Heinonen HK-1

Juhani Heinonen, an aeronautical engineer who had previously worked for the Valmet aircraft factory at Tampere, and then for Finnair, designed a single-seat, single engined aerobatic sport aircraft, the Heinonen HK-1. It was a low winged monoplane of all-wooden construction, powered by a Walter Mikron air-cooled inline engine rated at driving a two-bladed propeller. Split flaps were fitted to the wings, while the aircraft had a fixed tailwheel undercarriage, with a steerable tailwheel but no brakes. The pilot sat under a sliding perspex canopy. A prototype was built at the glider school at Jämi, first flying in August 1954. ==Operational history==

The HK-1 was displayed at the 1955 and 1957 Ypenburg airshows. On 10 July 1957, Heinonen flew the HK-1, fitted with an additional ventral fuel tank, For this flight, Heinonen was awarded a Louis Blériot medal by the Fédération Aéronautique Internationale. This record was not broken until 3 July 1984. The aircraft is now preserved at the Finnish Aviation Museum near Helsinki Airport. ==Specifications==