On 7 July 1937 a military clash between Japanese Army and Chinese Army units broke out near Beijing (Peking), while early in August a Japanese Marine officer was killed in Shanghai. These incidents were employed as ‘Cause célèbres’ to allow what rapidly became a full-scale war to develop between the two countries which would last until 1945. Nevertheless, it remained known to the Japanese as ‘The China Incident’ throughout its course.
Available as the ‘incident’ broke out, a number of new Kokutais had been recently formed within existing Kokutais. At Saeki Kokutai in Kyushu the 12th Kokutai, equipped with 12 Type 95 fighters, 12 dive-bombers and 12 torpedo aircraft was formed, while at Ohmura Kokutai – also located in Kyushu – the 13th Kokutai also came into existence with 12 new Type 96 Fighters, six dive-bombers and torpedo aircraft.
Thus at the start of the incident, the IJN had available to take part some 84 carrier aircraft, 118 land-based aircraft and 62 floatplanes (including those on ships of the 3rd Fleet). This represented some 65% of the service’s 408 first-line machines at the time.
An inter-air force agreement was reached with the Japanese Army on 11 July 1937, whereby the IJN would be responsible for aerial operations over central China. In mid August the carriers Kaga, Hosho and Ryujo were despatched to Shanghai. Kaga carried 16 Type 90 fighters, 14 dive-bombers and 22 torpedo-bombers; Hosho and Ryujo each had aboard 21 Type 90 fighters, 12 dive-bombers and nine torpedo-bombers.
As the IJN prepared for an initial strike on Chinese airfields and other targets on 14 August, a typhoon struck the ships offshore, preventing take-off. This allowed the Chinese to strike first, a force of about 40 fighters and bombers attacking the vessels and the Japanese Marine Headquarters in Shanghai. In the conditions prevailing only the single floatplanes from the cruiser Izumo and the light cruiser Sendai managed to get off, claiming victories over a Curtiss Hawk biplane fighter and a Northrop single-engined bomber. Fortuitously for the Japanese, aerial combat had become one of the items taught to two-seat floatplane crews since 1932, and such aircraft would frequently be launched to intercept incoming raiders.
Two days later on 16 August, another crew from Izumo claimed a Hawk destroyed, while on 21st six floatplane crews claimed six, suffering only damage to one of their number – although this was of a fairly serious nature. On 2 September three floatplanes engaged nine Curtiss Hawks, claiming three shot down and one forced down for a loss of a single floatplane. However, as these aircraft were also engaged in bombing and reconnaissance, their rate of attrition was rather high, 25% of the aircraft available and 7% of the crews being lost during a period of just one month. No floatplane aces were produced during the China Incident, but aircraft of this type had gained a good number of early victories. As a result, the idea began to be adopted that float fighters were an inexpensive and speedy expedient which allowed the creation of a floatplane base, rather than having to construct a front line airfield.
With an improvement in the weather, operations by the carrier-based air groups soon got underway, and on 16 August six of Kaga’s Type 90 fighters led by Lt Chikamasa Igarashi encountered four Chinese fighters, claiming three of them shot down over Jiangwan, Shanghai. Next day four more such aircraft led by Wt Off Mitsuo Toyoda claimed two further successes. At the end of the month the first of the new Type 96 monoplanes arrived by carrier from the homeland, and on 4 September Lt Tadashi Nakajima led two of these to their first victories, claiming three Curtiss Hawks shot down. On 7 September Lt Igarashi, now flying one of the new aircraft, led his flight of three to claim five victories over Taihu, three of which were credited to Igarashi personally.
Meanwhile the other carrier air groups had also been piling up successes. Lt Tadashi Kaneko leading four Type 90 fighters from Ryujo spotted 18 Curtiss Hawks over Baoshan on 22 August and ‘bounced’ these, he and his pilots claiming six without any of their aircaft suffering a single hit in return. Next day four more Ryujo fighters led by Lt(jg) Minoru Suzuki took on 27 fighters in the same area, and despite their numerical inferiority, claimed nine for no loss, three of them by Suzuki. The Hosho fighters were less fortunate in finding opponents. Their only success during this initial period amounted to a single twin-engined Martin monoplane bomber, shot down on 25 August by a trio of Type 90s led by Lt(jg) Harutoshi Okamoto.
Early in September Kunda airfield at Shanghai became available for use by the IJN, and at once the 12th Ku (12 Type 95 fighters, 12 Type 94 dive-bombers and 12 Type 92 torpedo-bombers) and the 13th Ku (12 Type 96 fighters, six Type 96 dive-bombers and six Type 96 torpedo-bombers) flew in. They were joined by six Type 90 fighters, six Type 96 fighters, 18 dive-bombers and 18 torpedo-bombers from Kaga.
In an effort to neutralise the Chinese fighters defending the Nanking area, Type 96 Fighters from Zhenru, Shanghai undertook 11 sweeps over Nanking between 19-25 September, accompanied by dive-bombers, torpedo-bombers and floatplanes. On 19th, the initial day of the attacks, 19 Type 96 fighters of the 13th Ku led by Lt Shichiro Yamashita, escorted 17 dive-bombers to the area, accompanied by 16 floatplanes. More than 20 intercepting fighters were encountered, the Type 96 pilots claiming 15 and three probables without loss while the floatplane crews claimed 12 for a single loss. By 25 September the IJN units had claimed a total of 42 destroyed and six probables. Following these raids, Kaga returned to Japan with its air group embarked.
Aircraft of the Chinese Air Force were now beginning to appear over southern China, and fearing that these might interfere with the Japanese naval blockade, or even launch attacks on Japanese bases in Formosa, attacks by Rikkos (medium bombers) were launched, while both Ryujo and Hosho took part in an attack on Canton on 21 September. Lt Cdr Yasuna Kozono, the Hikotai leader on Ryujo, led six fighters from each carrier to escort torpedo-bombers and dive-bombers to attack two airfields at Canton. Here the escorts engaged ten or more Curtiss Hawks, each unit claiming six shot down. However, during the return flight five Hosho fighters force-landed in the sea when they ran out of fuel; all the pilots were rescued safely by Japanese destroyers. A second attack followed, during which nine Ryujo fighters escorted the bombers, claiming five more shot down and one probable. Carrier aircraft were to launch further attacks on two following days, but encountered no opposition.
On land around Shanghai the situation became steadily more favourable to the Japanese despite overwhelming numerical odds. During November three Japanese infantry divisions landed in Hangchow Bay, south-west of Shanghai. The Japanese command now believed that if Nanking, the capital of China at that time, could be taken by the end of November, the ‘incident’ could be concluded satisfactorily. During this period the A5Ms (Type 96s) of the 13th Ku were regularly in action over the Nanking area. The commanding officer, Lt Yamashita, had been obliged to force-land in hostile territory and had become a prisoner of war, leadership of the unit being taken over by Lt Mochifumi Nango. On 12 October the unit’s pilots claimed five victories, while on 2 December six pilots fought more than 30 interceptors, claiming 13 shot down.
The 12th Ku, saw no action with its older A4Ns(Type 95s) at this time, becoming engaged in defensive patrols and ground support sorties as the unit began gradually to convert to the superior A5Ms. On 13 December Nanking fell to the Japanese, but far from giving up, the Chinese government fled to Hankow, determined to continue the war from there.