The Mitsubishi Army Type Ki 1 Trainer was a licence-built version of the Hanriot HD-14 that served as the main basic trainer in the Japanese Army from the mid-1920s until the mid-1930s.
In 1919 the Japanese army had imported a number of Nieuport 81-E2s, which were used as basic trainers. The type was produced under licence by Mitsubishi as the Army Type Ko 1 Trainer in the early 1920s, and remained in service until 1926.
The Hanriot HD-14 was a twin-bay biplane of conventional construction for the period. It had a wooden structure, and was mainly fabric covered although some key parts were plywood or metal covered. Its most unusual feature was its main undercarriage, which had four main wheels in two pairs.
In its search for a better basic trainer the Japanese Army purchased a number of HD-14s. The Hanriot aircraft had lower wing loading than the existing Nieuport type, and was thus more stable. It also handled well with no power. The Army considered it to be a better basic trainer than the Ko 1, and so in February 1923 Mitsubishi purchased a licence to produce the HD-14 in Japan. The Japanese aircraft used a different engine, and had some minor internal differences, but were otherwise identical to the French original. The first Mitsubishi produced aircraft was ready in March 1924 and the type was soon accepted by the Japanese Army as the Ki 1. It entered service in 1924, and wasn't replaced until 1935 when the Tachikawa Type 93-3 (code-name Cedar) entered service. Mitsubishi built 145 aircraft between 1924 and 1927.
After leaving military service a number of Ki 1s were sold to civil flying schools in Japan, where rather confusingly they were designated as the Hanriot 28.
The Ki 1 designation wasn't related to the later system of Kitai numbers, but instead came from a 1921 designation system in which each foreign aircraft manufacturer was given a single kanji character as a code. Hanriot was allocated 'Ki', and each Hanriot aircraft produced in Japan was given a consecutive number. The Hanriot HD-14 was the first aircraft in this sequence, and thus became the Ki 1. Later on the Kitai system was adopted. Kitai is a two-character word meaning airframe. 'Ki', the first letter of the word, was adopted as the abbreviation for Kitai. Just to add to the confusion the Ki-1 under the Kitai system was also a Mitsubishi aircraft, in this case the Army Type 93 Heavy Bomber.
Engine: Le Rhône nine-cylinder air cooled rotary engine
Span: 33ft 8in
Length: 23ft 4 3/4in
Empty weight: 1,212lb
Loaded weight: 1,763lb
Max speed: 72mph at 6,561ft
Cruising speed: 50mph
Climb Rate: 15 minutes to 6,561ft
Service ceiling: 13,123ft
Range: 150 miles