Staff Writer (Updated: 9/3/2015):
The single-engine, one-man fighter was Japan's first monoplane design, becoming a sort of bridge from the old and new fighter development strategies. Qualities that showcased the Ki-27 to the old ways of fighter design including the very identifiable static land gears. A tail skid was still being used when the Ki-27 reached full production. At the cost of self-sealing fuel tanks, pilot protection and other aircraft amenities at the time, the Ki-27 became a nimble and fast fighter, armed with 2 x 12.7mm heavy machine guns.
In the early years, the Ki-27 enjoyed a period of success against the Chinese and Allied fighter pilots in the Pacific. As Allied fighter designed continued to improve, aircraft like the Ki-27 would begin to lose out to the advanced technologies and be relegated to homeland defense, pilot training or kamikaze use.
In the end, the decision to not protect the pilot nor his fuel tanks became the premise for the aircrafts undoing. The light and nimble Ki-27 would cease to become a factor, in much the same way that its A6M Zero counterpart did, and help the Allied make their push throughout the Pacific. Nevertheless, the Ki-27 enjoyed a long period of success when it was initially delivered and would stay a major part of the Japanese Army movements until the end of the war - albeit in limited fashion by then.