The Mitsubishi A5M, Navy designation Mitsubishi Navy Type 96 Carrier-based Fighter, experimental Navy designation Mitsubishi Navy Experimental 9-Shi Carrier Fighter, company designation Mitsubishi Ka-14, was a Japanese carrier-based fighter aircraft.
It was the world’s first low-wing monoplane shipboard fighter to enter service
In 1934, the Imperial Japanese Navy prepared a specification for an advanced fighter, requiring a maximum speed of 350 km/h (220 mph) at 3,000 m (9,800 ft) and able to climb to 5,000 m (16,000 ft) in 6.5 minutes.
This 9-shi (1934) specification produced designs from both Mitsubishi and Nakajima.
Mitsubishi assigned the task of designing the new fighter to a team led by Jiro Horikoshi (original creator of the similar but unsuccessful Mitsubishi 1MF10, and later responsible for the famous A6M Zero).
The resulting design, designated Ka-14 by Mitsubishi, was an all-metal low-wing fighter, with a thin elliptical inverted gull wing and a fixed undercarriage, which was chosen as the increase in performance (estimated as 10% in drag, but only a mere 3% increase in maximum speed) arising from use of a retractable undercarriage was not felt to justify the extra weight.
The first prototype, powered by a 447 kW (600 hp) Nakajima Kotobuki 5 radial engine, flew on 4 February 1935.
The aircraft far exceeded the requirements of the specification, with a maximum speed of 450 km/h (280 mph) being reached.
The second prototype was fitted with a revised, ungulled wing, and after various changes to maximize manoeuvrability and reduce drag, was ordered into production as the A5M.
With the Ka-14 demonstrating excellent performance, the Imperial Japanese Army Air Force ordered a single modified prototype for evaluation as the Ki-18.
While this demonstrated similar performance to the Navy aircraft and hence was far faster than the IJAAF’s current fighter, the Kawasaki Ki-10 biplane, the type was rejected by the army owing to its reduced manoeuvrability.
The Army then produced a specification for an improved advanced fighter to replace the Ki-10.
Mitsubishi, busy turning the Ka-14 into the A5M, submitted a minimally changed aircraft as the Ki-33, this being defeated by Nakajima’s competing aircraft, which was ordered into service as the Ki-27.
Variants
Ka-14
Six prototypes with various engines and design modifications.
A5M1
Navy carrier-based fighter, Model 1
First production model with 633 kW (850 hp) Kotobuki 2 KAI I engine.
A5M2/2a/Model 21
More powerful engine.
A5M2b/Model 22
First production examples with NACA cowling and 477 kW (640 hp) Kotobuki 3 engine.
A5M3a
Prototypes with 448 kW (601 hp) Hispano-Suiza 12 Xcrs engine.
A5M4
Model 24 (ex-Model 4): The A5M2b with different engine, closed cockpit, additional detachable fuel tank. The last production models (Model 34) with Kotobuki 41 KAI engine.
A5M1-A5M4
780 constructed by Mitsubishi. 39 constructed by Watanabe, 161 manufactured by Naval Ohmura Arsenal.
A5M4-K
Two-seat trainer version of A5M4, 103 constructed by Naval Ohmura Arsenal.
Mitsubishi Ki-18
Single prototype land-based version for IJAAF, based on the A5M. 410 kW (550 hp) Kotobuki 5 engine.
Mitsubishi Ki-33
Two prototypes, a development of Ki-18 with a different engine, and closed cockpit.
Total Production (all variants): 1,094
Specifications
Crew
1
Length
7.565 m (24 ft 10 in)
Wingspan
11 m (36 ft 1 in)
Height
3.27 m (10 ft 9 in)
Wing area
17.8 m2 (192 sq ft)
Airfoil
Root
B-9 mod. (16%)
Tip
B-9 mod (9%)
Empty weight
1,216 kg (2,681 lb)
Gross weight
1,671 kg (3,684 lb)
Powerplant
1 × Nakajima Kotobuki 41 or 41 KAI,
9-cylinder air-cooled radial piston engine,
530 kW (710 hp) for take-off
585 kW (785 hp) at 3,000 m (9,843 ft)
Propellers
3-bladed metal propeller
Performance
Maximum speed
435 km/h (270 mph, 235 kn) at 3,000 m (9,843 ft)
Range
1,201 km (746 mi, 648 nmi)
Service ceiling
9,800 m (32,200 ft)
Time to altitude
3,000 m (9,843 ft) in 3 minutes 35 seconds
Wing loading
93.8 kg/m2 (19.2 lb/sq ft)
Power/mass
0.3161 kW/kg (0.1923 hp/lb)
Armament
Guns
2× 7.7 mm (0.303 in) Type 97 aircraft machine gun fuselage-mounted synchronized machine guns firing through the engine cylinders and propeller at about 1 and 11 o’clock.
