# Tachikawa Ki-9

The Tachikawa Ki-9 (九五式一型練習機, Kyūgo-shiki ichigata renshuki) was an intermediate training aircraft of the Imperial Japanese Army Air Force built by Tachikawa Aircraft Company Ltd in the 1930s. It was known to the Allies under the nickname of "Spruce" during World War II. This aircraft was mistakenly identified as a Tatchikawa by the British.

## Design and development

The Ki-9 was a two-seat, unequal wingspan biplane design. Tachikawa originally planned to use the same basic airframe for both basic training and intermediate training, differentiating the two models by the use of different engines.
The prototype Ki-9 flew on 7 January 1935, powered by a 261 kW (350 hp) nine-cylinder Hitachi Ha-13a radial engine. The second prototype was identical, and the third prototype was powered by a 112 hp (80 kW) Nakajima NZ seven-cylinder radial engine. The third prototype exhibited stability problems due to a center of gravity issue, and, as a result, the primary trainer model was abandoned and the Ki-9 was developed only for the intermediate trainer. Tachikawa subsequently developed the Ki-17 for the primary trainer role. The first production aircraft were delivered in 1935.

## Operational history

The Ki-9 was introduced to service as the Army Type 95-1 Medium Grade Trainer Model A under the former aircraft naming nomenclature system. The first version had a complex, split-axle landing gear with fairings over the top of the wheels. In 1939, this was modified and simplified, the fuselage slightly shortened, and the total weight reduced. The resulting Army Type 95-1 Model B or Ki-9-kai had improved maneuverability and flight characteristics. This version was quickly superseded by the Army Type 95-1 Model C, or Ki-9-otsu, in full production.
Both versions were used widely for blind-flying training with a folding hood over the rear cockpit, and several were modified with a glazed canopy over the rear cockpit for use as a staff officer transport plane.
Some were pressed into service for use as "special attack" (kamikaze in American terminology) aircraft in the closing days of the war, fitted with either a 100 kg anti-ship bomb, an oil drum filled with explosives, or fuel in the rear cockpit.
Production by Tachikawa totaled 2,395 aircraft, ending in 1942. At least another 220 Ki-9s were constructed by Tokyo Gasu Denki (also known as Gasuden) from 1943 to 1945.
The Ki-9 was also flown in wartime by Japanese satellite countries and postwar by the fledgling government of Indonesia and captured units by the Republic of China.

## Variants

* Ki-9 (Army Type 95-1 Medium Grade Trainer Model A): Initial version two-seat intermediate trainer aircraft.
* Ki-9-ko (Army Type 95-1 Medium Grade Trainer Model B): Improved version.
* Ki-9-otsu (Army Type 95-1 Medium Grade Trainer Model C): Standard production version.

## Operators
### (World War II)
#### Japan

* Imperial Japanese Army Air Force

#### China-Nanjing

* Reorganized Republic of China Air Force

#### Manchukuo

* Manchukuo Air Force

#### Thailand

* Royal Thai Air Force

### (postwar)
#### Indonesia

* Indonesian Air Force

#### Republic of China

* Republic of China Air Force

#### South Korea

* Republic of Korea Air Force

#### North Korea

* Korean People's Army Air Force

## Specifications (Ki-9 Model A)

Data from Japanese Aircraft of the Pacific War
General characteristics
* Crew: 2
* Length: 7.9 m (25 ft 11 in)
* Wingspan: 10.32 m (33 ft 10 in)
* Height: 3.1 m (10 ft 2 in)
* Wing area: 24.5 m$^2$ (264 sq ft)
* Empty weight: 1,120 kg (2,469 lb)
* Max takeoff weight: 1,580 kg (3,483 lb)
* Powerplant: 1 × Hitachi Ha13a (Army Type 95 350hp Air Cooled Radial) 7-cylinder air-cooled radial piston engine, 195 kW (261 hp) for take-off
* Propellers: 2-bladed wooden fixed-pitch propeller
Performance
* Maximum speed: 240 km/h (150 mph, 130 kn)
* Cruise speed: 150 km/h (93 mph, 81 kn)
* Endurance: 3 hours 30 minutes
* Service ceiling: 5,800 m (19,000 ft)
* Time to altitude: 1,000 m (3,300 ft) in 4 minutes 55 seconds
* Wing loading: 58.2 kg/m$^2$ (11.9 lb/sq ft)
* Power/mass: 0.18 kW/kg (0.11 hp/lb)