FK9

The B&F FK9 is one of the most successful and widely built German ultralight aircraft of all time. Designed by Otto and Peter Funk, this shoulder-wing aircraft in mixed construction made its first flight in 1989 and was introduced at the Aero trade fair in Friedrichshafen that same year. Since then, over 500 FK9s have been built and are flying on four continents. The FK9 has become particularly established as a training aircraft at numerous German flight schools.

The FK9 is a strut-braced shoulder-wing aircraft with a steel tube fuselage and fabric-covered wings. Depending on the version, it is powered by a Rotax 912 UL (80 hp), Rotax 912 ULS (100 hp), or Rotax 912 iS with fuel injection. With the 100 hp engine, the FK9 achieves a cruise speed of 170–196 km/h at a consumption of only 15 liters per hour. The stall speed is a docile 64 km/h, and the takeoff and landing roll is just 150–200 meters. From the Mark I to the current Mark VI, the design has been continuously improved.

Buyers looking for a used FK9 will find a broad selection on the German market. Older Mark II models start from around EUR 20,000–25,000, a well-maintained Mark IV typically costs EUR 35,000–50,000, and newer Mark V or Mark VI models with good equipment trade for EUR 55,000–95,000.

The FK9's greatest strengths are its forgiving flight characteristics with excellent slow-flight capability, low operating and maintenance costs, robust and easy-to-repair construction, and the large installed base which ensures good parts availability. Weaknesses include slightly higher maintenance demands on the fabric covering compared to all-metal or composite ultralights, lower cruise speeds compared to faster low-wing designs, and a rather cramped cockpit in older versions.

The FK9 is the ideal choice for beginners, student pilots, and club members looking for a reliable, affordable, and extremely forgiving ultralight. Thanks to its low purchase price, it is often the perfect entry point into ultralight aviation.