The ‘I-Go’ Operation

Admiral Isoroku Yamamoto, commander of Combined Fleet, transferred headquarters to Rabaul for Operation I-Go.

A2-2-152 was flown by a wingman of carrier Junyo.

2-1-202 was flown by a wingman of carrier Junyo. Solomon islands, during I-GO operation, April 1943. This plane shows two vertical red bands that means when Junyo was second carrier of 2nd division.
Beginning with the I-Go Operation in April 1943, photos indicate that the aircraft of either of the two carrier divisions assigned to temporary duty in the Solomon islands over painted both the A prefix in their tail codes and the fuselage vertical bands in some aircraft.


The Allies now possessed the initiative in New Guinea and among the Solomons. Their supremacy rested upon their air superiority, due not so much to the quality of material as to the tactics forced upon AirSols by the aggressive Japanese, whose losses in actual combat were far exceeded by the losses involved in all-weather flying at great ranges from their bases. While many American aviators were rescued, or were even able to regain their bases in damaged aircraft, damaged Japanese aircraft were less often able to return the 350 to 650 miles to Buin, Buka or Rabaul, and their chances of rescue after a forced landing were slim.


With the departure of the IJAAF fighters from Rabaul, only the IJNAF’s 11th Air Fleet remained to provide aircraft for the South-West Pacific area. The backbone of the force was made up by eighty-six A6Ms and seventy-two G4M ‘Bettys’, supported by lesser numbers of D3As and B5Ns. The Japanese Army had given up its offensive in New Guinea, but was now intending to stabilise a deteriorating situation by strengthening existing garrisons. At the same time, concern was felt about the American intentions out in the Solomons. To carry the necessary New Guinea movements and to check the Solomons build-up it was clear that temporary air superiority would have to be achieved over both areas. As the IJAAF Staff were intransigent over the matter of providing air units, the IJNAF would have to find aircraft from its own resources.


Only one source was immediately available. The Air Flotillas in the East Indies, Marianas and on Formosa had all had their most experienced personnel siphoned off for the 11th Air Fleet, and only the air groups of the First Carrier Division, Zuikaku, Shokaku and Zuiho, could provide a balanced reinforcement. The groups had been trained after the Battle of Santa Cruz and were only just attaining the level of expertise necessary to engage the American carriers, so that there was considerable opposition from the Combined Fleet (Admiral I. Yamamoto) and the Third Fleet (the operational carriers) commanded by Vice Admiral T. Ozawa, who had relieved Vice Admiral Nagumo in November 1942. The disaster in the Bismarck Sea forced the IJN to take the first fatal step at the end of March 1943, and by 1 April 161 A6Ms and D3As and a score of B5Ns had arrived at Rabaul, Buka, Ballale and Kahili. The dive-bombers and torpedo-bombers were on the Bougainville airfields to bring them within range of Guadalcanal, but the ‘Zeros’ had sufficient range to accompany the ‘Bettys’ all the way from Rabaul to the targets in New Guinea and the Solomons.


Operation PA, as the Solomons neutralisation was codenamed, started on 1 April 1943, with a sweep by fifty-eight A6Ms of the 11th Air Fleet. These aircraft were supposed to inflict maximum casualties upon any American fighters found airborne, but over the Russell Islands they were met by a mixed force of forty-one USMC F4F Wildcats, USAAF Lockheed P-38 Lightnings and USMC F4U-1 Corsairs, the last based at Henderson Field since mid-February. Only six of the defending fighters were lost, but Japanese losses from all causes amounted to eighteen, nearly a third of the force, while the returning pilots made extravagant claims.


The disembarked carrier aircraft were not ready for their first attack until 7 April, when eighty-nine fighters and forty-nine dive-bombers, reinforced by twenty-one fighters and eighteen dive-bombers of the 11th Air Fleet, rendezvoused over Kahili and made for Guadalcanal to attack shipping. The Japanese had chosen a good day for their strike, for there were some forty worthwhile targets in Lunga Roads. Coastwatchers gave ample warning of the approach of the raid, for three hours elapsed between the first report and the development of the attack, which was carried out in a series of waves.


Seventy-six American fighters intercepted, but of these only twenty went for the sixty-seven ‘Vals’, which, not surprisingly, broke through and attacked the ships. A Royal New Zealand Navy A/S trawler was sunk in Tulagi harbour, as were an oiler and a destroyer. The only other damage was to the hulk of a previous casualty, in use as a fuelling wharf. A dozen or so ‘Vals’ were shot down by fighters and the ships’ AA fire, as well as nine of the escorting A6Ms; the American fighters had claimed twenty-seven. The Japanese aircrew who returned overclaimed once again, to the extent that Admiral Yamamoto, who was directing the ‘I’ Operation, believed that the strike had achieved a major success, drawing the teeth of AirSols and weakening Allied merchant and warship potential for some while to come. In fact the fighters defending Lunga Roads had lost only seven of their number, and all but one of the pilots had been recovered.


With Guadalcanal neutralised to his satisfaction, Admiral Yamamoto switched his aircraft to the New Guinea combat zone. On 11, 12 and 14 April no fewer than 456 sorties were flown against Allied transports in Oro Bay, near Buna, and in Milne Bay, and against the Port Moresby airfields. These raids, four altogether, sank one ship and damaged five others: five USAAF and RAAF fighters were shot down, and the IJNAF lost eighteen aircraft. With air reports of a substantial victory, amounting to three warships and twenty-five transports sunk and many others damaged, and 175 Allied aircraft shot down, Admiral Yamamoto decided that the ‘I’ Operation had achieved its aim by 16 April, and it was terminated. A few days later the carrier air groups flew out to Truk, less the thirty aircraft lost during their five strikes. On 18 April, shortly before their departure, they had been standing by at Kahili awaiting a review by Admiral Yamamoto. The USN had learnt of this visit before the Japanese at Kahili, and with the USAAF achieved a masterpiece of intelligence gathering, planning and, literally, execution. Eighteeen P-38s of the 339th Fighter Squadron, USAAF, met Yamamoto’s ‘Betty’ and its escort a few miles short of Kahili and the chosen marksman, Captain Thomas Lanphier, destroyed not only the C-in-C’s aircraft, but also a second ‘Betty’ carrying members of his staff. The loss to the IJN was incalculable, for Admiral Yamamoto had been the only flag officer with experience and expertise enough to direct a holding campaign against the growing strength of the USN. Admiral M. Koga, his successor, was a competent commander, but he had had virtually no sea experience during the war so far, and as yet he was unable to command the respect which had been earned by Yamamoto. Morale was sagging, particularly in the Rabaul area, and his death occurred at an inopportune moment, with the Allies preparing for their next amphibious leap.


The use of CarDiv 1’s aircraft from shore bases had been moderately successful. The losses, some 15 per cent of the aircraft sent to the Solomons, had not been excessive in view of the results claimed. A precedent had been set for the use of carrier groups in land-based operations. The premises upon which subsequent deployments were based were false, and the Japanese carrier fleet’s effectiveness suffered accordingly.

New Georgia

On 17 May 1943 Admiral W. F. Halsey’s Third Fleet in the South-West Pacific was reinforced by the arrival of HMS Victorious and the battleship North Carolina. The carrier had been despatched from Pearl Harbor to join Saratoga in providing distant cover for the forthcoming invasion of New Georgia, a 160-mile leap forward from Guadalcanal, and one which was expected to be resisted bitterly by the enemy.


The Japanese had built airfields on New Georgia Island and Kolombangara Island towards the end of 1942, and IJNAF aircraft had been based there, to strike at Guadalcanal and to protect warships in the ‘Slot’. However, repeated attacks by AirSols had forced their withdrawal as a permanent force, and Munda and Vila airfields were used mainly for staging aircraft based at Rabaul, Buka and the Bougainville airfields. In April 1943, following the withdrawal of CarDiv 1’s aircraft, the IJAAF had been obliged to despatch more aircraft to the Solomons, about sixty in all, most of which were sent forward to Munda. Losses were made good to a very limited extent: replacements arrived at Truk in some numbers, but the extended flight from Truk to Rabaul led to some remarkable non-combat casualty statistics, particularly among the IJAAF aircrew. Up to April 1943 some 6 to 7 per cent of aircraft on ferry sorties failed to arrive, but thereafter the loss rate rose to about 25 per cent for IJNAF aircraft, and in June only two out of one flight of twenty-four IJAAF aircraft reached Rabaul.


At the beginning of June 1943 the IJNAF 11th Air Fleet and the IJAAF 4th Air Army possessed approximately 280 aircraft for operations, nearly 100 of which were G4Ms. On the 10th half-a-dozen of these ‘Bettys’ attacked a convoy bound for Guadalcanal to the southeast of the island. All important shipping movements to and from Guadalcanal had been accompanied by one or more of the escort carriers based on Noumea, and on this occasion Suwanee was in company. Good warning of the raid had been given by the coastwatchers, and the USMC Corsair patrols from Henderson Field shot down all six of the torpedo-bombers before they could close the CVE, their primary target. Aware of Allied interest in New Georgia, and that a major operation was forthcoming, the 11th Air Fleet made a determined attempt to destroy this convoy, first by a night torpedo attack on 10/11 June, and then at midday on 11th, as the ships were entering Lunga Roads. The night attack, by eighteen G4Ms, was evaded, the ships manouevring to force the aircraft to drop their torpedoes from unfavourable positions, and the day attack caused the loss of only one ship. Twenty-four bombers and up to seventy-two A6Ms took part in the daylight raid, and of the former only one returned to Rabaul. Further attacks during the month added nothing to the Allies’ casualty lists but cost the Japanese more aircraft than they could afford; 138 IJNAF aircraft were lost during the month, together with their crews. With a further forty IJAAF aircraft lost, and the high level of non-combat losses, further urgent reinforcements were required, over and above replacements.


For the second time the only source of reserve strength was the carrier fleet, the Third Fleet, and CarDiv 2 was selected to provide their air groups. Less well trained than those of CarDiv 1, they would still be superior to the inexperienced crews arriving as normal replacements. The move was delayed by the torpedoing of Hiyo, hit by one torpedo from the submarine Trigger during the night of 10/11 June. The attack took place fairly close to Yokosuka, a major naval dockyard, so that the problems of immediate salvage and repair were much simplified for the Japanese. Junyo and Ryuho had to embark Hiyo’s aircraft for delivery to Truk, and the short delay which was thus occasioned prevented the 150 A6Ms, D3As and B5Ns from arriving at Rabaul until the invasion of New Georgia was well under way.


For Operation Toenail, the New Georgia landings, Admiral Halsey’s naval forces included three CVEs and two fast carriers. These were to take no direct part in the assault, for with 258 fighters and fighter-bombers and 193 SBDs and TBFs AirSols had sufficient aircraft to provide fighter cover for the transports and the beach-heads, as well as close support and strikes on pre-briefed targets. In point of fact, the distance between the target area and the Russell Islands, the nearest fighter bases, was rather too great (175 miles) and imposed great strain on the pilots. A thirty-two-strong fighter patrol was programmed for daylight hours, for which ninety-six aircraft would be required out of the serviceable total of 213. Losses would reduce the pool required for strike escort and local defence tasks from Guadalcanal to New Georgia. Saratoga and Victorious possessed seventy-two F4F-4s and Martlet IVs (F4F-4Bs) between them, and there were another three dozen aboard the escort carriers. With deductions for self-defence the carriers could have provided another fifty to sixty aircraft for short periods, provided that they themselves were not attacked. The USN had no illusions of complete naval/air superiority, however, in spite of the enemy’s huge losses in June, and the carriers were held back, the fast carriers in company with three fast battleships to cover against an attempt by their Japanese opposite numbers against the invasion shipping. Sangamon, Suwanee and Chenango, with two old battleships, formed a reserve force whose main task was the protection of shipping between Espiritu Santo and Guadalcanal, but which could also fight a delaying action against a Japanese force attempting to break into the Coral Sea by the improbable eastern approach route.


The first landings on New Georgia took place at the eastern end of the island on 21 June 1943. Segi Point was unoccupied by the enemy, and work started on a fighter strip at the end of the month. By 11 July it was ready for emergency operations. No support, other than that of the destroyer-transports which had put the Marines ashore, was provided at Segi Point, and Task Group 36.3, the heavy covering force, did not sail from Noumea until 27 June.


Victorious and Saratoga had exercised together during the earlier part of the month, and, after assessing the particular tactical virtues of the Royal Navy carrier, Rear Admiral D. C. Ramsey, flying his flag in Saratoga, proposed a partial exchange of aircraft between the two ships. Victorious ability to operate the TBF-1 was marginal, in spite of recent modification at Pearl Harbor, but her fighter direction organisation was far superior to that of Saratoga. The advantages of each carrier being responsible for a single task were obvious, so all the TBFs of 832 Squadron were transferred to Saratoga, and twenty-four F4F-4s of the latter’s VF-3 joined the thirty-six Martlets of 882, 896 and 898 Squadrons aboard Victorious. The American carrier retained twelve Wildcats for strike escort and her own selfdefence. Planning, briefing and tactical co-ordination were thus much simplified, and the arrangement whereby one carrier was tasked with defence and the other with search and strike was near to the ideal. How effective the pair might have been in combat was never established, for although TG 36.3 remained at sea for 28 days during Toenail, the circumstances for its direct involvement did not arise.


Landings were made on Rendova Island and two small islands to the east of Munda on 30 June, the first assault on New Georgia Island itself being made on 2 July. Not until mid-afternoon on the first day did 11th Air Fleet aircraft press home an attack, when two dozen G4Ms attacked the transports in the Rendova anchorage, sinking the amphibious headquarters ship McCawley at the cost of all the aircraft which took part. An hour later a similar number of D3As appeared from Kahili, but these concentrated their attentions on the hulk of the HQ ship, scored no hits and lost heavily. Although A6Ms and a few IJAAF aircraft made hit-and-run attacks, these too achieved little at considerable cost.


The pattern was repeated on the next day (1 July), but after losing over sixty aircraft in the two days the Japanese were obliged to slacken their air effort until sufficient aircraft could be made serviceable for another onslaught. By the end of July the IJNAF had lost over 300 aircraft, in combat and through operational causes, during the ‘Munda campaign’.


The IJN faced another Guadalcanal-type problem. Supplies and reinforcements had to be brought from Rabaul and Bougainville in the face of strong Allied opposition, but without a carrier fleet strong enough to challenge the USN’s the scale of the earlier ‘Tokyo Express’ could not be repeated, even if the IJN had possessed sufficient destroyers for use as transports, and the heavy cruisers to cover them. Nevertheless, Japanese destroyers and landing barges did make a number of runs from Shortland Islands to New Georgia and Kolombangara, succeeding in passing undetected on the first occasion, but encountering opposition on four subsequent occasions. The Battles of Kula Gulf (6 July), Kolombangara (13 July), Vella Gulf (6/7 August) and Vella Lavella (17-18 August) in many ways repeated the pattern of battles around Savo Island during the last four months of 1942, with the Japanese destroyer torpedo’s long range inflicting casualties on opposing radar-equipped cruiser groups. The USN and RNZN, with considerable advantages in detection, communications and gunnery, lost one cruiser outright and another three badly damaged, as well as one destroyer sunk, while the Japanese lost an old light cruiser and four destroyers. Most of the troops carried were landed at or near their intended destinations.


AirSols attacked the Buin-Kahili-Shortlands assembly area for the reinforcement runs, TBFs and SBDs being supported by USAAF B-17s, B-24s and B-25s. Air support in the Munda area was provided by the naval and USMC attack aircraft, as many as 105 TBFs and SBDs taking part in a single raid. Strong fighter escorts were provided for the 130 strikes delivered during the five-week campaign, with up to 114 Corsairs, Wildcats, Lightnings and Curtiss P-40 Warhawks at a time to swamp the intercepting ‘Zeros’. Many Japanese warships and transport craft were damaged, including the heavy cruiser Kumano, and four destroyers and the seaplane carrier Nisshin were sunk by the strikes.


The CVEs covered their convoys without incident. The 11th Air Fleet was sufficiently occupied with events closer to Rabaul, and such submarines as were in the Solomons were being used as transports or to attempt the disruption of shipping around New Georgia. The covering position of TG 36.3 was 360 miles to the south of Guadalcanal (550 miles to the south of Munda at the western limit of the patrol line), but six sweeps were made to the north to within 250 miles of New Georgia. These pushes were preceded by TBF and SBD searches out to 230 miles from the carriers, and it was during one such sortie that the Task Group made its only contact with the enemy, an SBD of VB-3 sighting and attacking a G4M 60 miles to the northwest of the ships. The covering force returned to Noumea on 25 July. The Munda airfield had not yet been captured, but the beach-head was secure and it was clear that the main strength of the Japanese fleet was not going to be committed to the campaign.


The operations off New Georgia were the last extended carrier deployment during the Solomons campaign. Once the airfields at Segi Point and Munda had been developed, Rabaul was within comfortable fighter and dive-bomber range of AirSols. The US Fifth Air Force in New Guinea and Australia was already attacking in strength with its heavy and medium bombers. Japanese air and shipping losses continued to mount, and although the arrival of CarDiv 2’s 150 aircraft brought a temporary stiffening to the 11th Air Fleet in mid-August, this was counterbalanced by the complete withdrawal of the IJAAF component in the area. The occupation of Vella Lavella Island, between the New Georgia group and Bougainville, at the beginning of September provoked strong reaction from the 11th Air Fleet, as a result of which the Buin-based CarDiv 2 air groups suffered heavily and were forced to withdraw to Rabaul to re-form. During the same month Allied troops landed at Lae and Finschafen in New Guinea, and the remaining Japanese air effort had to be divided between the two fronts, with consequent heavy attrition. By early October 1943 it was clear that the last IJNAF reserves would have to be committed if the steady advance on Rabaul was to be checked, let alone stopped. CarDiv 2, Junyo and Ryuho, had been unable to train new air groups as they had been almost continuously engaged in ferrying replacement aircraft from the Home Islands to Truk since sending their own to Rabaul in early August, so CarDiv 1 was obliged to give up its trained crews for the second time in eight months. The IJN could have hardly chosen a less appropriate moment to emasculate its carrier force.

Japanese Army Air Force - China 1942

During early 1942, the enemy gradually strengthened its air forces in south China, especially around Hengyang and K'weilin. Also, aerial pictures taken by the 1st Air Brigade in late March showed that the runways on Chuhsien, Lishui and Yushan airfields had been increased from 700 meters to 1,500 meters; that ammunition and fuel were gradually being accumulated and that additional installations were being built. Furthermore, an airfield had been constructed at Chienou. This work was carried out under the protection of fighters that flew almost daily from Hengyang and Kweilin.

In early April, the 1st Air Brigade (using about 50 planes, including fighters and reconnaissance planes) attacked and destroyed a newly built enemy airfield in the Chekiang sector, destroying the runways and the majority of installations. Although the Brigade repeated these attacks again and again, each time the enemy succeeded in rebuilding the field.

Imperial General Headquarters foreseeing that airfields in the Chekiang area could be used to advantage by the enemy as terminals in raids against Japan from air bases and carriers in the Pacific, as well as from other bases on continental China, ordered the China Expeditionary Army to destroy enemy air bases in the Chekiang area.

On 16 April, Imperial General Headquarters drafted an operation-al plan, an extract from which read:

Objective: The primary mission will be to defeat the enemy in the Chekiang area and to destroy the air bases from which the enemy might conduct aerial raids on the Japanese Homeland.

It further stated that the new enemy airfields and their attach-ed installations were being skilfully camouflaged and decentralized and that they should be sought out and destroyed. On 20 April, a further directive was issued stating:

The Air Forces of the United States, Britain and China will seek bases in China from which to bomb Japan. They may also attempt to carryout air raids on Japan from Midway, Morell, the Aleutians and from aircraft carriers, in which event the logical terminal would be airfields in Chekiang Province.

Air and ground units will be employed to capture and secure airfields in the vicinity of Lishui, Chuhsien and Yushan. Other airstrips in Chekiang Province will be neutralized by our air units at an opportune time.

Consideration will be given as to whether certain air bases, together with the accompanying military installations and important lines of communication, will be destroyed completely or whether they will be occupied for a certain period of time.

In order to reinforce the 1st Air Brigade during its attacks against the airfields in Chekiang Province, in early April the Southern Army was directed to send the 62d Air Regiment (28 heavy bombers)and the 90th Air Regiment (20 light bombers) to central China.

On 30 April, Imperial General Headquarters ordered the Chekiang-Kiangsi Operation to be undertaken at the earliest possible date. The operation proceeded smoothly with the 1st Air Brigade cooperating with the ground units when required. Not only did the Brigade sup-port the ground forces by bombing the opposing forces but its reconnaissance planes greatly assisted the operation by supplying information in regard to enemy ground movements, positions and strength.

Subsequent to the occupation of the captured areas, by mid-August units of the 13th Army had destroyed the Yushan, Chuhsien and Lishui airfields. The enemy, however, continued to reinforce their air force around Hengyang and Kweilin and, with the withdrawal of the Eleventh and Thirteenth Armies, it was feared that using air-fields in Kiangsi and western Chekiang Provinces as staging areas, they would bomb the Homeland. The 1st Air Brigade, therefore, in spite of the fact that its fighting strength was gradually diminishing, repeatedly attacked and damaged airfields in this area.

China Expedition

While they had been manufacturing Western designs under license in the 1920s, Japanese aircraft builders had been catching up on the fine points of aeronautical design. In the early 1930s, they were ready to proceed with designs of their own.

In February 1934, Imperial Navy air headquarters issued a 9-shi specification calling for a new single-seat fighter. Although carrier-based capability was virtually implicit in a navy requirement, one of its chief architects, Lt. Cmdr. Hideo Sawai, had deliberately avoided specific reference to such characteristics, concerned that it would inhibit the designers. In contrast to British and American naval aviation planners, Sawai wanted the manufacturers to produce a high-performance fighter that would bring Japan up to world standard—the matter of adapting and equipping it for operations from carrier decks would be dealt with afterward. The specification called for a maximum speed of 350 kilometers per hour (217 miles per hour) at 3,000 meters (9,840 feet) and the ability to climb to 5,000 meters (16,405 feet) within 6.5 minutes. Armament was to consist of two 7.7mm machine guns, wingspan would not exceed 11 meters (36 feet), and length no more than 8 meters (26 1/2 feet).

Among those who sought to meet the requirement was Mitsubishi’s chief designer, Jiro Horikoshi. After giving cursory consideration to other configurations, Horikoshi determined that the fighter must be a low-wing monoplane, with attention paid to the cleanest possible aerodynamics and to the minimum possible weight. The airframe he designed used stressed-skin aluminum over a two-spar box-type wing structure of inverted gull form, which was later altered into a flat center section with dihedral for the outer wing panels. After considering the possibility of incorporating retractable landing gear into his design, Horikoshi rejected it on the grounds that the 10 percent decrease in drag would result in only a 3 percent increase in speed, not enough to justify the system’s greater weight and complexity. Instead, his monoplane would have fixed undercarriage, with streamlined fairings over the wheels.

The first Ka-14 prototype, powered by a 550-horsepower Nakajima Kotobuki 5 nine-cylinder radial engine, was completed in January 1935, just eleven months after Mitsubishi received the 9-shi specification. During its first flight tests in February, it reached a speed of 444 kilometers per hour (276 miles per hour) at 10,500 feet, exceeding both the navy’s requirement and Horikoshi’s own expectations. Nevertheless, the Ka-14 had a great obstacle to overcome when it competed with the Nakajima A4N1 biplane in the autumn of 1935, because of the almost insurmountable prejudice in favor of dogfighting capabilities over all others among senior JNAF officers. The Ka-14’s low wing loading made it extremely maneuverable for a monoplane, but it still could not match the maneuverability of the A4N1—until the rules of mock combat were altered to include climb and dive tactics. That change gave the Ka-14 such an overall edge that even Minoru Genda, one of the most ardent biplane partisans, was won over to the new type.

After further development—and an unsuccessful attempt to interest the army in the design—Mitsubishi was able to put its monoplane into production as the A5M1 Model 96 carrier fighter in the autumn of 1936. An improved version with a 610-horsepower Kotobuki 2 KAI 3ko engine, a longer chord cowling, and a three-blade propeller in place of the two-blade airscrew entered production in the late spring of 1937 as the A5M2-ko. The outbreak of war with China on July 7, 1937, lent urgency to the JNAF’s efforts to hasten the A5M to operational units, and the newly formed 13th Kokutai (Air Group) got its first monoplanes just four days later.

“Battle of Shanghai”

Initially, the Japanese army advanced quickly, taking Beijing and Tientsin; but resistance stiffened as it approached Shanghai, and at the same time Japan’s regular arsenal of biplanes was proving unable to achieve a decisive degree of air superiority over the mixed bag of Chinese aircraft that opposed them. The need for such an edge became critical on August 14, when nine Mitsubishi G3M2s of the Kanoya Kokutai, led by Lt. Cmdr. Shinichi Nitta, left Matsuyama (Sung Shan) air base near Taipei, Taiwan, crossed the Formosa Strait and tried to bomb Jienqiao training field near Hangzhou, while another nine G3Ms led by Lt. Cmdr. Nantaro Asano attacked Guangde airfield. Chinese intelligence had learned of the coming mission and Colonel Kao Zihang, commander of the 4th Pursuit Group at Zhoujiakao, had ordered his 21st, 22nd, and 23rd Squadrons to Jienqiao, where their Curtiss Hawks would refuel and take off to intercept the raiders.

Kao’s fighters were the last of a long line of classic biplanes that had begun in 1925 with the P-1 Hawk (the first Curtiss to bear the name), and which culminated in the F11C-2 Goshawk. Final refinements in the Goshawk were metal wings and hand-cranked retractable landing gear on the XF11C-3, inspired by that of the Grumman XFF-1 two-seat fighter. Entering US Navy service in May 1933, the F11C-3—later redesignated as the BF2C-1 fighter-bomber—joined the Grumman F3F and Polikarpov I-153 as the only single-seat biplane fighters with retractable undercarriage to achieve quantity production.

Export versions of both Goshawk variants reverted to wooden wing structures, the fixed-gear plane being called the Hawk II and the retractable model the Hawk III. Powered by a 740-horsepower Wright R-1820-F53 radial engine, the Hawk III had a top speed of 240 miles per hour, mounted two .30-caliber Browning machine guns, and served in the air arms of Thailand and Argentina as well as China, which imported its first twelve in March 1936. Another ninety arrived in crates and were assembled at the Central Manufacturing Company at Hangzhou. The Chinese had seventy-two operational when the Japanese invaded, as well as fifty Hawk IIs.

August 14 began with Chinese air attacks against the Japanese army in Shanghai and against supporting naval units offshore, including Hawks of the 5th Pursuit Group carrying one 250-kilogram bomb each. Lieutenant Liang Hongwen in plane No. 2401 of the 24th Pursuit Squadron was credited with hitting the stern of the Japanese light cruiser Idzumo off Nantong, but it turned out to be a near miss—which was fortunate, since his target was in fact the British heavy cruiser Cumberland. Two other Chinese bombs fell near the American heavy cruiser Augusta. Another “international incident” occurred that afternoon when three Hawks from the 24th attacked the Japanese-occupied Kungda Textile Factory, but one of their bombs fell on the Nanking Road in the International Settlement. Meanwhile, Liang came under attack by an aggressively flown Nakajima E8N1 floatplane from the light cruiser Sendai, and was so badly shot about that he had to force land and died of his injuries soon after. Next, five Hawk IIs and nine Hawk IIIs made another attempt to bomb the Kungda factory, and some also attacked the floatplane, scoring fifteen hits before it lost them in a cloud.

Poor though the Chinese bombing performance was, it spurred Vice Adm. Kiyoshi Hasegawa, commander of the Japanese Third Fleet, to order attacks against their airfields. Due to typhoon weather conditions, however, the only unit game to defy them was the Kanoya Kokutai with its modern G3Ms—all-metal twin-engine monoplanes capable of 232 miles per hour and of mounting three 7.7mm machine guns. They took off at 1305 hours Formosa time, but storm clouds and poor visibility limited their altitude to 1,641 feet. They would also have to carry out their mission without fighter escort, but the Japanese were not overly concerned, arrogantly assuming that they would not need it against the inept Chinese.

The 4th Group’s Hawk IIIs were still in the process of refueling at Jienqiao when Nitto’s bombers arrived, strung out due to the weather, which made it hazardous to fly in formation. Kao, boarding his personal Hawk III marked IV-I, ordered all fighters to scramble up, ready or not. This had grave consequences for two of them—Hawk III 2105 of the 21st Pursuit Squadron ran out of fuel and crashed, mortally injuring Lt. Liu Shufan, and 2106 force landed, injuring Lt. Chin Anyi. The rest laid into the Japanese, and Colonel Kao, after silencing two gunners, closed to twenty meters to shoot a G3M, piloted by Petty Officer 3rd Class Iyoshio Momosaki, down in flames over Banshan. He then attacked Warrant Officer Fujio Yamashita’s bomber, crippling its left engine with fourteen hits, along with twenty-one in its right wing, and thirty-eight to the fuselage before his fuel gave out, compelling him to disengage and force land at Jienqiao. A third G3M, piloted by Petty Officer 1st Class Yanase Mitsui, and which was swarmed by 21st Squadron Hawk IIIs flown by Capt. Lee Guitan, Lt. Wang Wenhua, and Liu Chisheng, went down near Chiaosi.

At 1800 hours Asano’s nine G3Ms arrived over Guangde in V formation but only scored one bomb hit. As they made for home, they encountered Capt. Chow Tingfong, commander of the 34th Provisional Pursuit Squadron, who had been test-flying a Hawk III. Although he had no ammunition, Chow attacked and managed to break up the formation. As the Japanese flew on, they ran into the 22nd Pursuit Squadron, and one of its pilots, Lt. Cheng Hsiaoyu, hit the right engine and wing tank of Warrant Officer Hitoshi Ogawa’s G3M. Ogawa pressed on for Taiwan but ran out of fuel short of his goal and ditched near the Keelung harbor lighthouse, where he and his crew were rescued. Yamashita managed to get his riddled bomber back to Matsuyama on one engine, but its landing gear collapsed on landing, and it was written off.

Though overlooked in the West, the “Battle of Shanghai” had multiple significances in aviation annals. In 1940 the Republic of China pronounced August 14 as “Air Force Day.” Indeed, Colonel Kao had scored his air arm’s first aerial victories. To his shared kill that day, Liu Chisheng would add ten more flying Hawks, I-16s, and I-152s, to become China’s ace of aces and a major general in the Republic of China Air Force. In terms of air strategy, the Chinese fighters’ success struck a serious blow to Italian general Giulio Douhet’s widely accepted theory that bombers alone could win wars. Conversely, the Japanese were rudely awakened to the folly of sending their bombers in unescorted, and to the critical need for a fighter capable of seizing control of the sky.

Land-based Japanese navy units, augmented by the air groups of the light carrier Hosho off Shanghai, were joined on August 15 by the large carrier Kaga, and both vessels achieved a marginal degree of local air superiority with their aging Nakajima A2N1 fighters.

First Nakajima Ki.27-Otsu Type 97 fighter combat

Curiously, the Japanese Army Air Force (JAAF) was slower than the navy in adopting more innovative and potent fighter designs. One reason was its longer adherence to the Japanese penchant for comparing aerial combat to the swordsman’s art of kendo, stressing dexterity of maneuver. Finally, in June 1935, the Koku Hombu (Army Headquarters) issued a requirement for an “advanced fighter” to replace the Kawasaki Ki.10 biplane. The new fighter was to be capable of 280 miles per hour in level flight and of reaching 16,405 feet (5,000 meters) in less than six minutes, but would still mount two 7.7mm Type 89 machine guns.

Nakajima’s design team, led by Tei Koyama and assisted by Minoru Ota and Hideo Itokawa, had already had some experience with externally braced monoplane designs when they learned of the new army requirement. They went on to design a small cantilever monoplane around the Nakajima Kotobuki II-Kai nine-cylinder radial—a license-built version of the Bristol Jupiter—using all-metal stressed-skin construction. As with the A5M, fixed landing gear enclosed within two streamlined fairings was selected over the heavier and more complex retractable undercarriage, but an enclosed canopy was incorporated into the second prototype. Increased wing area and the incorporation of wing flaps kept the fighter maneuverable enough to satisfy the Koku Hombu, which chose it over its faster competitor, the Kawasaki Ki.28, following trials in the spring of 1937. Powered by an improved 710-horsepower Nakajima Ha-I-Otsu engine driving a two-bladed all-metal two-pitch (ground-adjustable) Sumitomo PE propeller, the production version of the Nakajima Ki.27-Otsu Type 97 fighter had a maximum speed of 291 miles per hour at 13,125 feet.

So confident was Nakajima in its new fighter that it was making production preparations at its new plant at Ota even before the army’s order became official on December 27, 1937. Even the most conservative pilots were delighted with the new fighter’s maneuverability, as well as with its higher performance.

Eager to blood the new fighter in combat, the army dispatched three of the first planes to leave the assembly line to the 1st Chutai of the 2nd Hiko Daitai (Air Battalion), which was then flying Ki.10s from Yangzhou, northern China. Just one week after their arrival, on April 10, 1938, Capt. Tateo Kato, commander of the 1st Chutai, was leading the trio along with twelve Ki.10s on patrol near Ma Muchi when they encountered eighteen Polikarpov I-152s (also called I-15bis, which were upgraded I-15s with cabane struts in place of the gulled upper wings) returning from an attack on Japanese headquarters at Chao Chuang. The Japanese promptly attacked the lower formation of eleven I-152s of the 4th Pursuit Group at 4,500 meters altitude, and in the dogfight that followed, Kato’s Ki.27s zeroed in on Lt. Chang Guangming, who tried to escape with a climbing half-roll before he was hit. Bailing out just before his plane caught fire, Chang survived a Japanese attempt to strafe him in his parachute before alighting with an injured back.

At that point the seven I-152s of the 3rd Pursuit Group’s 8th Squadron, which were five hundred meters above the 4th Group’s flight, dived on the Japanese. The 8th’s deputy commander, Capt. Zhu Jiaxun, shot Sgt. Maj. Risaburo Saito off the tail of a 23rd Pursuit Squadron I-152, only to see the Ki.27 veer away to collide with Lt. Chen Huimin’s Polikarpov. Chen managed to bail out before both planes crashed, surviving with a leg injury. Meanwhile, the two remaining Ki.27s shot the cowling off Zhu’s plane, but he managed to evade them and force landed in a wheat field. Zhu’s and a second force-landed plane were subsequently recovered for repair. He was credited with Saito as the second of three victories he would score in I-152s; he would later add two more in Gloster Gladiators.

By the time the two sides finally disengaged, the Japanese had claimed twenty-four Chinese planes—more than they had been fighting—including two for Kato, two for Warrant Officer Morita, and a posthumous credit for Saito. Among the Ki.10 pilots, Sgt. Tokuya Sudo was credited with two and 1st Lt. Iori Sakai with three, but Lt. Yonesuke Fukuyama returned to base with wounds from which he died in hospital shortly after. Two Ki.10s force landed short of Yangzhou, and two others crash-landed on the airfield. Actual Chinese losses were two 4th Pursuit Group planes shot down, with Sun Jinjen killed, and three others, flown by Lin Yuexing, Wang Denbi, and Li Tingcai, force landing due to fuel exhaustion, but which were later recovered; a 3rd Pursuit Group plane lost with its pilot, Liang Zihang; and two 3rd Pursuit planes returning with their pilots, Liu Tianlung and Huang Yin, wounded.

Over the next few weeks, the 2nd Daitai supported the army’s Hsuchow campaign, intended to give the Japanese complete control of the Peking-Nanking railway. Chinese aerial opposition became infrequent, but on May 20, three Ki.27s of the Daitai’s headquarters flight took on ten Chinese, resulting in three credited to Capt. Mitsugu Sawada, one to Lt. Katsumi Anma, and one to Sgt. H. Wada, as well as seven more by the Ki.10s. In actuality, four I-152s of the 17th Pursuit Squadron were shot down, Zhu Qunqui and Qiu Guo bailing out of their flaming planes. In addition, Zhang Sheungren and William Tang force landed their shot-up fighters, and that of their commander, Sen Jiuliu, returned damaged, while two of the 22nd Pursuit Group’s Hawk IIIs, 2201 flown by Feng Yuhe and Chao Mosheng’s 2205, never returned.

The 2nd Hiko Daitai was still in the process of replacing its Ki.10s with Ki.27s in August 1938 when a restructuring of the JAAF resulted in its being redesignated the 64th Koku Sentai (Air Regiment). Adoption of the Ki.27 proceeded rapidly thereafter, and the fighter went on to its most celebrated period during the undeclared conflict between Japan and the Soviet Union in the Nomonhan region of Mongolia and Manchuria in the summer of 1939.