Kawasaki C-5

In June 1933 the Japanese newspaper Asahi Shimbun ordered a fast, long range communications aircraft from the Kawasaki Aircraft Co., resulting in the Kawasaki C-5, company name KDC-5. It was a scaled-up, civilianised version of the Kawasaki Ki-5 fighter with enclosed seating for its two crew and single passenger. A naturally aspirated engine was chosen for reliability and greater range at lower altitude.[1]

The C-5 was a low wing cantilever monoplane with an all metal structure and a mixture of metal and fabric covering. The wings were tapered to blunted tips. The four Ki-5 prototypes had experimented with different wing roots, including an inverted gull wing but the C-5 was more conventional, though the root fairing was unusually long. Because the pilot's cockpit was over the wing, the centre section trailing edge was notched to provide a wider field of view.[1]

Both the fighter and the communications aircraft were powered by Kawasaki versions of licence-built BMW V12 engines. For high performance at height the Ki-5 used a Kawasaki Ha9-I, based on the supercharged BMW IX, but the C-5 had an unblown BMW VIII, its radiator attached to the underside of the nose. Behind the engine the upper fuselage was rounded, with a flight engineer's cockpit a little way behind the pilot; the unglazed space between them could accommodate a passenger or equipment, supplies etc. Behind the rear cockpit the upper fuselage remained high to the tail. The C-5's tailplane was mounted at the top of the main fuselage structure and braced from below. Its fin was triangular in profile, carrying a straight-edged, upright rudder. The control surfaces were unbalanced.[1]

Both models had fixed, tailwheel landing gear. The landing legs and the upper part of the wheels were enclosed in very broad trouser fairings, unusual in that behind the legs they were split into inner and outer panels that could be opened on landing to act as air brakes. The wheels had conventional brakes.[1]

Earlier experience with the Ki-5 allowed a brief testing programme for the C-5. Flying from Kagamigahara, this lasted from 17-20 February 1934. After that the C-5 was registered in the name of the Asahi Shimbun. At the time, it was the fastest Japanese civil aircraft and had the greatest range, ideal for reportage across Japan's expanding empire and of the Second Sino-Japanese War. In March 1934 a non-stop flight was planned from Osaka to Hsinking in Manchuria, now the Chinese city of Changchun, to bring news of celebrations of the anniversary of the establishment of Manchuria, though it failed when fuel froze not long after departure.[1]

Despite this failure the C-5 went on to set several Japanese speed and distance records. On 14 September 1934 it was flown by Mosaburo Niino and Kenjii Tsukagoshii from Beijing to Tokyo via Osaka, a distance of 2,630 km (1,630 mi; 1,420 nmi) in 9 hr 34 min.[1]

The C-5 was used by Asahi Shimbun alongside the biplane Kawasaki A-6, a communications modification of the experimental reconnaissance KDA-6 which shared structure with the Kawasaki Army Type 92 Fighter/KDA-5.[2]

Data from Japanese Aircraft 1910-1941[1]

General characteristics

• Crew: two, pilot and flight engineer
• Capacity: one passenger in cargo space
• Length: 9.13 m (29 ft 11 in)
• Wingspan: 13.42 m (44 ft 0 in)
• Height: 4.0 m (13 ft 1 in) tail up
• Wing area: 30 m² (320 sq ft)
• Airfoil: M-1
• Empty weight: 1,725 kg (3,803 lb)
• Gross weight: 2,860 kg (6,305 lb)
• Powerplant: 1 × Kawasaki BMW VIII water-cooled V-12
• Propellers: 2-bladed wooden

Performance

• Maximum speed: 336 km/h (209 mph, 182 kn)
• Cruise speed: 251 km/h (156 mph, 136 kn)
  
• Landing speed: 126 km/h (78 mph; 68 kn)
• Range: 1,070 km (660 mi, 580 nmi)
• Service ceiling: 7,000 m (23,000 ft)
• Time to altitude: 7.5 min to 3,000 m (9,800 ft)