WHAT AIRPLANE IS THIS?

The NiK2-J Shiden-KAI

The Japanese, having to plan for a war covering the vast Pacific Ocean, saw a need for a seaplane fighter to defend its far-flung seaplane bombing and reconnaissance bases. These bases were planned for small pacific atoll islands that could not support runways. They would nonetheless be vital to protecting Japan’s planned Pacific Empire as they could be put almost anywhere there was a sheltered lagoon.

The Japanese Navy first tried converting the Zero to a float fighter. This worked, but the airplane’s famed speed, climb rate and maneuverability suffered from the extra weight hanging below the fuselage. The Zero’s 950 hp engine was also somewhat anemic for a float fighter. While acceptable, the 270 mph “Rufe” was clearly an interim machine until something better came along.

That something was the Kawanishi N1K1 Kyofu (Mighty Wind) float fighter. Begun as a Japanese Navy specification for the world’s most powerful float fighter, this airplane had a powerful 1,460 hp engine that gave the airplane a top speed of 302 mph and a climb rate near 3,000 ft. / min. This was very respectable in its day and near land-based fighter performance.

In fact, the performance was so good that the Kawanishi people began to wonder if they were wasting a good airframe by putting it only on water. So as a private venture, they took one of the float airplanes, removed all the water equipment and stuffed some wheels into the wing. For extra measure the horsepower was upped to 1,990. The result was the N1K1-J Shiden (Violet Lightning).

The Shiden, with its mid fuselage-mounted, laminar flow wing similar to the P-51 Mustang’s in concept, had a top speed of 362 mph could reach 20,000 ft. in less than eight minutes. Weighing less than 10,000 lb. total and with a 40 ft. wingspan offering 253 sq. ft. of lifting area, the Shiden could outturn the Mustangs and Hellcats with room to spare.

But there were some problems. Most notable was the weak landing gear. The extra long gear required to protect the huge four-bladed propeller stretched too far from the mid-mounted wing. It broke, often. So a new model was planned that had the wing mounted on the fuselage bottom.

But as usual, once a design change is begun, everything else changes as well. The redesigned N1K2-J Shiden-Kai got a different 2,000 hp engine, a longer fuselage for a better Center of Gravity location (important in full-size aircraft as well as in models), and two extra machine guns. The K2-J was a totally different aircraft from the K1-J, sharing only its wings.

The N1K2-J was a little faster at 370 mph and climbed a little better, reaching 20,000 ft. in just over 7 minutes. But, since the K2-J now weighed only 8,800 lb., a thousand pounds lighter than the K1-J, maneuverability approached that of the famed Zero and was superior to anything the Allied Air Forces had. Its four 20 mm cannon and two 13.2 mm machine guns had devastating firepower and superior range compared to the American airplanes’ six .5 cal. machine guns.

But as often happens to the losing side, it was too little, too late and most of the manufacturing base required to produce the airplane was destroyed by American bombing efforts. Only 415 of these fine aircraft were produced and the best model, the NK9H-S that could almost reach 400 mph, never saw service.

Fortunately, this little known but very advanced propeller driven fighter is preserved at the US Air Force Museum in Dayton Ohio. In fact, the contest photo was taken on the museum ramps. You can see the airplane there.

As for the clues:
The Kawanishi N1K1 Kyofu was a float-plane fighter. Obviously this aircraft doesn’t look like it would operate well from the water. But the Shiden was the only successful land-based fighter ever built that started out first as a sea-borne machine. This one might be good for making bets at the field as few modelers would know this.

The Mitsubishi Type 52 Zero had a three-blade propeller and only one cannon in each wing. The contest aircraft clearly has four gun barrels sticking out of the wing. But there are many other airframe differences from the Zero including the Shiden’s very small elevator, four-bladed propeller and its lack of exhaust stacks surrounding the cowling that distinguished the Type 52 Zero from all other Zero models.

The Kawasaki Ki-64 had two water-cooled, in-line engines mounted in tandem inside the fuselage. Obviously, the contest aircraft is not water-cooled and just doesn’t have room for two engines. Its engine is plainly round, not an in-line one. The Ki-64 was a very strange fighter with surface wing cooling. It could reach over 430 mph but never went into production because of all the problems tandem engines experience, such as constantly catching fire.

The N1K2-J Shiden-KAI was studied at Dayton's Wright Field then restored for display in the Air Force Museum. The contest photo clearly shows a Japanese aircraft being studied by personnel wearing 1940’s era Air Corps uniforms.

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