Nakajima Ki-44

https://en.wikipedia.org/wiki/Nakajima_Ki-44

The Nakajima Ki-44 Shoki (??, Zhong Kui) was a single-engine fighter aircraft
used by the Imperial Japanese Army Air Force in World War II. The type first
flew in August 1940 and entered service in 1942. The Allied reporting name was
"Tojo"; the Japanese Army designation was "Army Type 2 Single-Seat Fighter".

It was less maneuverable than its predecessor, the nimble Ki-43, and pilots
disliked its poor visibility on the ground, its higher landing speed, and severe
restrictions on maneuvering. Yet, it was obvious the Ki-44 was clearly superior
overall as a combat aircraft compared to the Ki-43. As an interceptor it could
match Allied types in climbs and dives, giving pilots more flexibility in combat
and greater pilot confidence than the Ki-43. Moreover, the basic armament of
four 12.7mm machine guns or two 12.7mm guns and two 20 mm cannons (plus a few
aircraft which carried two Ho-301 40 mm cannons of limited performance) was far
superior to the older Ki-43's two 12.7mm machine guns. These characteristics
made the fighter, despite performance restrictions at altitude, a useful B-29
Superfortress interceptor and one of the Japanese High Command priorities during
the last year of war. However, like most of the Japanese aircraft flown in the
last part of the war, the low availability of properly trained pilots made them
easy targets for experienced, aggressive, and well trained Allied pilots flying
superior aircraft.

Nakajima began development of the Ki-44 in 1940 as a pure interceptor with
emphasis being placed on airspeed and rate of climb rather than maneuverability.
The Japanese Army Air Force specification called for a maximum speed of 600 km/h
(370 mph) at 4,000 m (13,130 ft), to be attained in five minutes. A set of
Ki-43-like "butterfly" combat flaps was fitted for improved maneuverability.
Armament consisted of a pair of 7.7 mm (.303 in) and a pair of 12.7 mm (.50 in)
machine guns.

The engine selected for the new interceptor was Nakajima's Ha-41 (a development
of the Nakajima Ha-5) 14-cylinder double-row radial, originally intended for
bomber aircraft. Although the Ha-41 was not the ideal choice due to its
large-diameter cross section, the design team was able to marry this engine to a
much smaller fuselage with a narrow cross section. At 1,260 mm in diameter, the
Ha-41 was 126 mm larger in diameter than the 1,144 mm Nakajima Sakae (used in
the Mitsubishi A6M "Zero" and Nakajima Ki-43 "Hayabusa"). However, the Sakae was
only 27.8L in displacement and 1,000 hp, while the Ha-41 was 37.5L and made
1,260 hp (1,440 in the later Ha-109 version). In any case, since the Sakae
wasn't powerful enough, the only alternative available was the Mitsubishi
Kinsei, which was slightly smaller than the Ha-41 in diameter, five liters
smaller in displacement, and was less powerful. Unfortunately, this was already
in demand for many other aircraft, so the Ha-41 was chosen as the best
powerplant. In order to achieve its design goals, the wing area was relatively
small leading to a high wing loading and a comparatively high landing speed that
could be daunting to the average Japanese pilot, who was more used to aircraft
with a low wing loading like the Ki-44s predecessors, the Ki-43 and Ki-27.


Role
Fighter aircraft

Manufacturer
Nakajima Aircraft Company

Designer
Yasushi Koyama

First flight
August 1940

Introduction
1942

Retired
1945

Primary user
Imperial Japanese Army Air Force

Produced
1940–1944

Number built
1,225

The Ki-44-II Otsu (also known as the Ki-44-IIb) could be armed with a Ho-301 40
mm autocannon. While this was a relatively high-caliber weapon, it used caseless
ammunition with a low muzzle velocity and short range, which was effective only
in close attacks. Some of these aircraft were used against USAAF bombers by a
special Shinten Seiku Tai (air superiority unit), comprising at least four
aircraft, that was part of 47 Sentai, based at Narimasu airfield in Tokyo.
Pilots from such units attempted to shoot down B-29s and, once their ammunition
was expended, to ram them – effectively a suicide attack. While the concept
appeared straightforward, ramming a B-29 at high altitudes was difficult to
achieve in practice.

By the end of the war, Ki-44 variants were being replaced by the Nakajima Ki-84
Hayate, which was regarded as vastly superior – in aspects other than
maintenance and reliability

Specifications (Ki-44-II Otsu)

General characteristics
Crew: one, pilot
Length: 8.84 m (29 ft)
Wingspan: 9.45 m (31 ft 01 in)
Height: 3.12 m (10 ft 23 in)
Wing area: 15 m² (161 ft²)
Empty weight: 2,106 kg (4,643 lb)
Loaded weight: 2,764 kg (6,094 lb)
Max. takeoff weight: 2,998 kg (6,609 lb)
Powerplant: 1 × Nakajima Ha-109 Army Type 2 fourteen cylinder air-cooled radial
engine, 1,133 kW (1,519 hp)

Performance
Maximum speed: 605 km/h at 5,200 m (376 mph at 17,060 ft)
Cruise speed: 400 km/h at 4,000 m (249 mph at 13123 ft)
Stall speed: 150 km/h (93 mph)
Service ceiling: 11,200 m (36,750 ft)
Rate of climb: 5,000 m--4 min 17 sec (3,940 ft/min)
Wing loading: 200 kg/m² (41 lb/ft²)
Power/mass: 0.38 kW/kg (0.13 hp/lb)

Armament

2× 12.7 mm (.50 in) Ho-103 machine guns synchronized cowl mounted (perhaps 657
rpm rate each). The 12.7x81 cartridge propelled the 35.4 g AP bullet 760 m/s,
the 38 g HE 796 m/s, and the 33 g HE (2.2%) 770 m/s, with an effective firing
range of 750 m. Not always reliable. Optional provision for two 40 mm (1.57 in)
Ho-301 cannons in the wings, firing caseless ammunition.





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