Kawasaki Ki-100

https://en.wikipedia.org/wiki/Kawasaki_Ki-100

The Kawasaki Ki-100 was a fighter aircraft used by the Imperial Japanese Army
Air Service in World War II. The Japanese Army designation was "Type 5 Fighter"
(?????: Go-shiki sentouki or abbreviated as Goshikisen). No new Allied code name
was assigned to this type; 275 Ki-100 airframes were built as Ki-61s before
being modified to accept a radial engine in place of the original inline engine.

The emergency measure of adapting a Ki-61-II-KAI fighter to carry a Mitsubishi
radial engine resulted in one of the best interceptors used by the Army during
the entire war. It combined excellent power and maneuverability and, although
its high-altitude performance against the USAAF Boeing B-29 Superfortress heavy
bombers was limited by the lack of an efficient supercharger, it performed
better than most other IJAAF fighters.

Operational missions began in March 1945. From the first engagements, the Ki-100
performed well against the B-29 and showed itself to be equally effective
against U.S. Navy carrier fighters. A new variant, the Ki-100-Ib, was produced
during the last weeks of the war in time to equip five sentai for home defense
duties.

The army general staff was amazed by the flight characteristics of the plane,
which surpassed the Hien's in all but maximum speed (degraded by a maximum of 29
km/h [18 mph] by the larger area of the radial engine's front cowling), and the
model was ordered to be put in production as the Goshikisen (Go = five; shiki =
type; sentoki = fighter) or Army Fighter Type 5. The company's name was
Ki-100-1-Ko. All of the airframes were remanufactured from Ki-61-II Kai and
Ki-61-III airframes; the integral engine mount/cowling side panel was cut off
the fuselage and a tubular steel engine mount was bolted to the
firewall/bulkhead. Many of the redundant fittings from the liquid-cooled engine,
such as the ventral radiator shutter actuator, were still kept. The first 271
aircraft, or Ki-100-1-Ko, with the raised "razorback" rear fuselage were rolled
out of the factory between March and June 1945. A further 118 Ki-100 I-Otsu were
built with a cut-down rear fuselage and new rear-view canopy from May through to
the end of July 1945. This version also featured a modified oil cooler under the
engine in a more streamlined fairing.

The engine was reliable in contrast to the mechanical nightmares of the Nakajima
Ki-84, Kawasaki Ki-61, and Kawanishi N1K-J that kept many aircraft grounded.
Although slow in level flight for 1945, unlike most Japanese fighters, the
Ki-100 could dive with P-51 Mustangs and hold the speed on pullout. Two problems
which hampered the effective employment of Japanese fighters towards the end of
the war were unreliable electrical systems; that of the Ki-100 was less
problematic than most other aircraft types, although the fuse-boxes caused
problems; and poor radio communications, which was generic throughout the war.

The armament was two fuselage-mounted 20 mm Ho-5 cannons, each with 200 rpg.
These were complemented by two wing-mounted 12.7 mm (.50 in) Ho-103 machine guns
with 250 rpg.

Improvement of the basic model led to the Ki-100-II, with a turbocharged engine
for high-altitude interception of the B-29 Superfortresses, but only three
examples were built, and it never saw combat.


Role
Fighter

Manufacturer
Kawasaki Kokuki Kogyo K.K.

First flight
1 February 1945

Introduction
9 March 1945

Retired
August 1945

Primary user
Imperial Japanese Army Air Service

Produced
1945

Number built
396

Developed from
Kawasaki Ki-61

The Ki-100 made its combat debut on the night of 9 March 1945 and suffered its
first loss on 7 April 1945, when a Ki-100 flown by Master Sergeant Yasuo Hiema
of the 18th Sentai was shot down by a B-29 after "attacking the formation again
and again". Allied aircrews soon realised that they were facing a formidable new
fighter Although far fewer Ki-100s were available than the Ki-84s, it was
considered one of the most important fighters in the inventory. However, during
interception of the high-flying B-29s (the B-29 raids soon became low-level
missions) the new Japanese fighters struggled as the Ha-112-II engine's
performance decreased at high altitudes. The most effective way to attack the
Superfortress was by making very dangerous head-on attacks, with the fighter
hanging its approach path as it neared the bomber. A failure while attempting
this was deadly, because of the concentration of defensive fire from the
bombers. In this type of combat, the Navy's Mitsubishi J2M Raiden was superior.

An overall assessment of the effectiveness of the Ki-100 rated it highly in
agility, and a well-handled Ki-100 was able to outmanoeuvre any American
fighter, including the formidable P-51D Mustangs and the P-47N Thunderbolts
which were escorting the B-29 raids over Japan by that time, and was comparable
in speed, especially at medium altitudes. In the hands of an experienced pilot,
the Ki-100 was a deadly opponent; the Ki-100 and the Army's Ki-84 and the Navy's
Kawanishi N1K-J were the only Japanese fighters able to defeat the latest Allied
types.

Specifications (Ki-100-1a/b Goshikisen)

General characteristics
Crew: 1
Length: 8.82 m (28 ft 11 in)
Wingspan: 12.00 m (39 ft 4 in)
Height: 3.75 m (12 ft 4 in)
Wing area: 20 m² (215 ft²)
Empty weight: 2,525 kg (5,567 lb)
Loaded weight: 3,495 kg (7,705 lb)
Powerplant: 1 × Mitsubishi Ha 112-II radial engine, 1,120 kW (1,500 hp) at take
off

Performance
Maximum speed: 580 km/h (313 kn, 360 mph) at 6,000 m (19,700 ft)
Cruise speed: 400 km/h (217 kn, 249 mph)
Range: 2,200 km (1,189 nmi, 1,367 mi)
Service ceiling: 11,000 m (36,090 ft)
Climb to 5,000 m (16,400 ft): 6 min

Armament

Guns: 2 × 20 mm fuselage-mounted Ho-5 cannons, and 2 × 12.7 mm (.50 in)
wing-mounted Ho-103 machine guns





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