The Nakajima Ki-34 Army Type 97 Transport was a twin-engined light transport that was originally developed as a smaller version of the Douglas DC-2 for use on short range, low traffic civil airline routes.
In 1935, after purchasing a license to build the Douglas DC-2, Nakajima decided to design their own smaller transport aircraft. The task was given to Engineer Akegawa, and the aircraft was designated as the Nakajima Aerial Transport No.1 (AT-1).
Akegawa took inspiration from several existing aircraft. The biggest influence was the Douglas DC-2. Nakajima also gained valuable information on retractable undercarriages from a study of an imported Northrop 5D.
The overall layout of the aircraft was similar to the DC-2, with a flat sided fuselage, low-mounted wing and twin engines. As on the DC-2 the wings were flat in the centre section and had a slight dihedral on the outer panels. The Nakajima aircraft was significantly smaller than the DC-2 - it was nearly 12ft shorter and the wing span was 20ft smaller. Empty weight was nearly 5,000lb lighter and loaded weight 7,000lb lighter. Cruising speed was almost the same, but the normal range was 745 miles, down from 1,000 miles on the DC-2. The wings had a different plan - on the DC-2 the trailing edge and the inner section of the leading edge were both level while the leading edge of the outer wing panels tapered back towards the wing tip. On the Nakajima aircraft both the leading and trailing edges tapered equally along their entire length, with more taper on the leading edge.
The prototype was completed on 1936, by which time it had been redesignated as the Nakajima AT-2, Akegawa Transport No.2. It made its maiden flight on 12 September 1936. The new aircraft was stable and its performance was good. The only problems were fairly minor and the type was ordered by Dai Nippon Koku K.K. (Greater Japan Air Lines Co Ltd) and Manchurian Airlines. Thirty-two civil AT-2s were built between 1937 and 1940 and they remained in use until 1945.
The prototype was powered by two 580hp Nakajima Kotobuki 2-I radials with two-blade propellers, but civil production aircraft were given two 710hp Nakajima Kotobuki 41 engines.
In 1937 the Japanese Army decided to adopt the AT-2 as a paratroop transport and communication machine. The Army aircraft were powered by 710hp Nakajima Ha-1b engines with smooth NACA-type cowlings. They were given the designation Army Type 97 Transport or Ki-34.
Nakajima produced nineteen Ki-34s for the army between 1937 and 1940. Production then switched to Tachikawa Hikoki K.K., which built the bulk of the machines - 299 between 1938 and the end of production in 1942. Most of these aircraft were used by the Army but some did go to the Japanese Navy, where they became the Nakajima L1N1 Navy Type AT-2 Transport.
Engine: Two Nakajima Ha-1b nine-cylinder air cooled radials
Crew: 3 plus 8 passengers
Span: 65ft 0 1/8in
Length: 50ft 2 3/8in
Height: 13ft 7 3/8in
Empty weight: 7,716lb
Loaded weight: 11,574lb
Max speed: 224mph at 11,025ft
Cruising speed: 193mph
Climb Rate: 6min 18sec to 9,840ft
Service ceiling: 22,965ft
Range: 745 miles