Kokusai Ki-105
| Kokusai Ki-105 | |
|---|---|
|
|
| Type: | Transport plane |
| Design country: | |
| Manufacturer: | |
| First flight: |
December 15, 1944 |
| Production time: |
1945 |
| Number of pieces: |
9 or 10 prototypes |
The Kokusai Ki-105 Ohtori ("Phoenix", allied code name Buzzard (?)) Was a twin-engine Japanese transport aircraft of the Army Air Force from World War II . The first flight took place at the end of 1944.
history
Cargo glider Ku-7
In February 1942, the Japanese Army Air Force formally requested Nippon Kokusai to develop a heavy cargo glider . The name for this was Ku-7. The transport capacity was required for a Mitsubishi Ke-Ni Type 98 light tank or a 7-ton truck. The glide ratio should be at least 1:20 and the rate of descent should not exceed 2 m / s. A twin-engine bomber was to serve as a tow plane. The materials used were steel and wood in order to largely save aluminum.
The first studies already showed the advantages of a design with double tail girders and a central fuselage nacelle. Above all, the good loading option via a tailgate played a decisive role. The construction work was finished in December 1942.
Under the direction of chief designer Kozo Masuura, the company, which by then had developed planes that were no more than half the size, decided to first build an airframe called the Ku-7-I for static load tests. These were carried out between January and March 1943. Construction of the first airworthy prototype (Ku-7-II) began in June 1943 and was completed in July 1944. During the successful maiden flight on August 15, 1944, a pre-production Mitsubishi Ki-67 was used as a towing machine . The subsequent testing of the machine, which was given the name Manazuru ( white-naped crane ), went without any major complaints.
Early on in the development of the Ku-7, the Army ordered 300 Ku-7-IIs, which were to be delivered by March 1945. It was assumed that by then a suitable bomber would be available for towing. Investigations were carried out by the 1st Army Arsenal, whereby both the Nakajima Ki-49 -IIa Helen and the Mitsubishi Ki-67 Peggy were tested. However, the Ki-49 failed because it did not prove itself in use as a bomber and production ended in January 1945. A division of the successful bomber Ki-67 between bomber and tow units was seen as impossible, so that the production of the Ku-7-II was abandoned.
Ki-105
As early as the summer of 1943, the army had suggested motorizing the Ku-7-II and thus saving the towing machine. Work on the redesign of the aircraft, known as the Ki-105 Ohthori , began in early 1944, but further development was delayed until the successful maiden flight of the Ku-7-II. After that, the army changed the order to build 300 Ku-7-IIs into 300 Ki-105s. The second Ku-7-II prototype was quickly converted into the Ki-105 prototype. The biggest modification concerned the extension of the tail boom in the front area up to the wing leading edge and the installation of two Hitachi-Ha-13-Ko radial engines with 450 HP each . The fuselage remained largely unchanged, apart from additional seats for radio operators and flight engineers in the cockpit.
The first flight took place on December 15, 1944, whereby the flight characteristics were assessed as good, but the performance of the engines was seen as unsatisfactory. Accordingly, a more powerful Mitsubishi Ha-26-II, each with 940 hp and Hamilton standard three-bladed propellers, was converted. The order for large-scale production was awarded to Kokusai's plant in Kyoto. It was hoped that the Ki-105 could be used in large numbers in the spring of 1945 for releasing troops and transporting supplies to Okinawa . The low production rate and the increased bombing by the Allies prevented this. At the end of the war, about 50 copies were in final production; nine or ten machines had already completed the acceptance flights.
Fuel transporter
The Ki-105 was also intended to be used as a desperate attempt by Japan to break the Allied blockade towards the end of World War II. The plane was supposed to transport urgently needed fuel from the oil fields in Sumatra, which are still under Japanese control, to Japan. In order to fulfill the intended purpose, the "Ohtori" needed a range of 2500 km. To achieve this, the engines had to use 80 percent of the charged fuel. Then there were the empty flights to Sumatra. The chances of the big, slow and clumsy bird - fully laden with aviation fuel - even survive a flight is another matter.
Technical specifications
| Parameter | Ku-7-II | Ki-105a |
|---|---|---|
| crew | 2 | 4th |
| Passengers | 32–40 soldiers | |
| length | 19.93 m | |
| span | 35.02 m | |
| height | 5.56 m | |
| Marching speed | - | 220 km / h |
| Top speed | 296 km / h | |
| Max. Takeoff mass | 12,000 kg | 12,500 kg |
| drive | - | two air-cooled radial engines Mitsubishi Ha-26-II; 940 PS (691 kW) each or two Ha-102; 1,080 PS (794 kW) each |
Similar developments
The further development of gliders to motorized transport aircraft was initiated by German manufacturers in the early 1940s. In the following years this concept found acceptance in other countries as well as in Japan.
| Year of motorization | Glider | Powered aircraft |
|---|---|---|
| 1942 | Gotha Go 242 | Gotha Go 244 |
| 1942 | Messerschmitt Me 321 | Messerschmitt Me 323 |
| 1945 | General Aircraft Hamilcar | General Aircraft Hamilcar Mk.X |
| 1948 | Chase CG-18 | Chase C-122 |
| 1950 | Chase CG-20 | Fairchild C-123 |
See also
literature
- Giuseppe Picarella: Moving the empire Part 2 - Troop gliders & transports . In: Airplane Monthly March 2004, pp. 36–41
- Jim Winchester: The World's Worst Aircraft . ISBN 1-84013-752-5 , p. 136
