Nakajima Ki.84 Hayate ("Frank")

Ki.84 (21 kb)

A Ki.84 from the 3rd Chutaī, 31rd Sentaī.

Role: single-seat fighter
Conception: T. Koyama
Production: More than 3,500 Hayate have been built by Nakajima Hikoki KK and Mansyu Hikoki Seizo KK
First flight of prototype: March or April, 1943

The Ki.84 Hayate (meaning: "Gale") is usually considered (along with the Ki.100) as one of the very best Japanese fighters of WW2; one of the very few to be a match for the North American P-51 Mustang on nearly every aspect.
However this high performance plane suffered from reliability problems, due to the poor quality of fuel and to the lack of time and formation for ground crews during the last two years of World War 2.
Colonel Frank McCoy, of the Allied Technical Air Intelligence Unit, nicknamed the new Japanese fighter after himself.

Development

The first pre-production Ki.84-Ia, or Army Type 4 Fighter Model 1a, was delivered in October of 1943. The first production aircraft left the factory in April of 1944.
The pilot of the Ki.84 was protected by an armored windshield and armor plate in the rear and floor of the cockpit.
During production, the engine power was increased from the 1,800 hp of the Ha-45 Model 11 up to the 1,990 hp of the Ha-45 Model 21.

Nakajima Ki.84-Ia Hayate "Frank"
Engine	Nakajima Ha-45 Model 12 18-cylinder radial	1,670 hp (WEP: 1,825 hp)
Weight	empty: 2,660 kg (5,864 lb) - maximum: 3,890 kg (8,576 lb)
Armament	Two cowl-mounted 12.7mm guns and two wing-mounted 20 mm cannons
Performance	Max speed: 630 km/h (392 mph)	Ceiling: 10,500 m (34,450 ft)

The Ki.84-Ib had an improved armament of two wing-mounted and two cowling-mounted 20 mm cannons.
The Ki.84-Ic was a dedicated bomber destroyer with two cowling-mounted 20 mm cannons, and two wing-mounted 30 mm cannons.
Late versions of the Ki.84-Ib and Ki.84-Ic were partially made of wood, in an attempt to reduce the need for aluminium. The codename stayed the same for the JAAF, but these versions were called Ki.84-II or Ki.84-KAI (KAI="modified") by Nakajima. Some of these were powered by the 2,000 hp Ha-45 Model 25.
The Ki.106, entirely made of wood, and the Ki.113, partially made of steel, were also attempts to save as much aluminium as possible. However performance suffered from the greater weight, and they didn't enter production.
As the Ha-45 engine was plagued with reliability problems, the Ki.116 prototype mixed a Ki.84 airframe with the 1,500 hp Mitsubishi Ha-112, already found in the Ki.46 Dinah recon plane and the Ki.100 fighter. This promising fighter was 450 kg (1,000 lb) lighter then the standard Ki.84, but the war ended before it could enter production.

Ki.84 (27 kb)

A Shotai (three-plane section) of Ki.84s of the 52th Sentai, at the end of 1944.

Stof's notes about this plane in iMOL's WarBirds

The opinions expressed below are only my own, and nothing more...

At last another Japanese Army fighter... and one of the best !
Now I'm looking forward to the Ki.44, Ki.45, and why not a Ki.100...

Strong points:

This plane climbs beautifully and has an excellent top speed.
The back view is quite uncluttered.

Weak points:

The Ki.84 is tougher than its predecessor the Ki.43, but it is not as solid as an American fighter.
Unexpectedly for a late war plane, it suffers from compressibility: the flight controls quickly become unresponsive in a high-speed dive.

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