Staff Writer (Updated: 9/3/2015):
The Ki-61 became a design reality by 1940 and was the brainchild of Shin Owada and Takeo Doi. Their previous design experiences saw them working under German aircraft designer Richard Vogt and the German influence in the Ki-61 could readily be seen to the aviation-educated eye. Additionally, the German mark on this series of aircraft was made ever moreso with the inclusion of a license-produced Daimler-Benz DB 601A which were being fielded under the recognizable Japanese label of Ha-40 under the Kawasaki brand. The prototype would be ready to fly by 1941 with full production beginning in 1943.
From an external design standpoint, the Ki-61 featured a sleek and slender fuselage design. The engine was placed well ahead of the cockpit, with the latter being situated in the center-forward position of the upper fuselage. The wings were of a monoplane low-mounted type with rounded edges, as were the horizontal and vertical tail surfaces adorning the empennage. Power was derived form a single Kawasaki V-12 piston engine, offering up performance statistics including a 367 miles per hour top speed, a 16,404 foot ceiling limit and an equally impressive 1,118 mile operational range. To the trained observer, the Ki-61 definitely shared some similarities to other nation aircraft designs, almost always compared favorably as a meshing of the German Messerschmitt Bf 109 and the American North American P-51 Mustang. The nose design could easily be associated with either design, as can the placement of the cockpit, smallish tail section and the under-fuselage scoop.
The Ki-61 proved a worthwhile platform in service through to the end of the war. The system was actually one of the few Japanese aircraft to be able to engage the Boeing B-29 Superfortress at its normal operating altitude and was capable of handling it with some power thanks to the Hien's powerful 4 x 20mm cannon array. Joining the ranks of capable fighters in World War 2, the Kawasaki Ki-61 Hien certainly is a worthy mention in any discussion - at the very least earning the title of one of the better Japanese-branded fighters of the conflict. Some 3,000 Hiens in various forms were produced.