Mitsubishi Ki-46

https://en.wikipedia.org/wiki/Mitsubishi_Ki-46

The Mitsubishi Ki-46 was a twin-engine reconnaissance aircraft used by the
Imperial Japanese Army in World War II. Its Army Shiki designation was Type 100
Command Reconnaissance Aircraft (??????????); the Allied nickname was "Dinah".

On 12 December 1937, the Imperial Japanese Army Air Force issued a specification
to Mitsubishi for a long-range strategic reconnaissance aircraft to replace the
Mitsubishi Ki-15. The specification demanded an endurance of six hours and
sufficient speed to evade interception by any fighter in existence or
development, but otherwise did not constrain the design by a team led by Tomio
Kubo ???? (a 1931 graduate from the Aeronautical Section of the Faculty of
Engineering at Tokyo Imperial University) whose aesthetics are densely infused
to this elegant aircraft.

The resulting design was a twin-engined, low-winged monoplane with a retractable
tailwheel undercarriage. It had a small diameter oval fuselage which
accommodated a crew of two, with the pilot and observer situated in individual
cockpits separated by a large fuel tank. Further fuel tanks were situated in the
thin wings both inboard and outboard of the engines, giving a total fuel
capacity of 1,490 L (328 imperial gallons). The engines, two Mitsubishi Ha-26s,
were housed in close fitting cowlings developed by the Aeronautical Research
Institute of the Tokyo Imperial University to reduce drag and improve pilot
view.

Although at first the Ki-46 proved almost immune from interception, the Imperial
Japanese Army Air Force realised that improved Allied fighters such as the
Supermarine Spitfire and P-38 Lightning could challenge this superiority, and in
July 1942, it instructed Mitsubishi to produce a further improved version, the
Ki-46-III. This had more powerful, fuel-injected Mitsubishi Ha-112 engines, and
a redesigned nose, with a fuel tank ahead of the pilot and a new canopy,
smoothly faired from the extreme nose of the aircraft, eliminating the "step" of
the earlier versions. The single defensive machine gun of the earlier aircraft
was also omitted. The new version first flew in December 1942, demonstrating
significantly higher speed (630 km/h (391 mph) at 6,000 m (19,700 ft). The
performance of the Ki-46-III, proved superior to that of the aircraft intended
to replace it (the Tachikawa Ki-70), which as a result did not enter production.


Role
Twin-engine reconnaissance aircraft

Manufacturer
Mitsubishi

First flight
November 1939

Introduction
July 1941

Retired
September 1945

Primary user
Imperial Japanese Army Air Force

Number built
1,742

This aircraft was first used by the Japanese Army in Manchukuo and China, where
seven units were equipped with it, and also at times by the Japanese Imperial
Navy in certain reconnaissance missions over the northern coasts of Australia
and New Guinea.

The Japanese Army used this aircraft for the same type of missions (which were
not authorized) over present-day Malaysia during the months before the Pacific
War. Later, it was used for high altitude reconnaissance over Burma, Indochina,
Thailand, and the Indian Ocean. The Ki-46 was regarded by the British RAF in
Burma as a difficult aircraft to counter, only occasionally intercepting them
successfully. On September 25, 1944, Flying Officer Wittridge shot down a Ki-46,
using a personally modified Spitfire Mk. 8. Wittridge had removed two machine
guns and the seat armour, and also polished the wing leading edges to gain extra
speed. The leading American fighter pilot Richard Bong, flying a P-38 Lightning,
managed to shoot down a Ki-46 over the coast of Papua New Guinea in late 1942.

In 1944-45, during the last days of the war, it was modified as a high-altitude
interceptor, with two 20 mm cannon in the nose and one 37 mm (1.46 in) cannon in
an "upwards-and-forwards" position - almost like the Luftwaffe's Schräge Musik
night fighter cannon emplacements - for fighting USAAF B-29 Superfortresses over
the metropolitan Japanese islands. It lacked stability for sustained shooting of
the 37 mm (1.46 in) weapon, had only a thin layer of armour plating, lacked
self-sealing fuel tanks, and was slow to climb.

Specifications (Ki-46-II)

General characteristics
Crew: two (pilot and observer)
Length: 11.00 m (36 ft 1 in)
Wingspan: 14.70 m (48 ft 2¾ in)
Height: 3.88 m (12 ft 8¾ in)
Wing area: 32.0 m² (344 ft²)
Empty weight: 3,263 kg (7,194 lb)
Loaded weight: 5,050 kg (11,133 lb)
Max. takeoff weight: 5,800 kg (12,787 lb)

Performance
Maximum speed: 604 km/h (326 knots, 375 mph) at 5,800 m (19,000 ft)
Cruise speed: 400 km/h (217 knots, 249 mph)
Range: 2,474 km (1,337 nmi, 1,537 mi)
Service ceiling: 10,720 m (35,200 ft)
Wing loading: 157.8 kg/m² (32.3 lb/ft²)

Climb to 8,000 m (26,250 ft): 17 min 58 sec

Armament

Guns: 1× rearward-firing 7.7 mm (.303 in) Type 89 machine gun




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