Japanese Army Flag

Japan's Nakajima Ki-43 Hayabusa (peregrine falcon) fighter; Army Type 1
Allied code name: Oscar

Photos

Nakajima Ki-43 Hayabusa fighter:
Japan's Nakajima Ki-43 Hayabusa fighter 		Nakajima Ki-43 Hayabusa fighter:
Japan's Nakajima Ki-43 Hayabusa fighter		 Nakajima Ki-43 Hayabusa fighter:
Japan's Nakajima Ki-43 Hayabusa fighter		 Nakajima Ki-43-Ib Hayabusa fighter:
Japan's Nakajima Ki-43-Ib Hayabusa fighter
Two abandoned Nakajima Ki-43-II Hayabusa fighters:
Japan's Two abandoned Nakajima Ki-43-II Hayabusa fighters		      
Nakajima Ki-43 Hayabusa fighter (Japanese audio):
      

Design

The Imperial Japanese Army put forth specifications in 1937, that the Nakajima Ki-43 was selected, to replace the Nakajima Ki-27.1,4,5 The specifications were for a fighter that had a maximum speed of 310 mph, take five minutes to climb to 16,250', a range of 500 miles, two machine guns, and as maneuverable as the Ki-27.4 Nakajima entered a design by Hideo Itokawa and an order was placed in December 1937.1

Because of the rivalry with the Navy, the Army had to have its own fighter and picked the Nakajima Ki-43 over the Mitsubishi A6M.1 The Ki-43 became the Army's most produced fighter.3

Cockpit

The pilot of the Nakajima Ki-43 had some armor protection.1

Engine

The Ki-43 was intended to have the Ha-112 engine, but it wasn't put into production initially.1 It wasn't until the Ki-43-IIa that had the Ha-112 engine.1

The Nakajima Ki-43 Hayabusa's engine had to be manually started.1

Wings

Combat flaps, called "butterflies", were fitted in the wings to improve turning performance.1,4

Undercarriage

The undercarriage was retractable and some pilots didn't like it as they thought it was a heavy luxury.3,4

Prototype

The first prototype to fly was in January 1939.3,4 By March 1939 there were two more prototypes being tested.4

The Ki-43-II prototype first flew in February 1942.3

The Ki-43-IIIa prototype first flew in May 1944.3

Production

Deliveries of the Ki-43-IIa started in November 1942.3 The Ki-43-IIb entered production in November 1942.2

  • Prototypes: 33,4, 332,5
  • Service trial: 103,4
    • Production: November 1939 - September 1940.3,4
  • Nakajima Ki-43-I: 7163,4
    • Production: April 1941 - February 1943.3
  • Nakajima Ki-43-II prototype: 53
  • Nakajima Ki-43-II / Ki-43-III: 5,1903
    • Manufacturer: Nakajima (2,510)3, Tachikawa Hikoki (2,631)3, 1st Army Air Arsenal (49)3
  • Nakajima Ki-43-IIb:
    • Manufacturer: Nakajima2,5, Tachikawa2,5
    • Production: November 1942 - ? (Nakajima)5, May 1943 - ? (Tachikawa)5
  • Nakajima Ki-43-IIIa prototype: 23
  • Total: 5,8865, 5,9191,2,3,4
    • Manufacturer: Nakajima (3,239)1, Nakajima Hikoki K.K.4

Variants

  • Prototype: Used a Nakajima Ha-25 radial engine (925 HP).3
  • Service trial: Had fixed pitch wooden two bladed propeller.3 Later models had a two pitch propeller installed.3 To improve maneuverability combat flaps were installed.3
  • Nakajima Ki-43: Had 2: 7.7 mm machine guns in wings.1
  • Nakajima Ki-43-Ia: Had two 7.7 mm machine guns in upper cowling.3
  • Nakajima Ki-43-Ib: Had 1: 7.7 mm MG and 1: 12.7 mm MG in wings.1
  • Nakajima Ki-43-II prototype: Had a two speed super charged Ha-115 engine (1,150 HP).3 There was a constant speed three bladed propeller.3,4
  • Nakajima Ki-43-II-Ko: Mostly used as a fighter bomber.1
  • Nakajima Ki-43-IIa: The wing was "clipped".3 Windscreen and canopy were altered.3 13 mm armor protection for the pilot was added.3,4,5 Crude self sealing fuel tanks were installed.3,4 Hard points under wings.3
  • Nakajima Ki-43-IIb: Had 2: 12.7 mm machine guns in wings.1 Hard points in wings were repositioned.2
  • Nakajima Ki-43-II KAI:
  • Nakajima Ki-43-III: Had more powerful engine (1,230 HP).2,4,5 Speed was 358 / 576 kph.2,5
  • Nakajima Ki-43-IIIa:
  • Nakajima Ki-43-IIIb: It was to have cannons, but it never entered service.1 Developed by Tachikawa.3 Had Mitsubishi Ha-112 radial engine installed (1,300 HP).3,4

Usage

Japan and Thailand were the countries that used the Ki-43.3

The first 40 Ki-43-I-Hei were in service by December 1941.1

The Nakajima Ki-43 was used in Burma, China, the Philippine Islands, Thailand, and the Japanese home islands.1

It was equal to the Allied fighters early in the war but was soon outclassed by the newer Allied designs.1,2

First Campaigns

The Ki-43 was first used in the Malayan, Netherlands East Indies, and Burma campaigns.3

Thailand Use

The Royal Thai Air Force received twelve Ki-43s and these were used against American planes in southern China.3

Captured Tests

In September 1943 the Allies had captured several Oscars and were able to construct a complete one that they tested and were able to figure out how to counter it's exceptional maneuverability at low speed.1

Kamikaze

The Ki-43s were often used in kamikaze missions by 1945.1,3

Post World War II

Many Ki-43s survived to be used by the Indonesian forces against the Dutch.3 French pilots used some Ki-43s in Indo-China.3

Specifications

  Nakajima Ki-43-I Hayabusa3 Nakajima Ki-43-Ia Hayabusa3,4 Nakajima Ki-43-Ib Hayabusa3 Nakajima Ki-43-Ic Hayabusa3 Nakajima Ki-43-II Hayabusa3 Nakajima Ki-43 IIb Hayabusa1,2,4,5 Nakajima Ki-43 IIIa Hayabusa3
Type Fighter3 Fighter4     Fighter bomber3 Fighter1,2,4, Fighter bomber2,3,5 Fighter bomber3
Crew 13 14     13 11,2,4,5 13
Engine (Type) Nakajima Ha-253 Nakajima Ha-254     Nakajima Ha-1153,5 Nakajima Ha-115 piston1,2,4,5 Nakajima Ha-115-II3,4
Cylinders Radial 143 Radial 144     Radial5, Radial 143 Radial2,5, Radial 141,4 Radial4
Cooling   Air4       Air1,4  
Net HP 9803 9804     1,1503,5 1,1501,2,4,5 1,2303,4
Propeller blades 23       33 31,2 33
Dimensions              
Span 37' 6.5"3
11.44 m3 		37' 6"4     35' 6.75"3
10.84 m3 		35' 6"1,4, 35' 6.25"2, 35' 6.8"5
10.84 m1,2,5 		35' 6.75"3
10.84 m3
Length 28' 11.75"3
8.83 m3 		28' 11"4     29' 3.25"3
8.92 m3 		29' 3"1,4, 29' 3.2"5, 29' 3 1/8"2
8.92 m1,2,5 		29' 3.25"3
8.92 m3
Height 10' 8.75"3
3.27 m3 		10' 8"4     10' 8.75"3
3.27 m3 		10' 8"4, 10' 8.7"5, 10' 8.75"2, 10' 9"1
3.27 m1,2,5 		10' 8.75"3
3.27 m3
Wing area           230 ft2 1, 230.36 ft2 5, 230.37 ft2 2
21.4 m2 1,2,5 		 
Weight              
Empty   3,483 lb3
1,580 kg3 		      4,202 lb1, 4,211 lb2,3,5
1,910 kg1,2,3,5 		4,233 lb3
1,920 kg3
Loaded   4,515 lb3,4
2,048 kg3 		      5,710 lb4, 6,435 lb1, 6,449 lb5, 6,450 lb2,3
2,925 kg1,2,5, 2,926 kg3 		6,746 lb3
3,060 kg3
Maximum load   5,695 lb3
2,583 kg3 		         
Performance              
Speed         329 mph5
530 kph5 		329 mph1
530 kph1 		 
Speed @ 13,120' /
4,000 m 		308 mph3
495 kph3 		        329 mph3
529 kph3 		 
Speed @ 13,123' /
4,000 m 		          329 mph5
530 kph5 		 
Speed @ 13,125' /
4,000 m 		  308 mph4       329 mph2,4
530 kph2 		 
Speed @ 21,920' /
6,680 m 		            358 mph3
576 kph3
Cruising speed 199 mph3
320 kph3 		           
Climb to 16,400' /
5,000 m 		          5.8 minutes1  
Climb to 16,404' /
5,000 m 		          5.8 minutes5  
Climb to 16,405' /
5,000 m 		5.5 minutes3         5.8 minutes2,3 5.3 minutes3
Service ceiling 38,500'3
11,735 m3 		38,500'4       36,745'5, 36,750'1,2,3,4
11,200 m1,2,3,5 		37,400'3
11,400 m3
Range   745 miles4       1,090 miles1, 1,094 miles5, 1,095 miles2,3,4
1,760 km1,2,5, 1.762 km3 		1,320 miles3
2,124 km3
Range with external fuel tanks 808 miles3
1,300 km3 		           
Armament   2: MG4       2: MG4  
Nose   2: 7.7 mm MG3 1: 12.7 mm MG3
1: 7.7 mm MG3 		2: 12.7 mm MG3 2: 12.mm MG3 2: 12.7 mm MG1 2: 12.mm MG3
Wings           2: 12.7 mm Ho 103 MG2,5  
Bombs   66 lb4       551 lb4  
Bombs under wings         2: 551 lb3
2: 250 kg3 		2: 550 lb1, 2: 551 lb2,5
2: 250 kg1,2,5 		2: 551 lb3
2: 250 kg3

Sources:

  1. Aircraft of World War II, General Editor: Jim Winchester, 2004
  2. Fighting Aircraft of World War II, Editor: Karen Leverington, 1995
  3. Aircraft of WWII, Stewart Wilson, 1998
  4. World War II Airplanes Volume 2, Enzo Angelucci, Paolo Matricardi, 1976
  5. The Encyclopedia of Weapons of World War II, Chris Bishop, 1998