The Story of Nakajima Ki43i No. 750 (Oscar)

"Nakajima Hayabusa Ki-43i, serial number 750 (code named Oscar by the Allied forces) was the rarest member of the Alpine Fighter Collection. It is the last remaining Ki-43 Type I known in the world and indeed until recently it was believed by the Japanese that physical evidence of this very early Type 1 Hayabusa had been left behind in 1945 with only documents and memories left to record the strong role it played during the turbulent war years.

Because of the Oscar’s extreme rarity Tim Wallis decided that the aircraft was to be restored to a taxi condition and to be kept as original as possible. Although operationally it would be quite possible to render the aircraft flyable it is likely that the Hayabusa will never leave the ground again. The value of the aircraft far outweighs the gamble - to lose the Oscar through misadventure would be to lose an entirely unique part of Japanese and World War II history. 
 
In mid-December 1994 restoration on the Oscar began in Alpine’s Wanaka workshop. Ten months later, after two successful taxiing exercises, the fully restored plane found its place next door in the Fighter Pilots Museum. The months of intensive work had produced many dramatic moments, both high and low, for the couple in charge of restoration, Jan Bullock and Doug James; they agree however that, along with the successful first engine run, the highlight was the visit in September by a group of veteran Japanese Army Airforce pilots. 
 
The Oscar was a plane which held a special place in the hearts of veterans who flew the aircraft. Mention the Hayabusa to some Japanese elders and you may be told there is a song about it - the only Japanese aircraft to have had a song written for it and one which is still sung in Japan today. Each member of the visiting group, who had made a special trip from Japan to view the aircraft on completion of restoration, became very emotional as they laid their hands on the Oscar. Then they gathered together in front of it and sang the Song of the Hayabusa: 
 
With revolving sound of the engine  
Hayabusa goes beyond the clouds. 
Rising Sun is shining on the wing, 
Red Eagle stays on the side, 
That is the sign of our fighter. 
 
Passed through many fights, 
In the rain of bullets, 
Only believing in our victory, 
Sharing destiny with my plane, 
We fly them by our spirits. 
 
Being in years of battle, 
We are honoured so many times, 
All achieved with tears, 
Oh, they have all gone with a smile, 
And now live in our hearts. 
 
Jan Bullock’s part in the restoration had included master minding much of the research into the Oscar’s history. Both she and Doug say now that that moment added immeasurably to their sense of identification with the plane they had restored together.  
 
Watching the group of Japanese veterans sharing memories of the battlefield and of lost friends, while expressing their pride in a strong reliable aircraft, brought home to her the realisation that when war is over hostilities should end. The fighting men of one side feel the same pride, the same sadness, as their wartime adversaries.  
 
Jan and Doug and Oscar occupied the back room here at Alpine for the best part of a year. Their hands-on restoration work was carried out side by side with comprehensive research into the Oscar’s history. This is their story of the Hayabusa Ki-43, manufacturer’s no. 750, Allied code name "Oscar". 
 
Without dwelling on the events in the Pacific during World War 11, the evolvement of the Hayabusa aircraft and the part it played in the Pacific theatre needs to be mentioned briefly to show the role cast both for the aircraft and for the Japanese Army Airforce during these terrible years. Design work began on the Ki-43 in late 1937 with the Army instructing Nakajima to supersede the Type 97 Fighter Ki-27. The specifications were precise and within one year the first prototype was complete. Two further aircraft were completed and test flown in 1939 and were ready for service trials.  
 
To meet the performance requirements further changes were still required to reduce the overall weight and improve manoeuvrability. The unique combat flaps were designed and handling of the aircraft was well reported on. To reduce the weight the retractable undercarriage was made from ground aluminium and the frame material changed to Alclad 24, a lighter alloy. Very little paint was applied to keep weight at a minimum and later on this was to see a large variety of colour scheme as most Ki-43’s were sent to combat in bare aluminium, the individual units producing their own schemes of camouflage. 
 
Basic factory paint included internal corrosion protection, Hinomaru on the wings - after 1942 it became standard also on the fuselage - and the antiglare forward of the canopy. Most propellers were left bare or in dark brown prime. Individual units often colour coded the spinner and propeller to their unit colours. 
 
In Spring 1940 the two bladed wooden propeller was replaced with a metal two bladed propeller, similar to a Hamilton Standard. Production commenced in 1941 at Nakajima’s Ota plant and the Ki-43i reached fighter units some six months later. 
 
The armament consisted of 2 x 7.7mm Type 80 machine guns initially, later to be improved to 1 x 7.7mm and 1 x 12.7mm, each with 250 rounds. The Type 2 Ki-43 saw the armament with 2 x 12.7mm and the Type 3 with 2 x 20mm HO-5 cannons replacing the 12.7mm. Racks for two bombs of 250kg each were found on the wings, however this fighter’s main disadvantage throughout combat was to be the inadequate armament. Because of its light structure, the aircraft often disintegrated when hit, and the Type 2 Ki-43 appeared with some armour plating for the pilot and slightly reduced wing span and other improvements. 
 
The 14 cylinder double row radial engine, with a round shaped oil cooler, was one of the superior engines created by Nakajima, namely Ha-25 Type 99 rated at 980h.p. and the later improved Ha-115 power plant with a two speed super charger and driving a three bladed propeller. The later Ha-115 air intake was moved from under the cowling to its upper lip. 
 
The maximum speed of the Ki-43i was 495km/h at 4,000m, a cruising speed of 320km/h at 2,500m with a maximum range of 745 miles. The later types were improved versions of this initial variant along with other changes, but Ki-43i serial number 750 was one of the earlier Type I aircraft. 
 
The Hayabusa proved itself in action and as a dogfighter its reputation was esteemed. It became popular with the Army Pilots and burst upon the British, Dutch, Americans and Chinese in the Spring of 1942. Second only in numbers to the Navy Zero, a total of 5,919 Ki-43s were manufactured between 1938 and 1945. 
 
In July 1942 the 1st Army Sentai converted from the Type 97 to the Hayabusa fighter and during December 1942 the unit was sent to Rabaul from where, having arrived in January 1943, it participated in attacks on Guadalcanal. In April 1943 the unit’s entire strength went to New Guinea, leaving a small detachment to defend Rabaul. 
 
The 11th Sentai, at the commencement of the Pacific War, also flew the Type 97 fighter aircraft. In August 1942 the unit received the Hayabusa Type 1 aircraft before departing for Singapore in mid September. At the beginning of December, the unit went to Surabaya and on to Truk Island. They now had 61 aircraft and 61 pilots. Mid December they accompanied Navy bombers and landed at Rabaul’s West Airfield to provide air defense for the Rabaul area, participating also in battles over Guadalcanal. In July 1943 the unit was transferred to Manchuria, stopping in Japan to rearm. The Type 1 Hayabusas remained in Rabaul. 
 
In early 1944, 160 fighters were sent from Rabaul leaving practically no air defence. After the evacuation of the major part of the Japanese Air Force from Rabaul, their flying was restricted to local flights in early morning and evenings, before and after Allied fighter patrols were on station. The flights appeared to be for the purpose of morale building. The remaining Japanese aircraft were known as the ’Ghost Squadron", seldom being seen during attacks on Rabaul, and operating in the evenings following the departure of Allied aircraft for their home bases, some distance away, before nightfall.  
 
Our Oscar, Nakajima Ki-43, serial number 750, was constructed in November 1942 and despatched to Truk Island, possibly via an aircraft carrier sent to equip both the 1st and 11th Sentai before their arrival in Rabaul. Oscar 750 saw extensive combat during the next two years and sometime in 1945 had a bad landing which required an engine and propeller change.  
 
One month after the ceasefire, in September 1945, Squadron Leader Denys Hamilton and personnel "discovered" the aircraft four miles from Vunakanau Airfield, extracts from his diary read: 
"We searched for aircraft in good condition, but only found some almost hidden now by the growth and all have been stripped of usable parts. Oscar had been assembled some 3 or 4 miles from the strip and will have to be dismantled and re-assembled at the strip (Vunakanau), the whole operation taking about a week to complete. 
 
The location of the Army Repair unit is very carefully concealed in jungle and would be most difficult to detect from the air There are only foot tracks leading to each aircraft and no roads to give their positions away Besides this, each aircraft is covered with camouflage netting. 
 
I managed to find the Oscar hidden some distance from the strip again and found three men working on it. Vahry was able to get a photograph of it with the men." 
 
The Oscar was duly taken to the Vunakanau airfield in preparation for the fly out to Jacquinot Bay. Again Denys Hamilton records that the Japanese said at the time that the aircraft would not fly. 
"The Oscar has now been almost completely reassembled at the strip and looks as if it should be ready to fly in a couple of days. In the afternoon, I took Fraser to Vunakanau to see the Oscar. The Japanese had sent a message that it is not actually serviceable and we interviewed an engineer warrant officer out there. It is difficult to tell whether they actually are unable to repair it completely and I am inclined to think that they just don’t want to fly it. 
 
The Hayabusa Ki-43i was crated and shipped to Australia in December 1945 to the War Department where it remained in a dismantled state at Richmond, New South Wales, until it was offered to the Australian War Memorial Museum in Canberra and accepted on 14 July 1949. Due to lack of space, the War Memorial Museum sold it to R.G. Curtis, Sydney, N.S.W., in 1953. From 1962 until1980 the Oscar had another owner, Sid Marshall, who stored the aircraft suspended in his hangar at Bankstown Airport, NSW. In 1980 a new owner was found for the Oscar, Jack Davidson of The Oaks Airfield, NSW and five years later the aircraft was sold to Col Pay of Scone NSW (1985 to 1994). 
 
Alpine Fighter Collection had for some time been expressing an interest in acquiring the aircraft and, in 1993 when Col Pay decided to pass it on, he and Tim Wallis agreed on a purchase price. The Nakajima Hayabusa Ki-43i was shipped via open container to Wanaka in 1994. 
 
The lack of overhaul manuals and technical information on the restoration of this aircraft meant that engineers often were ’blind’ with regard to correct specifications. A reasonable amount of general information on the Nakajima Hayabusa Ki-43 is available, but little on the engine specifically. In-field service manuals for the airframe existed, but because damaged items were generally replaced these manuals did not go into any great detail.  
 
Most of the restoration was done using before and after photographs and ultimately common sense. An enormous number of photographs were taken before and during the entire programme. Often ’before’ photos were later used as manuals to reconstruct as original build ups. 
 
The first requirement was to prepare an inventory and familiarisation of all components that arrived with the aircraft. Working using the inventory as a guide, the aircraft was methodically gone over and sketches, notes and measurements taken of original markings, bullet and shrapnel damage. The Oscar carried a lot of combat damage, both repaired and unrepaired, but also had some damage which appeared to be post war, through lifting and moving and it was decided that this type of non war-related damage should be corrected. It was decided that shrapnel damage which required repair was to be done as original in-field repair. Genuine fabric repairs over bullet holes were carefully removed, catalogued for historic purposes and later replaced. 
 
A world wide search was instigated for various missing items such the telescopic gun sight and several instruments. We were to be very lucky eventually and with the assistance of private collectors and museum contacts managed to obtain 80 percent of what we required. 
 
For some years, whilst a resident of Australia, the Oscar had dwelt outside. A major concern of the Department of Conservation was the thorough removal of foreign matter such as bird nests in the wings. These were extracted from internal bays in the aircraft using a vacuum cleaner directly into a large sealed contamination drum. 
 
Due to the considerable length of time since some areas of the Oscar had been touched (eg fuel tanks and inspection panels) some original hardware had seized. Most of the screws, soaked with fine lubricating oil for a few days were then easily removed using an impact screw remover.  
 
Identification of missing hardware and sizes was necessary. The majority of screws were 4 and 5mm airframe screws in old metric thread profile. We eventually managed to locate taps and dies in New Zealand and the screws themselves were sourced from Japan. 
 
In some areas such as the spinner, the original magnesium rivets which suffer aging fatigue were replaced with modern rivets to reduce any chance of failure. 
 
We had also compiled a list of work which was to be carried out by other specialists. Largest item in this list was the engine which was dismantled from the airframe at the very beginning of the project so careful documentation and photographs were required to ensure the correct buildup would be done for its later reinstallation. This time spent recording the details was to be invaluable later in the year - essential groundwork in any restoration project. 
 
Before proceeding with the dismantling of the aircraft, the airframe was waterblasted to remove dust and dirt accumulated over the years and a thorough internal search was conducted using a magnet to remove "floaters". The items retrieved this way were miscellaneous hardware, knobs off avionic equipment, washers etc, all lodged  
around in the interior.  
 
A full surface corrosion removal was undertaken. Fortunately corrosion had not got a good hold on this aircraft and most was buffed off using Scotchbrite buffing wheels. The wash also brought the internal corrosion proof paint up beautifully. The colours inside now were brilliant green with some blue panels, and where it had not been exposed to ultra violet light, had proven itself to be extremely effective in its performance. The interior skins were remarkably well preserved. We were able to duplicate the colours fairly accurately and decided that a deoxidene and alodeine wash would be appropriate before any new paint application to ensure future preservation of the original skins. Later in the year areas which did show surface corrosion were buffed to remove corrosion and the above washes were applied before the final paint. 
 
The first major items tackled for restoration were the undercarriage and brakes followed by the tail wheel which provided one of the many ’wins’ in the course of the Oscar’s restoration. The unserviceable bearings showed, after cleaning, the part number NSK 30305. The same numbered part was found still to be available off the shelf. Special tooling was manufactured to undo and later re-tighten the brass retaining nut in the undercarriage. It was fortunate for us that the Japanese manufacturers had recorded component numbers in English as well as using the old Japanese language descriptions.  
 
Over the period of restoration we gained a limited understanding of Japanese such as the date system used during the reign of Emperor Hirohito and the symbols used for above, below, middle, right and left hand. Often a Japanese visitor to the Fighter Pilots Museum next door would suddenly find him or herself translating some part of a manual needed to clarify something we were working on. Hiro, The Helicopter Line’s interpreter in Auckland, undertook a great deal of this work, as well as translating the Hayabusa song. 
 
From the tail wheel we moved on to the fuel tanks and bays. Because the Oscar was to be a taxiable static it was decided that only one fuel tank needed to be operational. The tank worse for wear was chosen because we felt this would give us an indication of the condition of the remaining tank should the decision be made to fly the aircraft at a later stage. 
 
The canopy rework began with removal of the original perspex. Several repaired bullet holes in both front and rear canopies were evidence of some close calls during the war. 
 
Removal of the cowlings and cowl flap assembly from the engine was next, as these formed part of the airframe and would remain in Wanaka. Each cowling and nacelle was numbered and recorded which told us that the aircraft had been kept serviceable by using components in this engine area from other aircraft  
 
At this stage the engine was stripped of all components not required for the actual overhaul and was sent off to Aero Tech in Auckland for rework. As it had not turned over for 50 years the internal condition was an unknown quantity and we all had our fingers crossed that its condition would be conducive to overhaul. We were to discover that it was in fact remarkably well preserved, the indications being that it had done very few hours since new. This theory was confirmed when in August we were visited by Mr Yamaguchi, one of the servicemen photographed with the Oscar on its ’discovery’ in 1945. 
 
The flap bays were now reworked. As mentioned before, one of the main manufacturing objectives of the Ki-43 was the reduction of the aircraft’s weight to an absolute minimum for improved performance, The extensive use of fabric around the flap bays and lightening holes in the internal ribs contributed towards achieving this.  
 
Removal of skins on the right side revealed that the Oscar had sustained substantial blast damage and had had a sufficient but hasty in-field repair done to keep it operational. The upper and lower surfaces had been lockwired together and a patch riveted over. 
 
Inside the flap bays, the corrosion inhibitor again had served the Oscar well, the translucent green protecting against deterioration and this required no rework at all apart from cleaning. It is of interest to note that internal skins inspected were hand numbered 750, from time of manufacture as were the fuel tank bays. 
 
Serial numbers were recorded on the engine cowls and cowl flap from which we deduced that the only original 750 parts of the entire front were the air filter and air intake box. We again suspected that the Oscar had suffered severe damage to the front, another theory which was later confirmed by Mr Yamaguchi. 
 
Before restoration commenced, original JAAF markings were clearly visible, along with what appeared to be a lightning flash on the tail. Research into this revealed that this was the insignia of the 11th Sentai. Also visible were three chevrons behind the rear canopy. Our research was inconclusive as to the meaning of these and they were to be a riddle for a few months yet. 
 

oscar001 The bare bones - the stripped Oscar in the Alpine hangar.

Unfortunately, because the aircraft had been, paint stripped in Australia many years before, no paint flakes were visible on the chevron outlines. Other parts still had original paint flakes remaining however, and prior to restoration paint samples were collected from each area to ensure as much original evidence was recorded and saved as possible. This paint research and colour matching continued throughout the restoration programme. We made a decision to paint the aircraft in lacquer to enable an adequate flattening agent to be used and to keep the appearance in the era in which the Oscar was constructed. It is important not to overglaze the paint and ruin the historic appearance of the aircraft. 
 
A widely held theory that this aircraft was actually two different aircraft which had been put together some time since the war, probably evolved because in the main, the forward fuselage and wing sections had not been paint stripped. Through identification of serial numbers we were able to disprove this notion, but it is easy to understand how such theories come about.  
 
We also thought the rear exit door was from another aircraft, as it was painted cream and visually did not tie in with the rear fuselage bare metal. However once we had stripped the rear exit door, which fortunately for us had escaped the early paint removal in Australia, we found the remains of the Hinomaru quarter, with white band and green paint flecks of what was to be the main colour of Hayabusa 750. Research indicates that aircraft with a white band encircling the Hinomaru on the fuselage normally had a dark colour scheme. The Oscar now fitted this evidence, tying up the rear exit door with small amounts of green found elsewhere on the body. 
 
The aircraft also carried the serial number 750 forward of the tail plane and slightly lower. Research confirmed this was a standard position for serial numbers of Japanese aircraft. The main gear upper pivot steel stubs in the wings are stamped also. 
 
Another major find confirming the main colour (green) of the aircraft was discovered. The butterfly flaps (combat flaps) had at some stage in Australia been covered with modern Ceconite. Removal of this Ceconite to enable rework exposed the original fabric still intact in the main and in the same green as flake, removed from the rear exit door and fuselage. Because this fabric had been protected over the years with the Ceconite, a cutting agent was rubbed on the original paint to remove oxidisation providing a larger sample to ensure that the colour match was more accurate, Because the original fabric had been torn, which is probably why someone had recovered them in Ceconite, the flaps themselves required some rework. The original fabric was carefully removed before rework and refabricking was undertaken in the same fine linen material as we had used for the rudder. These butterfly flaps are one of the more significant features of the Ki-43’s, enabling very good manoeuvrability - the difference between them and normal landing flaps being that they could be extended in action resulting in a tighter turning circle. 
 
We were to discover later, during the visit of the veteran Hayabusa pilots, that this superior manoeuvrability of the aircraft endeared itself to its handlers, especially during dog fights. The praise these veterans still showered on this aircraft after all these years was proof of its uniqueness. Against the Ki-43 was, as mentioned earlier, its poor armament. The unity of the aircraft and pilot obviously was an important factor to the safe return of both to base. 
 
It was at this point that we conducted the full surface corrosion removal over the entire aircraft. Some rework on the firewall was necessary. It was done as infield repairs, this being consistent with other combat damage. Cleaning and light buffing was all that was necessary on the wing tips, they having already been reworked at some earlier time in Australia. Also round this time Alpine’s chief engineer, Ray Mulqueen, visited Australia and returned with a compass, engine primer, vacuum regulator and hydraulic pressure gauge which were reported to have been from Ki-43 Type 1. They corresponded with schematics and photographs, fitting into the appropriate spaces in the instrument panels. 
 
The Oscar was missing several inspection panels, the oil tank and one of the machine gun pressed inspection panels forward of the front canopy. The oil tank was made solely from measurements of support straps which were still attached to the engine mount lower cross frame and research found only one diagram and one photograph of the top of a tank from which to work. We were unsure of the space available for the tank to fit as the engine was not installed for accurate measuring. It turned out the oil tank was 10mm too deep so a small depression was required to accommodate satisfactory clearance for the propeller governor. We were not able to check the tank fitment until the final hour due to the engine and mount assembly being at the other end of the country and were greatly relieved to find it required no other adjustments. 
 
These items were outworked by Ray Larsen in Queenstown then sent to Air New Zealand in Christchurch to be heat treated. Leading edges, wings, tailplane, brake and rudder pedals, fuel tank assembly, ailerons, flap bays - part after part was removed, cleaned and restored, some almost from scratch. Much assistance was given elsewhere - Colin Smith in Mandeville helped with fabric, Wanaka tradespeople offered a wide range of skills and equipment. A local dentist provided minute buffing wheels and polishers to get right into the corners of the cockpit, an area of confined space with many ribs and extrusions. Every component possible was removed from this area. Pipes for air, hydraulic, fuel and electrical conduit - originally colour coded by the manufacturers - were photographed to ensure that on re-assembly these went in exactly as they came out. Once removed they were cleaned, checked for leaks and general deterioration, found all still serviceable, repainted in appropriate colours ready for re-installation. 
 
Electrical junction boxes and the main switchboard, controls and instrument panel mounts were disassembled. The main fuse junction board still had base plates for fuses, and the bottom fuse access door. The upper panel of switches and AMP volt meter gauges was missing however and required remanufacture. Fortunately two original switches arrived from Canberra War Memorial Museum and we were able to replicate these to replace the missing ones.  
 
Information was scarce on some of the cockpit area build up and thorough research was done to get a full picture, ie. what gauge went where. Hayabusa technical literature recorded that the Type 1 buildup was "install where space permits" and this was correct. The fuel gauges are located on the right hand side by the pilot’s leg just off the floor. We were unable to locate original radio equipment so 750 remains without this feature. Perhaps one day an original system will surface and be installed. Fuse and circuit boards were rewired and installed. 
 
As the tyres which came with the Hayabusa on delivery to New Zealand had perished beyond safe taxiing operation, new ones were required. To enable retraction into the wheel well, we used McCreary 6.50-10 8 ply rating with a straight rib tread. 
 
With completion still several weeks away it was time to attend to the small cosmetic items such as the missing pad off the headrest and the pilot’s pull - a long plaited cable which hung outside the cockpit on the left hand side while the aircraft was on the ground, to enable the pilot to grasp and haul himself up the trailing edge of the steep wing. A Christchurch whip manufacturer was contacted and the severely deteriorated original sent to him for remaking. 
 
Work continued on the cockpit area, to the stage where no more could be done until the engine arrived back. Gauges could not be connected, nor could fuel and hydraulic lines. As the engine was due at any time, attention went to the firewall build up and riveting of wheel well nacelles. The rear fuselage was built up with the horizontal stabiliser, elevators, trim tab and rudder. Minor adjustments were made after check fitment and a partial root fairing was made and spliced to the original undamaged left hand side. Cables, new and original, were fitted to the controls and bunched at the front ready for connection to appropriate quadrants in the cockpit area once the front and rear fuselage were knitted together. 
 
The tail wheel canvas boot was fitted and the entire rear section of the aircraft was completed ready for painting. The ignition harness was the first part of the engine to arrive back along with the exhaust stacks, neither of which had been touched. Lack of time had prevented the overhaul shop from attending to these so work began on them as soon as they arrived. 
 
The exhaust system required a complete rebuild. At the ceasefire, the exhaust stack had not been completed and all the spares which would have been used in 1945 were in an accompanying box. These were all individually serial numbered as were most of the components we had worked on. Construction of the exhaust was underway and was to take nearly two months to complete. Some original stubs have been used, but in the main the buildup is new. 
 
The ignition harness was also a major undertaking. Original nuts were soaked in CRC and heated as they had seized over the years. Once loosened off, a diagram was drawn up of the harness and each wire multimetered. Only half of the individual wires reacted, due to internal breaks but what did register was coded on the diagram. The old wires were then crimped to a smaller diameter wire and pulled through. Initially it needed two people to drag the old wire through the bunched and melted together buildup inside the harness frame - however it got easier as more came out. 
 
New Prestolite ignition wiring, once woven through the frame, was multimetered again and the diagram completed and rechecked. This methodical approach to the rewiring of the harness, plus the diagram drawn up, was to be invaluable later for the timing to the magnetos. While battery and cockpit wiring was continuing we were able to locate some more instruments from a private collector in Australia and from the Canberra War Memorial Museum. Tim flew to Australia with our exchange items and collected the desired instruments. Among the items Tim brought home we were especially thrilled to have acquired the telescopic gun sight, a very visible part of this aircraft. Arrangements were made with Borrows Jewellers in Dunedin to restore this and the clock to working order. 
 
Looming for the electrics now extended through the firewall, but as yet the engine was not ready. We decided to knit the front and rear fuselage together permanently. A forklift was used to raise the front span of wings and cockpit up to engage with the two parts and Oscar 750 was then put on to jacks to enable retraction of the undercarriage and adjustments to be made to the rigging. A film crew from Japan was scheduled to arrive in the next few days so we fitted the canopy and other finished components to ensure 750 looked as complete as possible for the filming.  
 
The engine arrived only hours before the film crew. It was uncoated and positioned to the airframe via a block and tackle. The exhaust system was still under construction, and the oil pipes, starter, magnetos had not come back with the engine, however we did as much as we could for the filming. 
 
The Japanese film crew brought with them a man who was able to help us greatly with our research into the Oscar’s history. The photograph taken by a RNZAF photographer when the Oscar was discovered in Rabaul in September 1945 had shown three Japanese servicemen beside the plane. The Japanese television company, having searched for some time for any of these three men, had identified and located Mr Yamaguchi. Mr Yamaguchi journeyed back to Rabaul with the film crew then on to New Zealand, where he was reunited with Denys Hamilton and Hayabusa Ki-43 750 in Wanaka. Mr Yamaguchi was able to confirm some of the earlier assumptions we had made based on evidence uncovered whilst restoring the aircraft. As we had suspected, the engine and propeller change had been due to a bad landing. This rebuild had not been completed fully at the time of the ceasefire and was the reason why the Oscar was not flown to Jacquinot Bay along with the other aircraft. Mr Yamaguchi, although not part of the 11th Sentai, but serving with the 14th Army Repair Depot in Rabaul, did recall that the colour scheme of 750 was as we had deduced, but he told us that it also wore camouflage brown. He was not able to remember what colours the chevrons or lightning flash originally were, so we relied on our samples for the flash, and used white for the chevrons, believing that further information would eventually surface regarding this as indeed it did. 
 

oscar002 The Oscar, Sakae engine to the fore, and resplendent in the NZFPM. Restoration team member Jan Bullock stands on the wing root of the worlds best example of of a Nakajima Ki43i.

The excitement of Mr Hamilton and Mr Yamaguchi’s visit passed and once again we were hands on to the restoration. The items temporarily placed for filming were removed and put aside for final assembly. The engine installation of propeller governor, generator, oil drain valve, fuel valve, ignition harness and oil cooler commenced. The pipes and hoses also arrived and the engine assembly was completed. 
 
The next major problem was establishing the firing and timing order. As we lacked the necessary information, a Wright 14 cylinder radial engine manual was consulted. The ignition harness diagram and a magneto diagram was drawn up and worked on paper before we converted the line up to the Wright cylinder line up. We discovered that the Japanese Ha-25 14 cylinder engine was five cylinders out compared to the Wright and this clarified the procedure. However we would not be absolutely certain until the engine actually fired. As it turned out, the methodical approach, however basic, proved correct - a real win we felt. A special tool was made up to lock the propeller into position with a locking torque of 720ft/lb.  
 
The final components to arrive were the magnetos, the left hand arriving three days before the right, allowing us time to study this on the bench before installation. Once the right magneto arrived, it was a straight forward procedure to wire in each lead and test individually to the spark plug using the multimeter. The wiring of the electrical charge system, fuel pump and starter vibrator was completed with protective fuses to each system, using the original switches for these controls. 
 
The combat flaps and system required re-rigging the cables to parallel the flaps in retract position, the ram refitted and hydraulically tested. Good results, so lockwire and split pins were fixed, completing this system. 
 
Wing tips were screwed on and inspection panels fitted including underbelly fuel inspection panels. A further check located a couple of tired rivets which were replaced. 
 
The throttle control and governor control were connected up and rigged and the carburettor air box fitted. The filter/unfiltered air door was rigged. Special tooling was made to enable the main landing gear oleo to be filled using this charge valve. The pitot tube, made in- house, was installed along with the moisture trap and hooked up to the  
pipes in the leading edge of the left wing outer and tested. 
 
Finally the aircraft was ready for external paint application. On the next still day, a Saturday, we pushed Oscar outside and applied deoxidene and alodeine, treatment for anti corrosion and preservation. The aircraft was left inside to dry on Sunday and on Monday we began masking up. Etch was applied to provide a good adhesive for the paint and aluminium to marry. First paint applied was the undersurface grey with flattening agent mixed at 10 percent, next was the army green top main colour, followed by camouflage brown. Each application required masking, removal, more masking and finally the replacement of the Oscar’s original markings according to measurements taken before restoration had commenced - first the lightning flash of the 11th Sentai on the tail then the wing and fuselage Hinomarus and finally the chevrons. Last to be applied was the anti- glare forward of the canopy. Those chevrons. Unable to identify their colour or significance we had painted them white.  
 
The visit in September of veteran Japanese Army Air Force personnel and other interested parties solved the riddle for us. One of the veterans had actually served with the 11th Sentai although based elsewhere. He told us that the chevrons meant that our Oscar flew in the third flying position (three chevrons - 3rd - yellow), of the 11th Sentai’s 2nd squadron (red lightning flash). The chevrons were repainted yellow the next day. 
 
First engine run after 50 years was rapidly approaching - the pilot’s seat was installed, left until the last to provide easier access within the cockpit. The 21st of September 1995 was a day for all at Alpine to remember. Initial preparation before start was to prime the engine with oil and crank it over without spark plugs fitted. This was done and an oil pressure of 45psi was obtained after 15 seconds of cranking. Fuel pressure also gave a reading. The spark plugs were all connected and tightened, final assembly checks done and Nakajima Hayabusa Ki-43i - serial number 750 was pushed outside and filled with 100 litres of fuel. The plane was chocked and the rear fuselage tied down. Everyone took positions, fire extinguishers on either wing, cameras were ready, Doug James, test pilot at last after all those months as engineer, climbed in and carried out the necessary checks, after the propeller was hand turned. The signals from the pilot were given, the carburettor primed and start switch hit. The propeller spun and stopped - another try and the engine fired again and died. Not enough fuel - another prime. This time the engine accepted the challenge and united itself in a crisp rumble which could be heard all over the airfield. Hayabusa Ki-43 No. 750 - the Oscar - has entered another chapter of its own history."