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Japan's Nakajima Ki-43 Hayabusa (peregrine falcon) fighter1,2,3
Allied Name: "Oscar"1,2,3
Nakajima Ki-43, "Oscar" fighter:
Nakajima Ki-43, "Oscar" fighter:
Nakajima Ki-43-Ib, "Oscar" fighter:
Design
The Imperial Japanese Army put forth specifications, that the Nakajima Ki-43 was selected, to replace the Nakajima Ki-27 (allied code name Nate).1 Nakajima entered the Ki-45 design 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 were fitted in the wings to improve turning performance.1
Undercarriage
The undercarriage was retractable and some pilots didn't like it as they thought it was a heavy luxury.3
Prototype
The first prototype to fly was in January 1939.3
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, 332
- Service trial: 103
- Built between November 1939 and September 1940.3
- Ki-43-I: 7163
- Produced from April 1941 to February 1943.3
- Ki-43-II prototype: 53
- Ki-43-II / Ki-43-III: 5,1903
- Produced by: Nakajima (2,510)3, Tachikawa Hikoki (2,631)3, 1st Army Air Arsenal (49)3
- Ki-43-IIb:
- Produced by: Nakajima2, Tachikawa.2
- Ki-43-IIIa prototype: 23
- Total: 5,9191,2,3
- Nakajima: 3,2391
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
- Ki-43: Had 2: 7.7 mm MGs in wings.1
- Ki-43-Ia: Had two 7.7 mm MGs in upper cowling.3
- Ki-43-Ib: Had 1: 7.7 mm MG and 1: 12.7 mm MG in wings.1
- 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
- Ki-43-II-Ko: Mostly used as a fighter bomber.1
- Ki-43-IIa: The wing was "clipped".3 Windscreen and canopy were altered.3 Minor armor protection for the pilot was added.3 Crude self sealing fuel tanks were installed.3 Hard points under wings.3
- Ki-43-IIb: Had 2: 12.7 mm MGs in wings.1 Hard points in wings were repositioned.2
- Ki-43-II KAI:
- Ki-43-III: Had more powerful engine (1,230 HP).2 Speed was 358 / 576 kph.2
- Ki-43-IIIa:
- 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
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
| Nakajima Ki-43-I Hayabusa3 | Nakajima Ki-43-Ia Hayabusa3 | Nakajima Ki-43-Ib Hayabusa3 | Nakajima Ki-43-Ic Hayabusa3 | Nakajima Ki-43-II Hayabusa3 | Nakajima Ki-43 IIb Hayabusa 1,2 | Nakajima Ki-43 IIIa Hayabusa3 | |
|---|---|---|---|---|---|---|---|
| Type | Fighter3 | Fighter bomber3 | Army fighter1,2 Fighter bomber2,3 |
Fighter bomber3 | |||
| Crew | 13 | 13 | 11,2 | 13 | |||
| Engine (Type) | Nakajima Ha-253 | Nakajima Ha-1153 | Nakajima Ha-115 piston1,2 | Nakajima Ha-115-II3 | |||
| Cylinders | Radial 143 | Radial 143 | Radial1,2 141 | ||||
| Cooling | Air1 | ||||||
| Net HP | 9803 | 1,1503 | 1,1501,2 | 1,2303 | |||
| Propeller blades | 23 | 33 | 31,2 | 33 | |||
| Dimensions | |||||||
| Span | 37' 6.5"3 11.44 m3 |
35' 6.75"3 10.84 m3 |
35' 6"1, 35' 6.25"2 10.84 m1,2 |
35' 6.75"3 10.84 m3 |
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| Length | 28' 11.75"3 8.83 m3 |
29' 3.25"3 8.92 m3 |
29' 3"1, 29' 3 1/8"2 8.92 m1,2 |
29' 3.25"3 8.92 m3 |
|||
| Height | 10' 8.75"3 3.27 m3 |
10' 8.75"3 3.27 m3 |
10' 8.75"2, 10' 9"1 3.27 m1,2 |
10' 8.75"3 3.27 m3 |
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| Wing area | 230 ft2 1, 230.37 ft2 2 21.4 m2 1,2 |
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| Weight | |||||||
| Empty | 3,483 lb3 1,580 kg3 |
4,202 lb1, 4,211 lb2,3 1,910 kg1,2,3 |
4,233 lb3 1,920 kg3 |
||||
| Loaded | 4,515 lb3 2,048 kg3 |
6,435 lb1, 6,450 lb2,3 2,925 kg1,2, 2,926 kg3 |
6,746 lb3 3,060 kg3 |
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| Maximum load | 5,695 lb3 2,583 kg3 |
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| Performance | |||||||
| Speed | 329 mph1 530 kph1 |
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| Speed @ 13,120' / 4,000 m |
308 mph3 495 kph3 |
329 mph3 529 kph3 |
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| Speed @ 13,125' / 4,000 m |
329 mph2 530 kph2 |
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| Speed @ 21,920' / 6,680 m |
358 mph3 576 kph3 |
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| Cruising speed | 199 mph3 320 kph3 |
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| Climb to 16,400' / 5,000 m |
5.8 minutes1 | ||||||
| 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 |
36,750'1,2,3 11,200 m1,2,3 |
37,400'3 11,400 m3 |
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| Range | 1,090 miles1, 1,095 miles2,3 1,760 km1,2, 1.762 km3 |
1,320 miles3 2,124 km3 |
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| Range with external fuel tanks | 808 miles3 1,300 km3 |
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| Armament | |||||||
| 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 | ||||||
| Bombs under wings | 2: 551 lb3 2: 250 kg3 |
2: 550 lb1, 2: 551 lb2 2: 250 kg1,2 |
2: 551 lb3 2: 250 kg3 |
Sources:
- Aircraft of World War II, General Editor: Jim Winchester, 2004
- Fighting Aircraft of World War II, Editor: Karen Leverington, 1995
- Aircraft of WWII, Stewart Wilson, 1998
