Science & Technology Agency Asuka
The Asuka, which first flew in October 1985, is a derivative of the Kawasaki C-1 tactical transport. The original P&W JT8D engines have been replaced by four Ishikawajima-Harima Heavy Industries FJR710/600S high bypass ratio turbofans.
The engines are mounted above and ahead of the wing leading edges. The exhaust airflow is directed across the wing extrados and attaches to the trailing edge flaps in whathas been termed “Upper Surface Blowing”. The resulting depression caused by the Coanda effect produces the desired lift force.
The STOL conversion takeoff run to 15m on the first flight was 509m, including a 394m ground run. Takeoff speed was 72 kts. The landing run from 15 m was 439 m, including 320 m on the ground.
STA claims the plane is only experimental and that there are no immediate development prospects.