Kawanishi KX-3

History of West Sichuan KX-3

By 1943, the fortunes of Imperial Japan in many possessions in the Asia-Pacific region of the world took a turn for the worse. Its carrier forces are regularly defeated, while its submarines are constantly hunted.

Likewise, the country's merchant fleet was constantly threatened by Allied attacks in the Pacific, which meant that supplies and manpower between islands could not be effectively replenished.

As the Empire's logistical nightmare intensifies, the authorities seek solutions - as desperate as some of the ideas may seem - to avoid the total defeat of their overseas armies. To date, Kawanishi Aircraft has established itself as the premier seaplane manufacturer for the Imperial Japanese Navy (IJN) with a range of highly regarded products such as the H6K "Mavis" and the H8K "Emily".

In 1943, the IJN authorities ordered the company to build a massive 500-ton multi-engine airship capable of transporting large quantities of cargo by water to land bases across the region - and as expected, logistics would be a major focus of this beast. aircraft, the project was called "KX-3".

Up until this stage of the war, West Sichuan engineers had no similar product to draw inspiration from, so the feat was fraught with design and engineering challenges at every turn, especially how to get it to lift so large, The magnificent plane soars into the sky under its own power. The Germans managed only one flying prototype of the Blohm & Voss Bv 238, and the American Hughes H-4 Spruce Goose barely counted as a success in its short airtime.

Still, the challenge fell to the company's employees, and a team set out to draw a blueprint for the new machine. To expedite development work, the company started with the proven H8K airship and simply scaled up all dimensions to meet IJN requirements.

That means a boat-like fuselage for take-off and landing on water, and a large plane with wide spread wings -- the latter essential for providing the necessary lift and drag. The main plane was placed on the fuselage spine, with foldable outboard windows supporting huge appendages near their midpoint.

Long tube flaps will be attached to the trailing edges of both flaps to add extra lift and drag when needed.

The hull shall be provided with plate sides and rounded rear surfaces. The boat-like hull extends from under the nose assembly to the center of the tail. The tail will have a pair of high-reach vertical fins for control, supported on separate horizontal planes at the end of the fuselage.

Overall, the dimensions of the aircraft (at least on paper) amount to a length of 531 feet, a wingspan of 590 feet, and an overall height of 116 feet. At the time nothing came close to matching those specs.

Aside from the sheer size of the proposed aircraft, the main concern was the power required to fly it. This resulted in a configuration of no less than 12 Rikugun Kokugijutsu Kenkyuuju (RKK) Ne 201 turboprop engines, each producing an estimated 1,870 hp, each driving a multi-blade drawn propeller unit. To complement this, four to six Mitsubishi Ne 330 turbojets are required (technology provided by BMW of Germany). The jet engines will be housed in streamlined nacelles that are located beyond the last turboprop on each main plane.

Overall, it is hoped that this combined engine combination will provide the airship with good steam power to take off and cruise under load.

In addition to the advanced aviation aspects of aircraft, there are more traditional topics such as self-defense. In order to protect the slow, bulky aircraft from enemy fighter jets, the KX-3 is likely to follow the existing Kawaii airship in armament -- a hybrid of an automatic cannon and machine gun. While its defense kit was never completed, it is certain that the nose and tail will be defended by a single 20mm autocannon (or similar), while multiple dorsal turrets are easily mounted on the rear fuselage spine On longer lengths. Each may contain 2 x 13mm air-cooled heavy machine guns.

At the same time, similar weapon accessories will be placed on each side of the hull.

In any case, the expected development of the turboprop proved to be slow and a technical nightmare, and the slow development of the Japanese turbojet did not help. Combined with the deteriorating wartime situation in Japan and the precious resources needed to build the airship's massive fuselage and wings, the KX-3 was doomed from the start.

The program ended with little actual work done, and the war itself ended in August 1945 - ending all prospects for the Kawanishi/IJN airship project.

For now, if completed and flown as expected, the KX-3 should be the largest aircraft the world has ever seen. Instead, it went down in history as another unrealized WWII "secret weapon."

Specification

Basic

Production

Roles

Dimensions

Weight

Performance

Performance

Armor

Changes