Kawanishi K-3
The Kawanishi K-3 was a Japanese, fast, multi-purpose civil transport aircraft from the early 1920s. Despite its good performance it was eclipsed by the release of Army surplus machines and only one was built.
| Kawanishi K-3 | |
|---|---|
| Role | Civil passenger and general purpose transport aircraft |
| National origin | Japan |
| Manufacturer | Kawanishi Aircraft |
| Designer | Eiji Sekiguchi |
| First flight | 1921 |
| Number built | 1 |
| Developed from | Kawanishi K-1 |
Design and development
The K-3, completed in October 1921, was designed as a fast civil transport able to carry two passengers or mail and other cargo. It was a development of the Kawanishi K-1 completed in December 1920 and was more powerful, aerodynamically cleaner and faster. Like most aircraft of its period it had a wooden structure and was fabric-covered.[1]
It was a single bay biplane with rectangular plan wings braced by parallel pairs of interplane struts. The upper wing was joined to the upper fuselage by a cabane formed by pairs of transverse outward-leaning inverted V-struts to the forward wing spar and similar but longitudinal V's to the rear. The lower wing was joined as usual to the lower fuselage longerons.[1]
At the end of World War I Japan received a large number of Maybach engines, designed to power airships, as part of its war reparations. The K-3 was the first Japanese aircraft to use one, a Maybach Mb.IVa six cylinder, water-cooled, upright straight engine producing 260–305 hp (194–227 kW). Its radiator was mounted horizontally in the upper wing centre section to reduce drag. It was nose-mounted and smoothly faired into the fuselage behind. An open, underwing cockpit seated two passengers side-by-side, with the pilot in a second open cockpit well behind the wing trailing edges.[1]
The K-3 had a fixed, conventional undercarriage with mainwheels on a single axle with pairs of faired landing legs and rearward drag struts mounted on the lower fuselage longerons. There was a short tailskid.[1]
Operational history
The K-3 first flew in the early winter of 1921. It was the fastest civil aircraft in Japan, with the speed of a fighter and the load-carrying ability of a light bomber. Kawanishi had hopes of commercial success but instead the light civil transport market was filled by the lower-powered and slower Nakajima Type 5 Trainers released by the Army and no more K-3s were built.[1]
In 1926 the sole K-3 was modified to take a straight six, 200–230 hp (150–170 kW) Benz Bz.IIIaV (Benz Bz.IV)[2][Notes 1] engine as well as other changes to become the Kawanishi K-3B.
Variants
- Kawanishi K-3
- Prototype with 260–305 hp (194–227 kW) Maybach Mb.IVa.
- Kawanishi K-3B
- Prototype with 200–230 hp (150–170 kW) Benz Bz.IV and airframe modifications.
Specifications (K-3)
Data from Japanese Aircraft 1910-1941[1]
General characteristics
- Crew: one
- Capacity: two passengers
- Length: 8.86 m (29 ft 1 in)
- Wingspan: 10.03 m (32 ft 11 in)
- Height: 2.60 m (8 ft 6 in)
- Wing area: 30.5 m2 (328 sq ft)
- Airfoil: RAF 15
- Empty weight: 970 kg (2,138 lb)
- Gross weight: 1,400 kg (3,086 lb)
- Powerplant: 1 × Maybach Mb.IVa six cylinder water-cooled inline, 194–227 kW (260–305 hp)
- Propellers: wooden
Performance
- Maximum speed: 230 km/h (140 mph, 120 kn)
- Landing Speed: 97 km/h (60 mph; 52 kn)
- Endurance: 5 hr
- Service ceiling: 8,500 m (27,900 ft)
- Time to altitude: 10 min to 3,000 m (9,800 ft)
Notes
- The Bz.IIIaV form given by Mikesh and Abe is unusual. The power range matches that of an engine named by Gunston as the Benz Bz.IV, so this has been linked.