Beginning in April 1943 the 6th FD began to move Army air units permanently from Rabaul to Wewak. Prior to this Wewak had been used by both Japanese army and navy aircraft as a temporary operating base. Now it was to be built into the army’s major airfield complex in New Guinea. Aircraft transiting from Rabaul to Wewak sometimes made stop overs or force landings at Tuluvu.

On April 30th six bombers bound for Wewak landed at Tuluvu probably due to the bad weather prevalent that day. They were soon discovered by a B-24 and attacked. One bomber was holed several times by machine gun hits. Japanese records available to the author are incomplete and do not identify the type of aircraft.

An Allied intelligence summary reported this incident in the following terms: “It has been reported that a new landing ground is being developed at Cape Gloucester, comprising two runways. The visual sightings of 6 type 97 M/B SALLYS on the old strip, on April 30, is the first evidence of substantial operational use of this aerodrome.” The 14th FR flying Type 97 heavy bombers (officially designated heavy bombers by the Japanese, they were medium bombers by U.S. standards) remained headquartered at Rabaul at this time but six SALLYS were subsequently identified in aerial photographs taken of Wewak.

The Japanese worked mostly at night. Among their first tasks, however, was to burn off many acres of grassland. This could hardly be concealed for long. What the Japanese called the West Airfield would become No.1 strip or the old airfield in Allied reports. The new (East) airfield would become No. 2 strip to the Allies. The Americans followed the development of Cape Gloucester closely.

On May 3rd a B-24 flying about 20 miles northwest of Cape Gloucester encountered a reported dozen ZEROS. Two of these attacked and one was claimed as possibly damaged. Later a fighter was seen on the runway at Tuluvu where a twin-engine aircraft had also been reported. That same day a reconnaissance from 7,000 feet reported no aircraft were visible. In subsequent reconnaissance of Tuluvu two aircraft were reported present on several occasions though in some reports it was suggested they were dummy aircraft. (Information of such seemingly limited certainty and pertinence is mentioned here only as it may become relevant in trying to identify aircraft later found at Tuluvu.)

The other Japanese airfield on New Britain outside the Rabaul complex that had been in regular use as an advanced landing ground was Surumi (Gasmata) on the south coast. Allied aircraft hammered this airfield repeatedly during May. Seventeen attacks were carried out in one six-day period. Surumi was out of action much of the time and was abandoned as an operational airfield. In its place the Navy developed a new airfield at Gavuvu on Cape Hoskins roughly due north of Surumi on New Britain’s north coast. Though not as heavily hit as Surumi, Tuluvu nonetheless suffered some thirty attacks during May.

The intensive attacks on Surumi and Tuluvu did not go unanswered. Japanese army and navy fighters intercepted Allied bombers over western New Guinea several times in the second half of May. Most of the interceptions were near Surumi. On May 23rd the navy sent a total of twenty-four Zeros in relays to patrol western New Britain between Tuluvu and Surumi. Four of these fighters encountered five B-24s and claimed two damaged. The B-24s claimed two of a reported ten fighters destroyed (interestingly the fighters were reported as a mix of Zeros and FW-190’s).

The number of attacks mentioned above for Surumi is from an Allied intelligence summary. Attack figures for Tuluvu, unless otherwise stated, are from Japanese sources usually from the 4th Air Intelligence Unit detachment. No attempt has been made to reconcile these figures with Allied reports. Japanese figures are not always consistent. After the arrival the 39th Anti-aircraft Battalion in June 1943, its reports of air attacks vary somewhat from those of the intelligence unit (the AA unit was concentrated at Tuluvu, the Intel unit had detachments further dispersed).

On May 15th two of the recently arrived Type 3 fighters (Ki 61) appeared over Tuluvu. This was probably a familiarization flight in advance of the first offensive mission of this type in the area. Two days later Type 3 fighters of the 68th FR escorted Type 97 heavy bombers of the 14th FR from Rabaul to attack Wau. Along with Lae and Surumi the airfield at Tuluvu could provide haven to aircraft damaged or short of fuel returning to Rabaul from raids on New Guinea. One of the Hiens (Swallow, a name later applied to the Type 3 fighter) returning from Wau encountered difficulties and crashed near Tuluvu killing the pilot Sgt. Maj. Ginzo Shirayama.

The intensity of Allied air attacks on Tuluvu declined appreciably in late May and into June. For the entire month of June the Japanese recorded 92 over-flights but only 10 bombing or strafing attacks. That did not mean complete relief however. In the early morning hours of June 8th a single Catalina flying boat dropped bombs that totally destroyed a barracks. The relative respite did facilitate progress on the new runway.

Work got underway on the East airfield on April 28th. For a month or so the available labor force was divided between West and East airfields. Major Mukai planned for all available labor to work on the new airfield after May 25th. His plan called for completion of the first phase of construction – a 1400x100 meters runway and dispersal area – by July 31st. From August to October work would concentrate on revetments followed by additional work in November on supply and ammunition dumps and connecting roads. Work was to be carried out at night supplemented by daytime work depending on circumstances.

A Japanese army-navy agreement covering operations in the Southeast Area executed at the end of March 1943 assigned the army general responsibility for air operations in New Guinea with the navy responsible for the Solomons. This agreement plus the build up of army air strength in May and June led to an increased operations tempo in New Guinea. Pursuant to the army-navy agreement Tuluvu was to be a joint use airfield under army jurisdiction.

Tuluvu airfield was hardly in a position to play a major role in air operations. It could refuel aircraft and make minor repairs but it had no stocks of ammunition. Personnel were also in short supply. The 21st Ab Tuluvu Expeditionary Force consisted of one officer (CO 2d Lt Takeo Sakai) and 33 men. Detachments of the 5th Air Signals Regiment and 2nd Meteorological Regiment numbered barely twenty men. The air intelligence detachment was larger but its force of about fifty troops was scattered at a number of locations away from the headquarters at Tuluvu. To these army air units were soon added several personnel from some air units of the navy’s 11th Air Fleet.

The summary of operations and strength of the 6th FD in May 1943 are shown in figures 1 and 2. Comparative strength for the 5th Air Force is shown in figure 3.

FIGURE 1: 6th FD OPERATIONS – MAY 1943

Targets: airfields at Hagen, Wilhelm, Kianantu, Wau, Buna, and Bulldog; army co-operation, Salamaua front; enemy ships north of Buna. Losses and results are aircraft.

Offensive Operations

Defensive Operations

Note - The above figures are for combat missions and do not include training or administrative flights. For example, regiments subordinate to the 12th FB (1st, 11th, 24th and 68th FRs) flew a total of 1,255 sorties (about 200 more than shown in the figure). In addition aircraft attached to the Brigade HQ flew another 105 sorties using Type 100 command recon aircraft, Type 2 two-seat fighters, Type 99 light bombers and Type 1 fighters.

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FIGURE 2: 6TH FD STRENGTH – 31 MAY 1943

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FIGURE 3: 5th AIR FORCE – U.S. AIRCRAFT 31 MAY ‘43

Category and types In Commission/Assigned

Note – Not shown, 7 squadrons of No. 9 Operational Group (RAAF) assigned to the 5th Air Force. Aircraft delivered to 5th AF during May, most not assigned to units by 31 May, include: 94 B-25s, 31 B-24s and 15 P-39Ns.

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The figures above (at least the operational numbers) imply that a rough numerical parity existed between the opposing air forces. It was a parity that was not to last. In June the number of P-38s in the 5th Air Force would jump from 83 to 156 and a new P-38 group (475th FG) would be activated. During the same month 59 P-47Ds (348th FG) arrived in Australia and the following month an additional 56 P-47s and 36 P-38s arrived. Late production P-39s and P-40s were also arriving to replace worn-out older versions of the same models. Additional fighter and bomber groups would soon strengthen the 5th Air Force. The Japanese could not hope to match this build-up. As new aircraft arrived and older ones were retired the serviceability rate of 5th Air Force planes rose. The serviceability rate of Japanese aircraft dropped dramatically under tropical conditions (conditions that were worse at Wewak than at Rabaul).

In June 1943 the situation in the Southeast Area actually appeared somewhat hopeful to the Japanese. They intended to strengthen their position in the central Solomons and forestall any Allied offensive there. In New Guinea they had more ambitious plans. They not only intended to hold the ground they occupied but offensive operations were planned to gain Wau, Bena Bena and counter Allied encroachments in the Mt. Hagen area. Air power was to be strengthened by shifting army air units from the Netherlands East Indies to New Guinea.

Here a brief commentary on differing perspectives might be appropriate. General Kenney, the Allied air commander, in a post-war book suggested that the Allied development of airfields on the high plateau west of Lae was a ruse to deceive the Japanese about his true intentions and actions in developing an airfield at Tsili Tsili. John Warden used this incident as in illustration in his seminal work, The Air Campaign (National Defense University Press, 1988), and referred to these as “fake” airfields. To several hundred Australian troops operating in the region around Bena Bena, these airfields were anything but fake. Transports landing on these fields were their sole source of logistic support. When early Japanese raids holed these airfields sufficiently to render them unserviceable, the Australians employed over 3,000 native (Chimbu) laborers to repair them with hand tools and employed hundreds of less reliable natives to raise and gather food for the workers. The Australians were not intent on “raising dust” to gather Japanese attention as General Kenney suggests but on securing their line of communications. This may be a minor point. The Japanese constantly monitored these airfields and while doing so they missed the development at Tsili Tsili.

The Japanese considered the airfields a potential threat to their own airfields on New Guinea’s north coast but more immediately considered the Australian ground forces gathered on high ground flanking their position at Lae to be a serious concern. The Japanese were trying to develop an overland supply route to Lae and the Australian forces might interfere with its completion. They might even pose a direct threat to Lae. The Japanese were worried about enemy capabilities since they could not divine enemy intent. The Allies eventually did strike the Japanese on Lae’s western flank but with a drop of American parachute troops not with Australian forces from the Bena Bena region.

In New Guinea natives labored on the airfields near Bena Bena and American aviation engineers developed Tsili Tsili. Progress continued at Tuluvu as well. In June 1943 several hundred troops per day were working on the East airfield. These included troops from local aviation units but most of the labor came from transient troops or those permanently assigned to the 65th Brigade now the senior command in western New Britain. From Busching to Natamo, western New Britain’s permanent garrison numbered some 3,000 troops.

With completion of the new airfield scheduled for the end of July additional aviation support units arrived at Tuluvu. These included a detachment of the 209th Ab, a light bomber support unit, as well as most of the 26th Airfield Company (Ac) commanded by 1Lt. Shigeo Oyama. Tuluvu acquired the expertise to service fighters, bombers and other types of aircraft of both services.

On June 12th a Type 1 model 1 fighter returning to Rabaul landed at Tuluvu to refuel. This fighter had probably been involved in combat over Bena Bena earlier. That combat involved nine P-38’s of the 9th FS and ten OSCARS of which the Americans claimed two destroyed. One of the victorious pilots was 1Lt. Richard I. “Dick” Bong later to become America’s all-time leading ace. Bong returned to base with his P-38 peppered with 7.7 mm hits. The fighter landing at Tuluvu was from the 11th FR. This regiment was transferred to Japan soon after this action.

Two days later another Type 1 fighter or Hayabusa (Falcon) landed at Tuluvu. This aircraft was from the 12th Flying Brigade (FB) parent unit of the 11th FR and landed for fuel while en route to Bena Bena. The Japanese were attempting to disrupt American air transport flights to Bena Bena. No combat occurred on this particular day, however.

On June 15th the 6th FD sent three Type 99 light bombers transporting several thousand rounds of 7.7mm and 12.7mm aircraft ammunition to Tuluvu. The bombers were escorted by two Type 2 heavy fighters (Ki 45) of the 13th FR. This was the first recorded appearance of the latter type aircraft at Tuluvu. Japanese records are unclear as to whether one of these aircraft was damaged in landing or another aircraft that landed the following day was damaged. Subsequently another flight by a Type 99 bomber brought spare parts to repair the damaged fighter. Four additional flights by light bombers followed from the 17th to the 22nd June. One of these took Lt. Gen. Goro Mano, commander of the 65th Brigade, to his new assignment as commander of
the 41st Division. Also on June 22nd a Type 1 fighter of the 1st FR made an emergency landing after flying convoy cover at Hansa Bay. Six days later another Type 99 bomber arrived transporting a ground force commander.

On June 30th, 1943, the Allies began ground offensives at several locations in the Southeast Area. These operations involved both the SWPA and South Pacific (SoPac) command. In the Solomons Rendova Island and other parts of the New Georgia Group were invaded. In New Guinea landings took place at Nassau Bay south of Salamaua and the offshore islands of Kiriwina and Woodlark were occupied.

At Tuluvu the first ten days of July saw several arrivals of Type 99 light bombers mainly for liaison or transport purposes. One hundred-thirty 100kg bombs arrived by boat on July 6th. Additional ammunition deliveries allowed Tuluvu to service navy Zero fighters and army Type 2 heavy fighters in addition to Type 1 and Type 3 fighters.

A number of 1st FR Type 1 fighters arrived during early July. One landed with mechanical trouble on the 1st and two more landed on the 8th.

The 11th of July was a busy and unusual day. One bomber from the 83rd FCs landed due to bad weather and no less than ten Type 3 fighters of the 78th FR landed after combat operations.

The 78th FR escorted bombers to Nassau Bay that day. There were combats over New Guinea on the 11th. The P-39s of the 36th FS and the P-38s of the 9th and 80th FS were engaged in the Wau-Mubo area north of Nassau Bay. They made claims for several aircraft identified as OSCARS, a ZERO and a ZEKE but reported no bombers. Their victims were from the 24th FR not the 78th. Japanese accounts relate that two Type 3 fighters were lost with their pilots near Cape Cretin (on the New Guinea coast southwest of Tuluvu) but attribute the losses to accident. This seems to have been a difficult day for the Hien pilots of 78th FR but not due to American fighters.

On the following day a Type 97 heavy bomber was sent by the 14th FB (parent unit of the 68th and 78th FRs). This aircraft transported personnel. There is little doubt they were maintenance personnel to aid in servicing the Type 3 fighters. The mechanical unreliability of the Type 3 fighter in its early operations has often been reported and this incident and the earlier crash at Tuluvu seem to confirm it. The 68th arrived at Truk in April 1943 with fifty-four fighters. Two weeks later forty-two of these fighters were ready to transfer to Rabaul. At least nine fighters attempting to fly down to Rabaul were lost due to mechanical problems and navigational errors and others turned back. An attempted mass transfer flight by light bombers of 208th FR and fighters of 68th FR on May 3rd also went awry. The whole flight was turned back by weather but the 68th lost two fighters in a head-on runway collision and a third was missing. After two weeks of trying part of the regiment was still at Truk and only sixteen fighters were serviceable at Rabaul. As noted in Figure 2 the regiment had only 26 aircraft on strength at the end of May. Thus after several weeks in the area it had lost or not yet assembled half its strength in the combat zone. Likewise the 78th FR lost a dozen of its forty-five fighters while transferring to Rabaul via the air route through the Philippines in June. The incident on this day shows that the 78th continued to suffer non-combat losses in its early operations.

On the 13th another Type 3 fighter landed for fuel while en route from Rabaul to Wewak. Also on the 13th a Type 99 army reconnaissance plane of the 83rd FCs brought Maj. Gen. Eizo Yamada, commander of the 1st Shipping Group, from Kavieng to Tuluvu. In August General Yamada took command of Japanese combat elements defending the strategic Finschhafen area on New Guinea’s north coast.

July the 17th found three Type 3 fighters of the 68th FR landing at Tuluvu with mechanical troubles while en route from Rabaul to Wewak. By the 20th all these aircraft had resumed their journey.

On the 18th a Type 1 model 2 fighter (Ki 43-II) of the 24th FR arrived at Tuluvu for liaison purposes. The 24th was based at But and like other fighters in the But-Wewak area might have occasion to use Tuluvu as an emergency landing field during its operations. The airfield was also being considered as an advanced operating base. A Type 100 command reconnaissance plane of the 81st FCs diverted into Tuluvu by bad weather joined the Hayabusa on the field.

On the 19th two Type 3 fighters from the 78th FR joined the remaining Hien of the 68th still on the field. Their jettison tanks had failed to suction properly during their advance to Wewak. The arrival of a Type 99 light bomber, used as a transport by the 6th FD, the following day may be related to the trouble with these fighters.

The Type 3 fighters of the 68th and 78th FR were now based at Wewak. Starting on July 18th these units began a series of operations over the Salamaua region during which they claimed their first air victories and suffered their first combat losses.

On July 23rd two Type 3 fighters of the 78th FR landed at Tuluvu for fuel after combat. These were part of a formation of forty-nine fighters and bombers that carried out attacks near Salamaua. This formation ran into three squadrons of P-38 Lightnings. The 39th FS claimed one “type 3 fighter” among its victims near Salamaua. Later near Madang the 80th FS engaged the formation and claimed one “in-line engine fighter”. Others were claimed as probably destroyed along with claims for ZEKES and OSCARS. Two type 3 fighters, one from each regiment, were lost.

These early combats revealed only a little about the new fighter to the Americans. Several American pilots did report that in a shallow dive at various altitudes from 18,000 feet to low level the TONY (Allied codename) stayed with or could not be overtaken by the P-38 at 400 M.P.H. indicated airspeed. This speed (over 540 m.p.h. TAS at 18,000 feet) was considerably faster than anything reported for a ZEKE or OSCAR. Pilots also said no TONYS were seen to explode in mid-air and concentrated close range fire was required in order to flame them.

In July 1943 the Japanese army air effort totaled 1,308 combat sorties slightly less than during May. Fewer defensive missions were flown than during May (578 sorties down from 845) but nearly 200 more offensive sorties were flown in July than in May. Much of this effort was either expended in ground support missions (190 sorties) or against forward airfields that so concerned the Japanese but played a relatively minor role in Allied plans. For the month of July the Japanese recorded more than 2,000 Allied sorties over their principal bases in New Guinea. Most of the attack missions targeted the Lae area while only a handful of reconnaissance flights were noted over Wewak. The Japanese considered Wewak, now home of a heavy concentration of airpower, to be relatively safe.

The 65th Brigade and other units in western New Britain received supplies and reinforcements through a stream of MLCs and other small craft that traveled along barge routes that had become well established. They generally traveled at night and rested in barge hideouts during the day. MLCs also crossed the straights and brought supplies to New Guinea. Convoys of large transports put in at Wewak but only submarines and small vessels supplied Lae. Tuluvu remained a terminus for destroyer re-supply missions in addition to barge traffic. A series of such missions was planned for the end of July and early August.

The 11th FR had returned to Japan in June and the 1st FR was scheduled to follow in early August. Most of the Japanese army’s fighter strength had shifted from Rabaul to Wewak where it was engaged in brisk combat operations supporting the 18th Army’s ground campaign and challenging Allied airpower. Under the circumstances the army requested the navy to share the burden of providing air cover for the coming destroyer transport missions. Despite its heavy commitments in the Solomons, the navy agreed.

When the Southeast Area Fleet agreed to supply air cover to the Tuluvu re-supply mission in late July 1943 it did so with a fighter force that had undergone significant changes in the preceding month. Early in May 251 Ku (“Ku” for “Air” short for Kokutai or Air Unit more accurately Air Group), the former Tainan Ku, returned to Rabaul from six months reorganization in Japan. For the next two months Air Groups 204, 251 and 582 made up the Japanese navy’s fighter force in the area. On the morning of June 30th these three groups had in total eighty-three operational Zero fighters. These were mainly Zero model 21s and Zero model 22s with a small number of model 32s. Opposing them in the Solomons were 213 operational Allied fighters. June 30th was a day of heavy combat and the Japanese lost thirteen fighters in combat or operationally reducing the available fighter force to some seventy operational aircraft.

To meet the new threat in the central Solomons the navy sent in reinforcements. The principal movements included the Ryuho fighter squadron (25 Zero 21s) arriving at Rabaul 2-4 July and transferred to Buin soon thereafter; twenty carrier pilots transferred to Air Groups 204, 251 and 582 on July 3d; a chutai (8 fighters) of 253 Ku to Buin on July 4th; 201 Ku advanced detachment of eighteen fighters arriving July 12th with the remainder (45 fighters) a week or so later; and, the Junyo fighter squadron of 19 Zero 21s arriving at Rabaul July 15th and Buin two days later. In the middle of July the fighter squadron of 582 Ku was broken up and its pilots and planes transferred to other groups.

The largest of the newly arrived units was Air Group 201. As of July 1st the group numbered sixty fighters (42 Zero 21s and 18 Zero 22s) and sixty-five pilots. Eight of its pilots had experience ratings of A and were fully capable of any mission, twenty-five others were rated B (nominally 400-1000 hours flying time) and were also capable pilots, but nearly half were rated C denoting they had less than 400 hours total flying time. This suggests many had little more than pilot training and a short tour of operational training. Some probably had three hundred hours or less flying time with little time in a Zero behind them. Such pilots were not generally regarded as fully capable but by force of circumstances were often thrust into combat missions.

The three veteran groups had suffered from a shortage of pilots but the influx of twenty carrier pilots had greatly alleviated the numbers problem but not necessarily helped with experience. The senior of the local Zero units, Air Group 204, had 53 fighters on hand at the middle of the month but only 29 were operational. These included 13 Zero 21s, 4 Zero 32s, and 12 of the latest Zero 22s. To fly these aircraft it had fifty pilots about half of whom were A or B rated but it also numbered a few in a new category, those that had not even completed a full course of operational training (“D” class).

All the Japanese navy air units were subordinate to higher headquarters that were made up of mixed aircraft types. For operational purposes they were grouped differently. The 25th Air Flotilla (known operationally as the 5th Air Attack Force) at Rabaul controlled all medium bombers as the bomber command. The 26th Air Flotilla at Buin was the fighter command. Finally, the headquarters of the 2nd Carrier Division also at Buin controlled carrier bombers and carrier attack planes as a kind of strike command (in U.S. parlance). This organization was extremely flexible and when large numbers of fighters were based at Rabaul and needed to be centrally controlled the 5th Air Attack Force took over that responsibility.