjiang, and Xinjin, among others. There were 18 primary anti-aircraft artillery batteries positioned around Chongqing from 1939 to 1942, not including the air force's anti-aircraft gun units assigned specifically for the defense of the airbases.

As the Chinese government and military forces fell back and engaged the Japanese advances in new frontline operations in the beginning of 1938 at Wuhan, Taierzhuang, Guangdong and other main battle lines, the Imperial Japanese Army Air Force began harassing the deep-rear with exploratory strikes against the anticipated national fortress of Chongqing, while the Imperial Japanese Navy Air Force was hitting hard at the main battle-front of the temporary wartime-capital Wuhan. The exploratory strikes on Chongqing began on 18 February 1938, and continued sporadically at relatively low intensity until the commencement of "Operation 100" on 3 May 1939, when airbases of newly-captured territories, specifically in Hubei province including Wuhan, allowed the Japanese to establish airbases and logistics to stage a sustained campaign of massively coordinated joint-strike operations with the Imperial Japanese Navy Air Service heavy bomber units. The introduction of the Mitsubishi A6M Zero fighter in 1940, the most advanced fighter aircraft produced at the time, ensured the Japanese practically complete air supremacy. U.S. support for China had begun in earnest in 1941 following the Japanese invasion of French Indochina, with the oil and steel embargo against Japan, and consequently, the Japanese raid on Pearl Harbor; beginning in 1942, barrels of 100-octane avgas began to increasingly trickle into China through the cross-Himalayan air-route known as "The Hump" – mostly destined for United States Army Air Force (USAAF) operations – and the Chinese Air Force were provided with new American Republic P-43 Lancer pursuit planes, which in theory with its very fast high-altitude performance and good firepower from its four 50 cal (12.7 mm) M2 Browning machine guns, was quite the upgrade the Chinese Air Force needed to effectively hit back at the Japanese raiders, but it was proven to be extremely unreliable and may have killed more of its own pilots than the enemies, including veteran pilot and 4th PG CO Major Zheng Shaoyu whose P-43 caught fire during a ferrying flight back to combat operations in China and was killed in the ensuing crash.

Japan

The majority of the Japanese air raids conducted against Chongqing and other targets around Sichuan were made with squadrons of medium-heavy bombers composed of IJNAF Mitsubishi G3M variants, known under Allied codename "Nell" and the IJAAF Mitsubishi Ki-21 "Sally"; others include the Fiat BR.20 Cicognas ("Ruth"), Kawasaki Ki-48 "Lily" and Nakajima B5N "Kate". Prior to the departure of the crack Japanese naval air units in China for the Pacific War in mid-late 1941, the new successor to the G3M bomber, the Mitsubishi G4M "Betty" and the Aichi D3A dive-bomber were operationally tested in the bombing of Chongqing, followed by newer designs such as the Mitsubishi Ki-67 "Peggy", Nakajima Ki-49 "Helen", and Yokosuka P1Y "Frances" (successor to the G4M), which were deployed in the following years as the bombing of Chongqing continued.

Raids

In the first two days of the Operation 100 bombing campaign, 54 and 27 Japanese bombers raided Chongqing on 3 and 4 May 1939 respectively, dropping approximately a 3:2 ratio of Type 98/25 high explosive "land bombs" (98 dropped on day one) and Type 98/7 incendiary bombs (68 dropped on day one). The first raid killed almost 700 residents and injured 350 more. Major Deng Mingde led the 22nd Pursuit Squadron (of the 4th Pursuit Group) Polikarpov fighters against the bombers on 3 May, shooting down seven bombers but losing two pilots including his deputy commander, the veteran Zhang Mingsheng. Zhang tried to save his damaged plane, but it became engulfed by fire, and while bailing-out and parachuting to safety, he was severely burned; he was then attacked by locals who thought he was a Japanese airman as he laid on the ground, barely able to mutter a sound to identify himself, and rescued four hours later, succumbing to his battle wounds the following day in a hospital.

The pre-dawn attack on 4 May resulted in far more casualties, with over three thousand deaths, injuring almost 2,000 more, and leaving about 200,000 homeless. Although the attacking force was smaller and dropped fewer bombs, there was no interception of the bombers by the Chinese Air Force whose airbases in the Chongqing region were not yet set up for nighttime operations.

Two months later, after tens of thousands of deaths, in retaliation for firebombing, the United States embargoed the export of airplane parts to Japan, thus imposing its first economic sanction against that nation.

The Japanese began to embark more nighttime bombing raids against Chongqing in summer of 1939 in an effort to reduce confrontation and casualties from defending Chinese Air Force fighters; however, the Chinese pilots began operating nighttime interceptions over Chongqing with some success in shooting down the nighttime bombers using "lone wolf" fighter tactics previously deployed during the Battle of Nanking two years earlier (and similar to the Wilde Sau tactics the Luftwaffe would deploy a few years later). The interceptions involved the coordination with a series of manually-operated ground based searchlights illuminating and tracking incoming bombers which can then be seen and targeted by the solitary fighter pilot; fighter ace Liu Zhesheng shot down a bomber on the night of 3 August 1939 flying "lone wolf" in an I-15bis during such a nighttime interception mission over Chongqing, among several other kills he claimed while battling for the defense of Chongqing. In the following night, Capt. Cen Zeliu would also claim a nighttime kill of a bomber while at the controls of an I-15bis.

"The Japanese bombers appeared over Chungking on moon-lit nights when they could easily see the major landmarks... from time to time, on command of their formation leader, all the bombers would open up a defensive barrage of fire in direction most likely of attack by fighters. The performance was effective. It was like a gigantic broom of fire sweeping the starry sky."    — K. Kokkinaki, Soviet pilot, witnessing the spectacle of night-time air-raids over Chongqing in 1939

Monks of the Ciyun Temple contributed greatly to rescuing and saving lives of residents over the course of the half-decade long bombing campaigns over Chongqing.

By mid-1940, the IJNAF G3M Model 21 bombers that formed the primary aircraft of the carpet-bombing campaign against Chongqing and Chengdu had become largely relegated to nighttime bombing attacks, while daylight raids were being replaced with the new and improved Model 22/23 G3Ms equipped with the higher-octane rated and supercharged Kinsei 51 engines, boosting the power of each of the twin-engined bombers by 500 horsepower and greatly enabling the schnellbomber strategy further above the general obsolescence of the defending Chinese fighter aircraft now struggling to gain speed and altitude to make even a single head-on pass against the high-speed/high-altitude IJNAF bombing runs, and even more vulnerable to the massed-firepower of those heavy bomber formations.

Also by mid-1940, the Japanese had employed new tactics to stave off attacks from defending Chinese fighters; the Chinese air raid early warning network would alert the Chinese fighter squadrons to scramble their fighters towards approaching Japanese bomber formations (ideally with ample time to attain sufficient altitude ahead of the raids); however, they were being monitored by fast IJNAF C5M (IJAAF designation Ki-15) scouting-attack planes at high altitudes which would radio instructions to the bombers to circle out of range as the Chinese fighters rose to meet the bombers; once the Chinese fighters had run low on fuel and returned to base, the scouts would then redirect the bombers to attack the Chinese fighters on the ground refueling. While the Chinese soon cracked the code used by the C5M crews relaying messages to the bomber formations, some of the countermeasures used by the Chinese pilots were to launch a pair of I-16s that were almost fast enough to intercept the C5M in pursuit, but enough to force the scouts away, while a second flight of fighters were launched against returning Japanese bombers as the first flight of Chinese interceptors returned to disperse in smaller auxiliary airbases to refuel, although successful interceptions were still limited against the IJNAF bombers as the Polikarpovs struggled in particular against the new Model 22/23 G3M bombers.

A C5M and three G3Ms were shot down over eastern Chongqing on 20 May 1940 by the 24th PS, the 4th PG equipped with the few (10 in total) 20mm ShVAK cannon-armed and more-powerful M-25V engined I-16 Type 17 fighters that the Chinese Air Force had; unfortunately, two of the I-16 Type 17s were put out of action following the battle, having been shot-up by the defensive fire from the Japanese raiders and making forced landings.

The Japanese air raids against Chongqing had become increasingly intense and destructive as the "joint air strike force" of the Imperial Japanese Army and Navy bomber formations began to comprise upwards of 150–200 bombers per raid, under the new codename "Operation 101", and massed defensive machine gun and cannon fire from the bomber formations were very effective against the slow Chinese fighter aircraft further handicapped with burning low-grade fuel, much of which came by way of French Indochina and processed locally; locally sourced oil came by way of the Yumen Laojunmiao oil wells in Gansu province beginning in the summer of 1939, which produced 90% of the native petrol (250,000 tons) for China during those war years.

The Japanese warned foreign delegations in Chongqing to avoid being hit as collateral damage in the massed attacks by moving to pre-defined "secure areas" which would be exempt from bombing; a large Nazi flag was emblazoned on the roof of the German embassy in Chongqing, but was still hit by a Japanese air raid.

Following the defeat of France by Germany in June 1940, the French Vichy Government submitted to the demands of the Japanese – allowing Japanese troops to conduct cross-border raids into Yunnan province, and the stationing of Japanese army air units at three airbases in French Indochina (now Vietnam), including Lạng Sơn.

On 10, 12 and 16 June 1940, the Japanese raided Chongqing with 129, 154 and 114 bombers on these days respectively, while the Chinese I-15 and I-16 fighter squadrons engaged these attacks shooting down 13 of the raiders, perhaps more importantly, forcing bombers to miss their targets, although these disrupted flights of bombers may have evaded the Chinese fighters from their primary targets, and diverted out to drop bombs on secondary targets, including other large population and industrial areas such as Ziliujing and Luxian. The Chinese would be dealt with a serious blow a few weeks later in July 1940 when the British yielded to Japanese diplomatic pressure and closed the Burma Road, which was China's primary lifeline for material and fuel needed in the defense of Chongqing and Chengdu.

On 11 August 1940, 4th PG CO Maj. Zheng Shaoyu personally selected a team of five of his top fighter pilots, including ace fighter pilot Capt. Liu Zhesheng and future ace Lt. Gao Youxin to deploy a new weapon in an experiment to help with the dispersal of, and attacks against, the massive Japanese bomber formations: multiple air burst bombs developed by combat flight instructor Yan Lei of the Central Air Force Academy at the Wujiaba Airbase. At 13:56 hours that day, 90 G3M bombers appeared in two waves, and Maj. Zheng's team, with ample preparations, maneuvered high and above the approaching bomber formation with precision flying while the Japanese aircrews observed the unusual movements of the Chinese fighters, who soon dropped the air-burst devices that descended under parachutes, and detonating just a few hundred meters in front of the lead bombers, resulting in a breakup of the bomber formation followed by furious attacks from the Chinese fighter pilots the best they could with the handicap of the highly challenged performance and firepower of their Polikarpovs, claiming five shot down (two wrecks confirmed) and damaging many others; eight Chinese fighters suffered various degrees of damage while the wreckages of Japanese bombers were found in Shichuxian and Shuangqing with three of the seven-man crew in one of the bombers found alive and taken prisoner.

The state-of-the-art new Japanese Mitsubishi A6M Zero fighters were first deployed into combat in course of the Chongqing and Chengdu bombing raids, and received its first baptism of fire in aerial combat on 13 September 1940; 13 Zeroes of the 12th Kokutai led by Lieutenant Saburo Shindo which had escorted 27 G3M bombers on a raid into Chongqing were sent against 34 Chinese fighters: including Polikarpov I-15bis (led by Maj. Louie Yim-qun of the 28th PS) and I-16 (led by Capt. Yang Mengjing of the 24th PS) and other Polikarpov fighters of Maj. Zheng Shaoyu's 4th PG. The battle lasted about half an hour by which point the Chinese were low on fuel and had to break off; with some luck, escaping further contact with the much faster Zeroes. Many of the Polikarpovs were damaged or shot down (the Zero pilots claiming 27 Polikarpovs shot down), with ten pilots killed, and eight wounded, Maj. Zheng Shaoyu and Lt. Gao Youxin managed to drive Zeroes off the tails of other Chinese fighters, with Lt. Gao closing-in to 50 meters (160 ft) of one, and claiming a Zero shot-down, but in fact only four Zeroes suffered some damage, and all 13 safely returned to base in Wuhan.

As the already desperate situation was now irrefutable with the scourge of the new Zero fighters, the Chinese Air Force high-command issued an all-points bulletin to avoid combat engagement against the new air-superiority fighters; however, Chinese fighters would continue with fatalistic courage to face the Zero on numerous occasions, including another large-scale dogfight over Chengdu on 14 March 1941 that saw the Japanese Zero fighters employ new tactics to avoid near-deadly mistakes from the 13 September 1940 air battle experience; the intense dogfight over Chengdu was another devastatingly dark day in the tragic chapters of the Chinese Air Force in the war, as eight pilots were killed, including top-ace fighter pilots Maj. John Huang Xinrui and Capt. Cen Zeliu, along with the young 2nd Lt. Lin Heng (younger brother of renowned architect Phyllis Lin Huiyin).

In response to the Japanese invasion of French Indochina, the Empire of Japan was finally met with the U.S. scrap metal and oil embargo against Japan and the freezing of Japanese assets in summer of 1941.

On 5 June 1941, in midst of the increased brutality of the new Operation 102 bombing campaign to force the Chinese to capitulate in their war of resistance, the Japanese flew more than 20 sorties, bombing the city for three hours. About 4,000 residents who hid in a tunnel were asphyxiated. With the start of full-scale war between the Soviet Union and Nazi Germany on 22 June 1941, and with Generalissimo Chiang Kai-shek looking for increased support from the Americans through the Lend-Lease Act of which was extended to China on 6 May 1941, all new fighter aircraft produced by the Soviets were now directed to the battlefronts against Nazi Germany.

On 11 August 1941, in what would be the last-recorded dogfight between the Chinese Air Force fighters and the IJNAF Zeroes before all active Zero squadrons were pulled out of China in preparations for Operation Z (the Pearl Harbor attack mission), future Japanese ace-fighter pilots Gitaro Miyazaki and Saburō Sakai were part of the escort of an Operation 102 bomber attack and fighter sweep of Chinese air bases between Chongqing and Chengdu, and encountered Chinese I-153 and I-16 fighters at Wenjiang Airbase; while shooting down all those that managed to take off or strafing those still taxiing down the runways, Saburo Sakai described how five Zeroes then struggled to shoot down the one last opponent still in the air that "was an absolute master" as it "snap-rolled, spiralled, looped and turned through seemingly impossible maneuvers... like a wraith", but Sakai himself only managed to finally shoot down the acrobatic biplane fighter pilot when he was forced to slow-roll in a climb while trying to clear over the top of a hill west of Chengdu. The belly of the Chinese fighter suddenly exposed right into the gunsight of Sakai's Zero, who fired cannon shells that "tore through the floorboards of the biplane", sending it down in a wide spin and exploding as it hit the hillside. Four Chinese pilots were killed in this engagement, including Lt. Huang Rongfa, whose fiancée, Ms. Yang Quanfang, took a pistol and shot herself at the memorial for him and the other martyrs on the 16th of August; under these special circumstances, the remains of Ms. Yang and Lt. Huang were buried together at the Chongqing Nanshan Air Force Martyrs Memorial Park.

On 30 August 1941, Lt. General Saburo Endo, commander of the Imperial Japanese Army's 3rd Sentai, having already received intelligence reports regarding an upcoming military conference in Chongqing held by Generalissimo Chiang Kai-shek, and the precise location for it, led a massive strike from Wuhan consisting of 205 bomber-attack planes, with Saburo Endo himself personally leading the assassination strike on Yunxiu Villa (specifically the Yunxiu Tower); at first, it made a low-level bombing run for accuracy, but was severely hampered by intense bursts of anti-aircraft fire that, according to him, "knocked me up away from my seat several times", and then having to increase altitude to 5,500 meters to make the bombing run instead, killing two guards west of Yunxiu Tower, but failing to kill the Generalissimo, who recorded in his diary how he felt the immense shocks of the bombing and suffering of the people who experienced the torment not just day and night, but for over four years.

Following the Japanese attack on Pearl Harbor in December 1941, the United States declared war on Japan, and President Roosevelt sought an immediate counterattack for the humiliation of Pearl Harbor; in the urgency to keep China resupplied for the new Sino-US joint effort in the war against Japan, General Joseph Stilwell was sent to Generalissimo Chiang Kai-shek on a top secret arrangement for the transfer of North American B-25 Mitchell bomber support equipment, radio-homing navigational aids and 100-octane avgas into China to support the planning of what was to become the Doolittle Raid against the Japanese home islands. The badly needed high-octane avgas and new equipment in China for the renewed war effort against the Empire of Japan were now increasingly being freighted via the risky Himalayan air-route known as "The Hump". As Japan's focus shifted towards the Pacific campaign, and much of the Japanese aerial-combat assets and experienced personnel had been diverted to support the war in the Pacific, the offensive campaign against Chongqing and Chengdu had been significantly curtailed; nonetheless, modern interceptor aircraft possessing far greater speed and firepower, supported by ground-based radar equipment, and new aircrew training supported by the US and Allied partners, allowed the Chinese Air Force to be in a much better position to fight back by August 1943. The last recorded air raid of the campaign took place on 19 December 1944.

Total Bomb Tonnage and Raids

Three thousand tons of bombs were dropped on the city from 1939 to 1942. According to photographer Carl Mydans, the spring 1941 bombings were at the time "the most destructive shelling ever made on a city", although terror bombing grew rapidly during the Second World War: by comparison 2,300 tons of bombs were dropped by Allied bombers on Berlin in a single night during the Battle of Berlin. A total of 268 air raids were conducted against Chongqing.

Lawsuit Against the Japanese Government

In March 2006, 40 Chinese who were wounded or lost family members during the bombings sued the Japanese government, demanding 10,000,000 yen (628,973 yuan) each, and asked for apologies. "By filing a lawsuit, we want the Japanese people to know about Chongqing bombings," said a victim. In 2006, 188 Chongqing bombing survivors filed a group lawsuit in Japanese courts, seeking compensation and an apology. In 2015 the Tokyo High Court upheld a lower courts' ruling acknowledging damages caused, but denying the plaintiffs' right to compensation.

References

Cheung, Raymond. Osprey Aircraft of the Aces 126: Aces of the Republic of China Air Force. Oxford: Osprey Publishing, 2015.

Caidin, Martin. Zero Fighter: Ballantine's Illustrated History of World War II Weapons Book No. 9. New York, NY: Ballantine Books Inc, 1969.

Xú,Lùméi.Fallen: A Decryption of 682 Air Force Heroes of The War of Resistance-WWII and Their Martyrdom 东城区, 北京, 中国: 团结出版社, 2016.

Japanese air raids drove mobs of Chinese into Chungking’s cave shelters.

Fighter pilot Xu Jixiang of the 17th Pursuit Squadron, 5th Pursuit Group leaning on an I-15bis, the plane he flew against the A6M Zero's debut air battle on 13 September 1940, fighting off numerous attacks by the confounding performance of the new air superiority fighter, and surviving; Xu would exact a measure of personal revenge on 4 March 1944 when he shot down an A6M Zero over the Japanese airbase at Qiongshan, Hainan, whilst flying a P-40 Warhawk with the CACW.

Japanese bomber crew preparing bombs before a mission in Hunan Province, China, 8 Sep 1944; bomb on right of photo noted 'gift for Chiang Kaishek'.

A photograph taken by IJA reporters on 16 June 1940 and published in the Asahi Shimbun showing bombs from IJAAF Type 97/Ki-21 heavy bombers exploding on Yuzhong Peninsula.

The vastly improved IJNAF Type 96/G3M Model 22 placed the defending Chinese fighter aircraft, and anti-aircraft artillery at an even greater disadvantage.

Large German flag painted on the roof of the German embassy in Chongqing, China to alert against Japanese bombers, circa 1939.

Beginning on 3 May 1939, Japanese bombers pulverize Chungking, China, Chiang Kai-shek’s capital since 1938, from the air.

Smoke and debris rising from the city, a result of savage air bombing by the Japanese.

Smoke rising from the many bamboo structures of the city, a result of savage air bombing by the Japanese.

Chongqing street after a 1941 Japanese bombing raid.

Bomb-damaged Chongqing, China, date unknown.

Casualties of a Japanese air raid, in which 4,000 people were trampled or suffocated to death trying to return to shelters. Chongqing, China, June 5, 1941.

Lt. General Saburo Endo who represented the Imperial Japanese Army Air Service during the Operation 101 and 102 joint-strike bombing campaigns, led a targeted aerial-assassination strike on Generalissimo Chiang Kai-shek on 30 August 1941; he would put forth his "Futility of the Chongqing Bombing Thesis" days after the failed assassination strike, and gained a reputation as a post-war anti-war pacifist, establishing the China-Japan Servicemen's Devotion Society.

Volunteer army leaving Chongqing.

Map showing the concentrated bombing of Yuzhong Peninsula in central Chongqing, by Imperial Japan during World War II (Second Sino-Japanese War).

Yokosuka B4Y Navy Type 96 Carrier Attack Bomber "Jean"

Yokosuka B4Y1 Type 96 (“135”) Imperial Japanese Navy.


The Yokosuka B4Y (Navy Type 96 Carrier Attack Bomber) was a carrier-borne torpedo bomber used by the Imperial Japanese Navy Air Service from 1936 to 1943. The B4Y replaced the Mitsubishi B2M2 and the Yokosuka B3Y, and was the last biplane bomber used operationally by the Imperial Japanese Navy. The Allied reporting name was "Jean". This aircraft was mistakenly identified by the British as the Nakajima Navy G-96.

In 1932, the Imperial Japanese Navy issued a requirement for a new carrier-borne attack aircraft. Aichi, Mitsubishi and Nakajima responded to this requirement and each built a prototype. None of these aircraft were deemed satisfactory, and the service thus issued in 1934 a new requirement, 9-Shi, for a more capable aircraft to replace the obsolescent Yokosuka B3Y. 

The B4Y was designed by Sanae Kawasaki at the First Naval Air Technical Arsenal at Yokosuka. Regarded only as an interim type, the Navy wanted a torpedo bomber offering performance comparable to the Mitsubishi A5M monoplane fighter. The result was a biplane with fixed landing gear and an all-metal structure with metal or fabric skin. To speed development and production, the B4Y utilised the wings from the Kawanishi E7K. The B4Y1 was also the first Navy carrier attack aircraft to utilize an air-cooled engine, as the prototype that was equipped with the Nakajima Hikari 2 radial engine performed better than its competitors.

The crew of three occupied two cockpits. The pilot in the open front cockpit and the other two crewmen, (navigator and radio operator/gunner), in the enclosed rear cockpit. 

On 12 December 1937 3 B4Y1s were involved in the Panay incident during a Japanese attack on the United States Navy gunboat Panay while she was anchored in the Yangtze River outside of Nanjing.

Although primarily used as a carrier-based aircraft, the B4Y1 was also used as a land-based bomber on occasion. In 1940, the Nakajima B5N replaced the B4Y1 as the primary carrier attack aircraft, though the B4Y1 did remain in service as an advanced trainer, and flew from Hōshō and Unyō until 1943.

Before its replacement, the B4Y1 had flown during the Second Sino-Japanese War and served at the Battle of Midway during June 1942, where eight of them were operated from Hōshō. It was one of these planes from Hōshō which took photographs of the burning Hiryū on 5 June 1942. 

Variants

First prototype: 559 kW (750 hp) Hiro Type 91 520 hp water-cooled W-12 driving a two-bladed propeller. 

Second and third prototypes: 477 kW (640 hp) Nakajima Kotobuki 3 nine-cylinder air-cooled radial driving a two-bladed propeller.

Fourth and fifth prototype and production aircraft: 636 kW (853 hp) Nakajima Hikari 2 nine-cylinder air-cooled radial driving a two-bladed propeller.

Production

First Naval Air Technical Arsenal, Yokosuka: 5 prototypes (1935–36)

Nakajima Aircraft Company: 37 production aircraft (1937–38)

Mitsubishi Heavy Industries, Nagoya: 135 production aircraft (1937–38)

11th Naval Air Arsenal, Hiro: 28 production aircraft (1938

Total: 205 aircraft

B4Y1.

Yokosuka B4Y.

An Imperial Japanese Navy Type 96 carrier attack plane flies near the aircraft carrier Kaga off China during the China incident in 1937 or 1938.




Mitsubishi J2M Raiden "Jack"

Mitsubishi J2M Raiden (“Lightning Bolt”).

 

The Mitsubishi J2M Raiden ("Lightning Bolt") is a single-engined land-based fighter aircraft used by the Imperial Japanese Navy Air Service in World War II. The Allied reporting name was "Jack". 

This is another design by vaunted designer Jiro Horikoshi, who was the subject of Hayao Miyazaki’s controversial animated feature film “The Wind Rises” (2013). Engine problems and coming along too late in the conflict made it less successful than Horikoshi’s more famous design - the A6M Zero.

The J2M was designed by Jiro Horikoshi, creator of the Mitsubishi A6M Zero, to meet the 14-Shi (14th year of the Showa reign, or 1939 in the Western calendar) official specification. It was to be a strictly local-defense interceptor, intended to counter the threat of high-altitude bomber raids, and thus relied on speed, climb performance, and armament at the expense of maneuverability. The J2M was a sleek, but stubby craft with its oversized Mitsubishi Kasei engine buried behind a long cowling, cooled by an intake fan and connected to the propeller with an extension shaft.

Teething development problems stemming from the engine cooling system, and the main undercarriage members led to a slowdown in production. A continual set of modifications resulted in new variants being introduced with the ultimate high-altitude variant, the J2M4 Model 34 flying for the first time in August 1944. It had a 1,420 hp Kasei 23c engine equipped with a turbocharger (mounted in the side of the fuselage just behind the engine) that allowed the rated power to be maintained up to 9,100 m (29,900 ft). Two upward-aimed, oblique-firing (aimed at seventy degrees) 20 mm cannons, mounted in the German Schräge Musik style, were fitted behind the cockpit with the four wing cannons retained. Unresolved difficulties with the turbocharger caused the project to be terminated after only two experimental J2M4s were built. 

The first few produced J2M2s were delivered to the development units in December 1942 but severe problems were encountered with the engines. Trials and improvements took almost a year and the first batch of the serial built J2M2 Model 11 was delivered to 381st Kōkūtai in December 1943. Parallel with the J2M2, production of the J2M3 Raiden Model 21 started. The first J2M3s appeared in October 1943 but deliveries to combat units started at the beginning of February 1944.

The Raiden made its combat debut in June 1944 during the Battle of the Philippine Sea. Several J2Ms operated from Guam and Saipan and a small number of aircraft were deployed to the Philippines. Later, some J2Ms were based in Japanese airfields in Korea under Genzan Ku: Genzan (Wonsan); Ranan (Nanam); Funei (Nuren); Rashin (Najin); and Konan, for defense of these areas and fighting against Soviet Naval Aviation units.

Primarily designed to defend against the Boeing B-29 Superfortress heavy bomber, the type was handicapped at high altitude by the lack of a turbocharger. However, its four-cannon armament supplied effective firepower and the use of dive and zoom tactics allowed it to score occasionally.

Insufficient numbers and the American switch to night bombing in March 1945 limited its effectiveness.

J2Ms took part in one of the final aerial combats of the Second World War when four Raidens, accompanied by eight Mitsubishi A6M Zeros, all belonging to the 302nd Kokutai, intercepted a formation of US Navy Grumman F6F Hellcats from the aircraft-carrier USS Yorktown during the morning of 15 August 1945 over the Kanto Plain. In the engagement, that took place only two hours before Japan officially announced its surrender, four Hellcats were lost along with two Raidens and two Zeros.

U.S. Technical Air Intelligence Command (TAIC) tested two captured J2Ms using 92 octane fuel plus methanol and calculated maximum speeds using measurements. The J2M2 ("Jack 11") achieved a speed of 407 mph (655 km/h) at 17,400 ft (5,300 m), and the J2M3 ("Jack 21") achieved a speed of 417 mph (671 km/h) at 16,600 ft (5,100 m).

Type: Fighter aircraft

Manufacturer: Mitsubishi Heavy Industries

Primary user: Imperial Japanese Navy

Number built: 621

Introduction date: December 1942

First flight: 20 March 1942

Retired: August 1945 

Specifications (J2M3)

Crew: 1

Length: 9.945 m (32 ft 8 in)

Wingspan: 10.8 m (35 ft 5 in)

Height: 3.81 m (12 ft 6 in)

Wing area: 20.05 m2 (215.8 sq ft)

Empty weight: 2,839 kg (6,259 lb)

Gross weight: 3,211 kg (7,079 lb)

Powerplant: 

1 × Mitsubishi MK4R-A Kasei 23a 14-cylinder air-cooled radial piston engine, 1,300 kW (1,800 hp) for take-off

1,174 kW (1,575 hp) at 1,800 m (5,900 ft)

1,051 kW (1,410 hp) at 4,800 m (15,700 ft)

Propellers: 4-bladed constant-speed metal propeller

Maximum speed: 587 km/h (365 mph, 317 kn) at 5,300 m (17,400 ft)

Cruise speed: 351 km/h (218 mph, 190 kn)

Range: 1,898 km (1,179 mi, 1,025 nmi)

Service ceiling: 11,700 m (38,400 ft)

Time to altitude: 6,000 m (20,000 ft) in 6 minutes 14 seconds

Wing loading: 171.3 kg/m2 (35.1 lb/sq ft)

Power/mass: 0.391 kW/kg (0.238 hp/lb)

Armament: 

2x 20 mm (0.787 in) Type 99 Mark 2 machine gun inboard wing-mounted with 190 rpg

2x Type 99 Mark 1 machine gun outboard wing-mounted with 210 rpg

2× 60 kg (132 lb) bombs

or

2 × 200 L (53 US gal; 44 imp gal) drop tanks or a larger central drop tank

Variants

J2M1 Prototype: fitted with the 1,044 kW (1,400 hp) Mitsubishi MK4C Kasei 13 14-cylinder air-cooled radial engine, and armed with two 7.7 mm (.303 in) Type 97 machine guns in the upper fuselage and two wing-mounted 20 mm Type 99 Model II cannon. Eight built.

J2M2 Model 11: Powered by 1,379 kW (1,850 hp) Mitsubishi MK4R-A Kasei 23a 14-cylinder radial engine, same armament as the J2M1.

J2M3 Model 21: Armed with two wing-mounted 20 mm Type 99 Model II cannon and two wing-mounted 20 mm Type 99 Model I cannon.

J2M3a Model 21A: Armed with four wing-mounted 20 mm Type 99 Model II cannon.

J2M4 Model 32: Prototype fitted with the 1,357 kW (1,820 hp) Mitsubishi MK4R-C Kasei 23c engine. Many armament configurations have been reported, e.g., fuselage-mounted oblique-firing 20 mm Type 99 Model I cannon designed to fire upward as it passed underneath a bomber, two wing-mounted 20 mm Type 99 Model II cannon, and two wing-mounted 20 mm Type 99 Model I cannon. Problems with turbocharger; only two experimental versions were built.

J2M5 Model 33: High altitude variant powered by 1,357 kW (1,820 hp) Mitsubishi MK4U-A Kasei 26a engine with mechanically driven supercharger, giving increased high-altitude speed at the expense of range. Two 20 mm Type 99 cannon in fuselage, two 20 mm Type 99 Model II cannon in wings.

J2M5a Model 33A: Armed with four wing-mounted 20 mm Type 99 Model II cannon. Wing cannon were harmonized in trajectory and ballistics with each having 200 rounds per gun.

J2M6 Model 31: Chronologically earlier than J2M4 and J2M5 this version was based on J2M3. Had wider cockpit and improved bubble canopy later used in J2M3 built since July 1943.

J2M6a Model 31A: Chronologically earlier than J2M4 and J2M5 this version was based on J2M3a. Had wider cockpit and improved bubble canopy later used in J2M3a built since July 1943. One J2M6a was built.

J2M7 Model 23A: J2M3 powered by Kasei 26a engine, a few built.

J2M7a Model 23A: J2M3a powered by Kasei 26a engine, a few built.

Production

After the decisive Battle of Midway in 1942 Japan's military leaders rushed to re-equip their forces for defense of the home islands. In fighter designs the interceptor role now took priority over forward projection of offensive power. Allied forces, meanwhile, sought to establish air superiority over Japanese-held territories via B-29 bombing raids on industrial targets.

The struggle to meet production demands sparked a Japanese initiative to recruit shonenko (child labor) from Taiwan (Formosa). Though the target of 25,000 youths was never reached, over 8,400 Taiwanese youths aged 12 to 14 relocated to Mitsubishi plants to help build the J2M Raiden.

The Allied advance took its toll. In 1945 aircraft production in Japan collapsed.

Allied bombing raids of Nagoya began in December 1944 and progressively disrupted production of the J2M. A direct hit on the Mitsubishi Dai San Kokuki Seisakusho aircraft plant caused the complete loss of airframes, machine tools, and jigs. This halted further production.

Production generally suffered less from direct hits on factories, which were rare, but from attacks on suppliers and consequent shortages of material and construction tools.

Operators 

Japan

Imperial Japanese Navy Air Service

Surviving Aircraft 

J2M3 Model 21 c/n 3014 is on display at the Planes of Fame Air Museum in Chino, California. It was brought from Japan in 1945 for technical evaluation by the US Navy. Later declared surplus, it was displayed at the Travel Town Museum in Griffith Park, Los Angeles before it was acquired in 1958 by Planes of Fame founder Edward T. Maloney.

Bibliography 

The Complete Encyclopedia of World Aircraft New York: Barnes & Noble, 1977.

Francillon, René J. (1979). Japanese aircraft of the Pacific War. London: Putnam (new edition 1987 by Putnam Aeronautical Books).

Green, William. Air Enthusiast Magazine, Quarterly Volume 1, Number 2 Bromley, Kent: Pilot Press, 1971.

Green, William. Warplanes of the Second World War, Volume Three: Fighters. London: Macdonald & Co. (Publishers) Ltd., 1973, First edition 1961.

Huggins, Mark (January–February 2004). "Hunters over Tokyo: The JNAF's Air Defence of Japan 1944–1945". Air Enthusiast (109): 66–71.

Izawa, Yasuho & Holmes, Tony. J2M Raiden and N1K1/2 Shiden/Shiden-Kai Aces. Osprey Publishing. 2016 Aircraft of the Aces Number 129.

Ledet, Michel & Osuo, Katshuhiko (January 2001). "Mitsubishi J2M Raiden: l'intercepteur de la Marine japonaise" [Mitsubishi J2M Raiden: The Japanese Navy's Interceptor]. Avions: Toute l'Aéronautique et son histoire (in French) (94): 8–16.

Ledet, Michel & Osuo, Katshuhiko (February 2001). "Mitsubishi J2M Raiden: l'intercepteur de la Marine japonaise". Avions: Toute l'Aéronautique et son histoire (in French) (95): 20–28.

United States Strategic Bombing Survey Aircraft Division. Mitsubishi Heavy Industries, Ltd. Corporation Report I, Washington, D.C. 1947.

United States Strategic Bombing Survey Aircraft Division. Army Air Arsenal and Navy Air Depots Corporation Report XIX, Washington, D.C. 1947.

 

December 1945: Japanese aircraft taken over by the Allies in British Malaya were tested and evaluated by Japanese naval aviators under close supervision of RAF officers from Seletar Airfield. Here two Mitsubishi J2M Raiden fighters (known to the Allies as 'Jack'), belonging to the 381 Kokutai of Imperial Japanese Navy Air Service, are flying in close formation during their evaluation flight.

A J2M3 Model 21 in the Planes of Fame.

Mitsubishi J2M.

April 21, 1945: Mitsubishi J2M-3 Raiden fighter ("Jack") in USAAC markings, of the South West Pacific area technical air intelligence unit.

Surrender of Japan, August-September 1945. Japanese planes at a Tokyo Airfield, Japan. Photograph received September 21, 1945.

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 (SWPA) located at Clark Field, Luzon (Philippines) from the end of January 1945. The aircraft was recovered from a makeshift airstrip in Manila when American forces recaptured the city. Other aircraft in the formation are a Royal Navy Seafire (lower left) and a U.S. Navy Grumman F6F-5 Hellcat. The Mitsubishi J2M's development to full combat status was delayed by technical problems and production indecision, resulting in employment being mainly in the defence of Japan from USAAF bombing.

December 1945:  Japanese aircraft taken over by the Allies in British Malaya were tested and evaluated by Japanese naval pilots under the supervision of Royal Air Force officers. Here a Mitsubishi J2M Raiden (known to the Allies as a 'Jack'), belonging to the 381 Kokutai of Imperial Japanese Navy Air Service, has its engine run prior to flight whilst Japanese ground crew wait in attendance at RAF Seletar.

December 1945: Japanese aircraft taken over by the Allies in Malaya were tested and evaluated by Japanese naval pilots under the supervision of Royal Air Force officers. Here Japanese ground crew watch one of their aircraft. Behind them stands a Mitsubishi J2M Raiden (known to the Allies as a 'Jack').

 Over the Philippines, a Japanese Navy interceptor fighter aircraft Mitsubishi J2M Raiden (Thunderbolt, allied code name "Jack") in flight, of the Technical Air Intelligence Unit, South West Pacific Area (SWPA) located at Clark Field, Luzon (Philippines) from the end of January 1945. The aircraft was recovered from a makeshift airstrip in Manila when American forces recaptured the city. The Mitsubishi J2M's development to full combat status was delayed by technical problems and production indecision, resulting in employment being mainly in the defense of Japan from USAAF bombing.

1943: Prototype Mitsubishi J2M3 Raiden 21 from Yokosuka Naval Air Technical Arsenal testing unit. 

Third production J2M1.

J2M3.

J2M3a Raiden 21a, 302nd Air Corps, operating in the defense of Yokosuka.

J2M3a, 302nd Air Corps, operating in the defense of Yokosuka.

Three-view drawing of J2M3. Starboard side view at top is J2M4.