Aircraft overview

The FK-Lightplanes FK12 Comet is a two-seat, tandem biplane designed by Peter Funk and produced by FK-Lightplanes in Germany from the late 1990s onward. It sits in the European ultralight and light-sport-style category, but its configuration is unusual: a compact, modern biplane with strut-braced wings, composite and metal construction, and sporty handling rather than a purely touring focus. The type is distinct from FK-Lightplanes’ high-wing FK9 and low-wing FK14 Polaris; the FK12 Comet is the company’s open-cockpit, vintage-inspired sport biplane.

Performance & specifications

Most FK-Lightplanes FK12 Comet aircraft are powered by Rotax 912-series engines, commonly the 80 hp Rotax 912 UL or 100 hp Rotax 912 ULS, with installation details depending on year and local certification rules. Typical cruise speeds are in the region of 80-95 knots, with economical operation and short-field capability being more relevant than high-speed cross-country performance. Depending on fuel fit, engine, propeller, and national weight category, range is commonly several hundred nautical miles rather than a long-distance touring figure. Many examples were built to European ultralight maximum takeoff weights around 450-472.5 kg, so useful load must be checked aircraft by aircraft. Service ceiling figures vary by engine and propeller installation, but the type is generally operated as a day-VFR recreational aircraft rather than a high-altitude traveller.

Cabin & avionics

The FK-Lightplanes FK12 Comet has tandem seating, with the pilot and passenger seated one behind the other under individual windshields or, on some aircraft, canopy arrangements depending on build and equipment. The cockpit is narrow and sport-oriented, with good outside visibility and a more exposed flying experience than enclosed touring ultralights. Avionics are usually simple VFR installations: airspeed, altitude, engine monitoring, compass or GPS, and a VHF radio/transponder where required. Later or upgraded examples may have compact EFIS units from suppliers such as Dynon, MGL, or Garmin portable-panel equipment, but integrated suites such as Garmin Perspective or G1000 are not typical for this aircraft.

Buying & value

Used FK-Lightplanes FK12 Comet aircraft appeal to buyers wanting a distinctive recreational biplane with Rotax operating economics. Inspection should focus on airframe condition, wing attachment points, struts, control linkages, fabric or covering condition where applicable, landing gear, propeller, and evidence of ground loops or hard landings. Engine logbooks, gearbox service history, carburetor maintenance, and compliance with Rotax service bulletins are important. Buyers should verify the exact national certification category, permitted weights, and whether aerobatic or manoeuvre limitations apply to that individual aircraft. Common differences include engine choice, propeller type, instrument upgrades, cockpit covering, and ballistic parachute fit. In the used market, the FK-Lightplanes FK12 Comet is positioned as a niche sport aircraft rather than a utility trainer or fast tourer.