Kawanishi N1K

https://en.wikipedia.org/wiki/Kawanishi_N1K

The Kawanishi N1K Kyofu ("Strong Wind", Allied reporting name "Rex") is an
Imperial Japanese Navy floatplane fighter. The Kawanishi N1K-J Shiden ("Violet
Lightning") was an Imperial Japanese Navy Air Service land-based version of the
N1K. Assigned the reporting name "George", the N1K-J was considered by both its
pilots and opponents to be one of the finest land-based fighters flown by the
Japanese during World War II.

The Shiden Kai possessed heavy armament as well as surprisingly good
maneuverability, due to a mercury switch that automatically extended the flaps
during turns. These "combat" flaps created more lift, thereby allowing tighter
turns. Unlike the Mitsubishi A6M Zero, the Shiden Kai could compete against the
best late-war Allied fighters, such as the F6F Hellcat, F4U Corsair, and P-51
Mustang.

Design and development

Kawanishi's N1K was originally built as a single pontoon floatplane fighter to
support forward offensive operations where no airstrips were available, but by
1943 when the aircraft entered service, Japan was firmly on the defensive and
there was no longer a need for a fighter to fulfill this role. It was powered by
the Mitsubishi MK4C Kasei 13 14-cylinder radial engine.

The requirement to carry a bulky, heavy float essentially crippled the N1K
against contemporary American fighters. However, Kawanishi engineers had
proposed in late 1941 that the N1K would also be the basis of a formidable
land-based fighter and a land-based version was produced as a private venture by
the company. This version flew on 27 December 1942 powered by a Nakajima NK9A
Homare 11 18-cylinder radial engine, replacing the less powerful MK4C Kasei 13
of the N1K-1. The aircraft retained the mid-mounted wing of the floatplane and
combined with the large propeller this necessitated a long, stalky main landing
gear. A unique feature was the aircraft's combat flaps that automatically
adjusted in response to acceleration, freeing up the pilot's concentration and
reducing the chance of stalling in combat. The N1K did have temperamental flight
characteristics, however, that required an experienced touch at the controls.

The Nakajima Homare was powerful but had been rushed into production before it
was sufficiently developed and proved troublesome. Another problem was landing
gear failure due to poor heat treatment of the wheels. Apart from engine
problems and the landing gear, the flight test program showed that the aircraft
was promising. Prototypes were evaluated by the Navy, and since the aircraft was
faster than the Zero and had a much longer range than the Mitsubishi J2M Raiden,
it was ordered into production as the N1K1-J, the -J indicating a land-based
fighter modification of the original floatplane fighter.

Only four days after the Shiden's first test flight a complete redesign was
begun. The N1K2-J addressed the N1K1-J's major defects, primarily the
mid-mounted wing and long landing gear. The wings were moved to a low position,
which permitted the use of shorter, conventional undercarriage. The fuselage was
lengthened and the tail redesigned. The production of the entire aircraft was
simplified: over a third of the parts used in the previous Shiden could still be
used in its successor while construction used fewer critical materials. The N1K1
redesign was approximately 250 kg (550 lb) lighter and was faster and more
reliable than its predecessor. The Homare engine was retained even though
reliability problems persisted as no alternative was available. A prototype of
the new version flew on 1 January 1944. After completing Navy trials in April
the N1K2-J was rushed into production. This variant was named the "Shiden-Kai",
with Kai meaning modified.

Role
Fighter

National origin
Japan

Manufacturer
Kawanishi Aircraft Company

First flight
N1K1: 6 May 1942
N1K1-J: 27 December 1942
N1K2-J: 31 December 1943

Introduction
1943

Retired
1945

Primary user
Imperial Japanese Navy Air Service

Number built
1,532

Operational history

The N1K1-J Shiden entered service in early 1944. The N1K1-J, and the N1K2
Shiden-Kai released later that year, were among the rare Japanese aircraft that
offered pilots an even chance against late-war American designs such as the F6F
Hellcat and the F4U Corsair, and either could be a formidable weapon in the
hands of an ace. In February 1945 Lieutenant Kaneyoshi Muto, flying a N1K2-J as
part of a formation of at least 10 expert Japanese pilots, faced seven US Navy
Hellcat pilots, from squadron VF-82, in the sky over Japan. The formation shot
down four Hellcats with no loss to themselves. After the action, Japanese
propagandists fabricated a story in which Muto was the sole airman facing 12
enemy aircraft. (The leading Japanese ace Saburo Sakai, later mentioned, in an
autobiography, that Muto had, at an earlier stage of the war – albeit at the
controls of a Zero fighter.)

The N1K1-J aircraft were used very effectively over Formosa (Taiwan), the
Philippines, and, later, Okinawa. Before production was switched to the improved
N1K2-J, 1,007 aircraft were produced, including prototypes. Production
difficulties and damage resulting from B-29 raids on factories led to only 415
of the superior N1K2-J fighters being produced.

The N1K2-J Shiden-Kai proved to be one of the best dogfighting aircraft produced
by either side. Along with high speed the Shiden-Kai offered pilots an agile
aircraft with a roll rate of 82°/sec at 386 km/h (240 mph) backing four powerful
20 mm cannons in the wings. As a bomber interceptor the N1K2-J fared less well,
hampered as it was by a poor rate of climb and reduced engine performance at
high altitude.

Specifications (N1K1-J)

General characteristics
Crew: 1
Length: 8.885 m (29 ft 2 in)
Wingspan: 12 m (39 ft 4 in)
Height: 4.06 m (13 ft 4 in)
Wing area: 23.5 m2 (253 sq ft)
Airfoil: LB620515-6075
Empty weight: 2,897 kg (6,387 lb)
Gross weight: 3,900 kg (8,598 lb)
Max takeoff weight: 4,321 kg (9,526 lb)
Fuel capacity: 477 l (126 US gal; 105 imp gal) internal + 323 l (85 US gal; 71
imp gal) drop tank ; maximum 800 l (210 US gal; 180 imp gal)
Powerplant: 1 × Nakajima NK9H Homare 21 18-cylinder air-cooled radial piston
engine, 1,473 kW (1,975 hp) at sea level
1,223 kW (1,640 hp) at 2,164 m (7,100 ft) Normal
1,398 kW (1,875 hp) at 1,798 m (5,900 ft) Military with methanol/water injection
1,249 kW (1,675 hp) at 5,980 m (19,620 ft) Military with methanol/water
injection
1,529 kW (2,050 hp) at 762 m (2,500 ft) War Emergency with methanol/water
injection
Propellers: 4-bladed, 2.987 m (9 ft 9.6 in) diameter constant-speed propeller

Performance
Maximum speed: 571 km/h (355 mph, 308 kn) at 3,500 kg (7,717 lb) at sea level
656 km/h (408 mph; 354 kn) at 6,096 m (20,000 ft)
Range: 1,078 km (670 mi, 582 nmi) at 272 km/h (169 mph; 147 kn) at 457 m (1,500
ft)
813 km (505 mi; 439 nmi) at 75% Vmaxat 391 km/h (243 mph; 211 kn) at 457 m
(1,500 ft)
Ferry range: 1,746 km (1,085 mi, 943 nmi) maximum with drop tank at 269 km/h
(167 mph; 145 kn) at 457 m (1,500 ft)
1,078 km (670 mi; 582 nmi) at 75% Vmax at 381.5 km/h (237.1 mph; 206.0 kn) at
457 m (1,500 ft)
Service ceiling: 12,009 m (39,400 ft)
Rate of climb: 19.7 m/s (3,880 ft/min) at 3,500 kg (7,717 lb) at sea level
4,065 ft/min at 3,500 kg (7,717 lb) at 1,798 m (5,900 ft)
Time to altitude: 3,048 m (10,000 ft) in 2 minutes 36 seconds
6,096 m (20,000 ft) in 5 minutes 36 seconds
Wing loading: 166 kg/m2 (34 lb/sq ft)
Power/mass: 0.38 kW/kg (0.23 hp/lb)

Armament

Guns:

4× 20 mm Type 99 Mark 2 machine guns in the wings.
Bombs:

2× 250 kg (551 lb) bombs
or1× 323 l (85 US gal; 71 imp gal) drop tank




*