engine. One German made Mauser MG 151/20 20 mm cannon was housed in a weapons bay in each wing. With a normal loaded weight of and a gross wing area of the wing loading was 181.76 kg/m2 (37.23 lb/ft2), which was extremely high by Japanese standards (the standard IJAAF fighter, the Ki-27, had a wing loading of 70 kg/m2 (14.33 lb/ft2)). From the start of flight testing it became apparent that the design was seriously flawed in several key areas. The take-off run was unacceptably long, while in flight the aircraft displayed some lateral instability, excessively heavy controls and poor control response. The spinning characteristics were described as "dangerous" and the stalling speed was extremely high. Although a top speed of had been projected the Ki-60 was only able to achieve . As a result, the second and third prototypes, which were still being built, were hurriedly modified in an attempt to mitigate some of the more undesirable traits. Approximately were removed, primarily by replacing the MG 151 cannon with Ho-103 machine guns. This reduced the normal loaded weight to . Coupled with a slight increase in wing area to , this resulted in a slightly lower wing loading of 169.7 kg/m2 (34.76 lb/ft2). Detail changes were made to airframe sealing and to the contours of the air intakes and radiator bath. Flight tests were still disappointing, with both of the modified prototypes displaying most of the shortcomings of the first. A top speed of only was reached, with a climb rate still well below specifications. By this time the Nakajima Ki-44, which had also been designed as a dedicated interceptor, was beginning to show some promise and the Koku Hombu selected this in fulfilment of its requirements. From early 1941 the full attention of Takeo Doi and Shin Owada was focused on the Ki-61; the Ki-60 became important in that the Ki-61 design was able to be improved using the lessons learned from the poor characteristics of the Ki-60. Plans for production were cancelled in late 1941 after three airplanes had been built. Specifications (Ki-60 2nd prototype) See also References Notes Bibliography Berliner, Don. Surviving Fighter Aircraft of World War Two: Fighters. London: Pen & Sword Aviation, 2011. (new edition 1987 by Putnam Aeronautical Books, .) Tanimura, Masami with Kozo Tanaka; Yuji Kishida; Makoto Oda; Yoshiharu Nakano and Saburo Kawasaki. Kawasaki Ki-61 (Tony). Blaine, WA: Paul Gaudette, Publisher, 1967.