A lightning flash

In late 1941, when Japan attacked Pearl Harbor, the technology of the Japanese military was not noticeably behind the Allies, and in some areas – torpedoes and carrier based fighters, to mention two – Japan was well ahead. However, as the war continued the Japanese proved to be totally unable to keep up with the Allies’ advances in such things as aircraft and electronics and especially radar.

There was, however, one project in which the Japanese demonstrated considerable technological acumen, the  Kyushu J7W1 Shinden (Magnificent Lightning) canard fighter – the only canard combat fighter seriously considered for mass production during World War II and one of the most futuristic-looking airplanes of the period.
On a canard aircraft, as discussed previously, there are a small set of wings in the forward part of the fuselage with the main wings in the rear of the fuselage. While it offers a number of advantages, the canard configuration was generally considered to be too unstable in pre-fly-by-wire days.

The aircraft’s unique configuration was the product of work by the technical staff of the Japanese Navy, which saw in the canard concept some significant advantages, not the least of which was the capability of easily replacing the rear-mounted radial engine with a new jet engine under development, the Ne-130 turbojet with almost 2,000 pounds of thrust.

The Navy technical staff asked for three small wooden gliders, called the MXY6, to test the moderately swept wings and the aircraft’s handling qualities at low speed.
The gliders began flight trials in the autumn of 1943 and one was fitted with a 22
horsepower four-cylinder air-cooled engine for powered tests.

The unpowered and powered versions of the MXY6 proved the feasibility of the canard configuration, and the Navy ordered the design of the Otsu (B) Type Interceptor Fighter by the Kyushu Hikoki K.K. company. Kyushu was selected despite its lack of previous experience with high performance aircraft because both its design team and production facilities were not involved in the full scale production of combat aircraft.

The Navy assigned a team from its technical staff to aid in the design and testing and work on the fighter – the Kyushu J7W1. The Shinden (Magnificent Lightning) began in earnest in June 1944. The first prototype was completed quickly in 10 months.

The Shinden was an exotic looking aircraft. It was powered by a 2,130 horsepower Mitsubishi 18-cylinder radial engine with a supercharger behind the pilot’s cockpit driving a large, six-blade pusher propeller via an extension shaft. Engine cooling air was supplied by long, narrow, obliquely mounted intakes on each side of the fuselage.

To keep the propeller off the ground it had long, stalky tricycle landing gear, so tall the average Japanese could walk under it without ducking.

The small horizontal control surfaces with elevators were mounted in the nose, and the pilot sat in the center of the fuselage, forward of the wings, which were moderately swept so the center of gravity was far enough forward to keep the propeller off the ground on takeoff and landing.

The wings also had two large vertical fins and rudders mounted mid-span and small auxiliary wheels under the fins.

An advantage of the canard configuration was that it left the nose free for weapons, and the Shinden carried the very heavy armament of four 30 millimeter Type 5 cannon with a rate of fire of 450 rounds per minute per gun. The weight of these large cannons also helped to balance the weight of the engine and propeller at the back of the fuselage.

Even before the prototype was complete in April 1945, the Japanese Navy, desperate for a heavily armed high-performance interceptor capable of attacking high flying American B-29s, decided to order it into production. It was hoped Shindens could be produced at the rate of 150 a month.

While two plants tooled up for production, the test program began in May 1945, but the engine runs on the ground showed the cooling intakes were insufficient and they had to be reworked.

By that time, Japan was under constant American air attack and remedying these faults proved difficult, and general chaos delayed the first flight until Aug. 3, 1945.
The first prototype made four flights totaling 45 minutes and showed some problems with the engine/propeller combination, mainly a hard pull to the right from excessive torque as well as vibration of the propeller shaft, but no problems with the flight characteristics.

Unfortunately for the Shinden, on Aug. 15 Japan surrendered to the Allies. Though the second prototype had been completed, it was not flown.
American Naval intelligence specialists dismantled and shipped the first prototype to the U.S. at the end of 1945 for testing and evaluation along with about 145 other Japanese airplanes.

Sadly, there is no record that anyone ever flew the J7W1 in the U.S.
The Shinden was given to the Smithsonian Air and Space Museum in 1960 and it is now in storage.

(For questions or comments, contact Dr. Michel at marshall.michel@ramstein.af.mil.)