In the Air International Issue for September 1973, there was mention made of an experimental light helicopter. The project was proposed by the Japanese Defense Agency. The specifications were a gross weight of 4410lb (2000 kg) and a speed in the order of 193 mph (310 km/h). Power was to come from a turboshaft in the 600shp class. Dynamic component studies were said to have been carried out by the time of the report, and it was planned for the prototype to fly either late in 1975 or early 1976. The long term plan was to use the data gathered from the small experimental helicopter, to assist the build of a larger helicopter to fulfil the ASW role for the JMSDF. It was envisaged that total cost of the project would be in the region of £30-40 million (obviously its equivalent at that time in yen!!)
The planned primary armament would have been Mark 44 Torpedoes (initially supplied under the MAP and then subsequently manufactured under licence in modest numbers by Mitsubishi at Nagasaki) and the Type 73 lightweight torpedo, also produced by Mitsubishi (developed by the Defense Agency's TRDI) and which was just about to enter service, though production would be in penny packets for quite some time due to the Finance Ministry.