The Ki-43 Type 1 Hayabusa
(Peregrine Falcon) was the most widely flown fighter of the Japanese
Army Air Force during the war (Allied code name Oscar). Entering
squadron service shortly before the Pearl Harbor attack, the Oscar was
highly manoeuvrable with a good rate of climb, but somewhat underpowered
and, despite updates, unable to compete effectively with U.S. fighters
in the latter stages of the war.
An official USAAF analysis, however,
described later models as "an increasingly dangerous
opponent." The Oscar saw combat in all Pacific areas where the
Japanese Army conducted air operations, and most Japanese Army Aces
scored most of their kills in this aircraft. At the end of the war the
Oscar was employed with the Army's Taiatari (suicide) units.
First flown in Jan. 1939,
the Oscar was designed by Nakajima engineer Hideo Tonkawa. Army pilots
initially disliked the fighter, which they found less manoeuvrable than
its predecessor, the Ki-27 Ante. The Oscar was modified, primarily with
a "butterfly flap" that was extended in combat to provide
additional lift, increase turn rate, and improve control response. The
Oscar remained in production throughout the war. Only forty Oscars were
in Army service at the time of Pearl Harbor. A more-powerful engine and
other features characterized the Ki-43-II, put in production in 1943 and
the Ki-43-III, produced from Dec. 1944.
production totalled 5,919 units.
The Oscar was also flown by the Thai Air Force. (After the war they were
also flown by Indonesians against the Dutch, and briefly, by the French
in the Indochina (Viet Nam) conflict.)
The Oscar was a simple,
streamlined aircraft; the radial-engine, low-wing aircraft resembled the
A6M Zero and to some extent Western fighters. It had a bubble canopy and
was one of the first Japanese fighters to have armour; later models were
also fitted with protected fuel tanks.
The major production
variant, the Ki-43-II, had a maximum speed of 329 mph, which was
increased in the IIIa to 358 mph. Normal range for the II was 1,095
miles, extended to 1,990 miles with a drop tank, reflecting the Japanese
interest in long-range fighter operations.
Most aircraft had two
12.7-mm machine guns, making them highly under gunned by Western
standards. The IIIb variant, of which only two prototypes were produced,
instead had two 20-mm cannon. The II and III variants could carry two