An amateur plane built in 1967-1969 by Jarosław Janowski and first flown in 1970. The plane was built in a living room with an area of 18 m2 on the 2nd floor of a block of flats. Officially registered in 1976, destroyed in an accident in 1981 and then transferred to the Aviation Museum in Krakow, where it was rebuilt in 2008. In 1974, the designer modified aircraft's plans to meet American regulations regarding amateur construction. This version was designated J-1B Don Quichote. Several dozen J-1Bs were built abroad, including Czech Republic, Canada, Switzerland, Sweden and USA.