NAKAJIMA Ki 43 HAYABUSA (PAREGRINE FALCON) 'OSCAR'
12 December 1938: Ki 43 prototype 1st flight.
Ki 43: Pre-production aircraft: Engine: Ha-25 990 hp./T.O./2,700 rpm. 970 hp./11,155 ft. (3,400.9 m.)/2,600 rpm.
Ki 43-Otsu: The 8th pre-production aircraft received the 'butterfly' combat flaps (Fowler-type).
June 1941: Deliveries of the Ki 43-la-Ko begin to the 59th & 64th Sentai.
Engine: Nakajima Ha-25 with a single speed supercharger.
Propeller: Fixed-pitch, two-blade wooden propeller soon gave way to a variable-pitch metal propeller.
Armament: 2 x 7.7 mm. type 89/500 rpg.
Wing span: 37 ft. 6.3 in.
Wing area: 236.805 sq. ft.
Combat Weight: 4,515 lbs.
Power Loading: 4.561-lbs./hp.
Wing Loading: 19.07-lbs/sq. ft. NOTE: This is close to biplane territory.
June 1941: Deliveries of the Ki 43-lb-Otso begin to the 59th & 64 Sentai.
Armament: 1 x 7.7 mm. type 89/500 rds. + 1 x 12.7 mm. Ho-103/250 rds.
8 December 1941: 1st combat of the Ki 43. 40 Ki 43s are now operational.
Ki 43-lc-Hei: Of the first 716 Ki 43s built all but the first 80 were built to Ki 43-lc standards.
Standard armament became 2 x 12.7 mm. Ho-103 machine guns/250 rpg.
February 1942: five Ki 43-ll prototypes were delivered to the IJAAF.
October 1942: Ki 43-lla-Ko was in full production.
November 1942: The 1st production Ki 43-lla-Ko aircraft was completed.
Engine: Nakajima Ha-115: 1,150 hp./T.O./2,800 rpm. 1,100 hp./9,350 ft. (2,850.6 m.)/2,800 rpm.
980 hp./19,685 ft. (6,000 m.)/2,700 rpm. Two-speed supercharger and 3 blade metal propeller.
Air intake for the supercharger is installed at the upper lip of the cowling.
13 mm. head and back armor are added.
Layers of rubber now coat the fuel tanks.
Slightly taller windscreen and canopy.
A more effective reflector gun sight is installed.
An oil cooler was fitted under the fuselage at the rear of the cowling.
Armament: 2 x 12.7 mm./250 rpg.
Further wing modifications cured its tendency to collapse under high loadings.
Wingspan is shortened by 23.6 in. and load carrying capacity of racks is increased.
Speed (military): 329 mph./4,000 m.
Service Ceiling: 36,750 ft.
Range: 1,095 mls.
January 1943: Deliveries of the Ki.43-IIa-Ko began to the IJAAF.
February 1943: The last Ki.43-I rolled out of the Ota plant.
June 1943: Deliveries of the Ki 43-IIb-Otso.
Various minor modifications incorporated during the production run became standardized in this model.
Deeper "honeycomb" oil cooler under the cowling, a revised air intake for the carburetor & and
auxiliary cooler intake beneath the fuselage were installed.
Later in the production run the wing hard points were moved further out on the wing to prevent bombs
from striking the propeller.
Combat Weight: 5,710 lbs.
Wing Area: 230.367 sq. ft.
Power Loading: 4.965+lbs./hp.
Wing Loading: 24.79-lbs./sq. ft.
June 1943: Deliveries of the Ki 43-llc (Ki 43-ll-KAI) began.
Injector exhaust stubs were installed giving the engine a slight boost in horsepower.
May 1944: Work began on 10 Ki 43-lll-Ko prototypes. Tachikawa built 1,098 Ki 43-llla & two Ki 43-lllb
Engine: Nakajima Ha-115-ll: 1,190 hp./T.O./2,800 rpm. 1,230 hp./9,185 ft. (2,800 m.)/2,700 rpm.
Combat Weight: Ki.43-IIIa: 5,644 lbs.
Wing Area: 230.367 sq. ft.
Power Loading: 4.589-lbs./hp.
Wing Loading: 24.50+lbs./sq. ft.
Ki 43-lllb with 2 x 20 mm. cannon and a Mitsubishi Ha-112-32/42 engine: 1,300 hp.
The war ended just before this model entered production.
Air International January 1980 Vol.18 No.1
Page 26: "...the Hayabusa also emulated the Ki27 in that its true combat element was close-in high-g
maneuvering; its controls were highly sensitive and it possessed no vicious characteristics - it could
be flown "by the seat of the pants"." "...it lacked the firepower and fuel tank & pilot protection. ...its
structure, while not fragile, was incapable of absorbing the punishment that could be meted out by
more heavily armed opponents, and it could be out-dived and out-zoomed by most Allied fighter."
Page 28: With the installation of the "butterfly" combat flaps (Fowler-type) on the 8th pre-production
aircraft: "...the Ki 43 was able to hold its own in most respects with the supremely maneuverable
Ki 27..." " It was found that the fighter could be looped and Immelmanned at airspeeds of 168 mph.
and lower, acceleration from low airspeeds was exceptional, stall recovery was impeccable - in a
hammerhead stall with an airspeed as low as 31 mph. indicated it gently rolled on its back and then
fell through nicely - and the "butterfly" flaps endowed the Ki 43 with an astonishing rate of turn."
"The Ki 43 was , in some ways, more dangerous to deal with than the A6M, chiefly because it had
a better rate of roll and was armed with two 12.7 mm. machine guns."
"The Ki 43 had better wing loading and power loading than the Zero, had superior initial acceleration
a better roll rate and a tighter turning circle."
The Ki.43 mounted a high-pressure oxygen cylinder behind the pilot's seat that had a nasty habit
of exploding if struck by enemy fire.
God bless all, Jeff
Edited by CORSNING, 26 February 2017 - 04:46 PM.