| Koken | |
|---|---|
| |
| Role | Long range research aircraft |
| National origin | Japan |
| Manufacturer | Gasuden |
| First flight | 25 May 1937 |
| Number built | 1 |
The Gasuden Koken (also known as the Kōken-ki (航研機)) was a Japanese long-range research aircraft of the 1930s. It was designed by the Aeronautical Research Institute of Tokyo Imperial University and built by the Tokyo Gas and Electric Industry (also known as Gasuden), to break the world record for longest flight, setting a closed circuit world record of 11,651.011 km (7,240 mi) in March 1938.