Kayaba Type 4 “Katsuodori” Ram-Jet Fighter by Meng

1/72 scale
Kit no. DS-001
Cost: $15.99 (@ spruebrothers.com)
Decals: Two versions – Imperial Japanese Army and Imperial Japanese Navy
Comments: Engraved panel lines; includes two complete kits


The Kayaba Katsuodori ramjet fighter was a concept plane that never made it off the drawing boards during World War II. It was the most advanced of the Kayaba family of tail-less aircraft which dated back to the 1930’s. The Kayaba series of gliders (Ku-1 through Ku-3) were developed with the sponsorship of the Imperial Japanese Army and were designed to investigate the feasibility of flying wing or tail-less combat aircraft. The Katsudori, designated Ku-4, like its glider ancestors featured a swept wing, and minimal vertical tail surfaces located at the outer edge of each wing. Unlike its predecessors, it was to be powered by a pusher engine. It was designated Ku-4 despite the fact that the “Ku” nomenclature was reserved for gliders. This may have been a deliberate attempt to protect what was likely a top-secret project: a jet- or rocket-powered flying wing fighter.

The Kayaba Katusuodori flying wing design was completed by April 1940, and the all-metal construction of the prototype was finished some months later. But the Imperial Japanese Army’s support withered after a Ku-2 glider crashed on May 10, 1941 at the Tachikawa airport and was damaged beyond repair. Funding for the Katsuodori project evaporated. Within months, the Pacific War began when Japan launched a sweeping attack throughout Southeast Asia, and made a pre-emptive strike against the U.S. Pacific Fleet at Pearl Harbor, Hawaii. With the coming of the war the Japanese Army focused on the production of conventional combat aircraft, and lost interest in many experimental types, including the Kayaba Katsuodori. At war’s end, the Allies discovered the blueprints for the Ku-4, and discovered that it was to have been powered by a ram-jet, based on the German HeS001 Type A design. Armed with two 30mm cannon in the nose, the Katsuordori had limited range, and was to have been released against American B-29 formations from mother ships such as Nakijima’s Ki-67 “Peggy” or G8N “Rita” bombers — much as the Ohka rocket-powered Kamikaze weapons were — with the key difference that the Katsuodori was intended to return from its mission. Given that it never entered production, it qualifies as the Japanese version of a Luft ’46 aircraft.


Type: Single-seat swept wing tail-less fighter
Length: 4.48 meters
Height: 1.85 meters
Wingspan: 8.99 meters
Armament: Two nose-mounted 30mm cannon
Powerplant: Four license-built HeS001 ram-jets

The Kit

New from Meng of China is the Kayaba Katsuodori ram-jet fighter. The most notable feature of this kit is that is contains parts for two complete aircraft, which is convenient for those modelers who wish to build both the Imperial Japanese Army and Imperial Japanese Navy versions (decals are provided for both). The instructions are clear and well-illustrated, with a helpful paint guide that is unfortunately limited to Hobby Color, Mr. Hobby, and Vallejo paint numbers. Parts for each aircraft are on a single sprue, with each sprue contained in its own unsealed clear plastic bag. The kit is molded in grey and bears engraved panel lines, as well as crisp demarcations for the control surfaces on the wings and small “tail-ettes” located at each wing tip. The main virtue of an otherwise basic cockpit is the raised detail on the dimunitive main instrument panel. A basic seat and control yoke are provided, but there is no sidewall detail. However, most of the interior surface of the fuselage appears to be textured, which should facilitate painting. The injection molded canopies — sealed in their own clear plastic — are each a single, frameless part, so there is no need for masking.

The kit appears to be a simple yet high quality mold marked by ease of construction: the intake and jet exhaust assemblies consist of two parts each, with the cockpit assembly comprising five. With all three assemblies complete, it is time fo cement on the one-piece wings and tail-ettes. The fuselage itself is small, tubular, and slightly bulged, reminescent of the British Gloster Pioneer. The ram-jet assemblies, a four-piece loading dolly and landing gear are next. The ram-jets are not solid parts, but sport precision-machined openings for their exhaust nozzles. They are attached to the aircraft by means of a one-piece rectangular frame.

Each of the landing gear is a simple two-piece affair consisting of a V-strut and a wheel. They appear to be fixed gear, as there is no evidence of gear doors among the nicely done engraved panel lines on the fuselage, but based on the box art it appears they were jettissoned during flight, with the little fighter making a belly landing once its work was done. Given what had to be limited fuel, the concept may have been for the Katsuodori to make an unpowered glide back to earth — which could explain the cancellation of the project following the Ku-2 glider crash, particularly if there were fatalites. There is limited information on this type, as it never entered service. Parts are provided for attaching the Katsuodori to a larger mother ship.

The decals are produced by Meng and come sealed in their own clear plastic bag. They are thin and appear to have a matte rather than a glossy finish.  They are provided for either a Navy aircraft with a paint scheme of overall Imperial Japanese Navy grey; or an Army aircraft with a camouflage scheme of Imperial Japanese Army grey overall with IJA green splotches on the upper surfaces.


This an interesting kit of some historical note that should build up into a striking and unusual jet fighter. Ideally it would include an actual ram-jet engine with an option for an open panel or two, and an option to have the cockpit open or closed. But what is provided in the kit should make for an entertaining build with one or two detailing opportunities. Highly recommended.


  • “Japanese Flying Wings” by E.L. Wooldridge
  • Meng Kayaba Katsuodori instructions
  • www.wikipedia.org
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