The Kolb King Kolbra is a kit-built, tandem two-seat ultralight landplane developed by New Kolb Aircraft in London, Kentucky. Designed primarily for the training role and recreational aviation, the aircraft is a hybrid that synthesizes components from several existing Kolb designs. It utilizes wings and a tail from the Mark III, a nose derived from the FireStar, and landing gear based on the Slingshot model. The King Kolbra variant is specifically distinguished from the baseline Kolbra by its broader nose and the standard implementation of a more powerful engine.
Production of the broader Kolbra family began with a prototype (registration N718KA) that first flew on May 7, 2000. The aircraft was publicly announced and debuted at the EAA AirVenture show in Oshkosh in July 2000. While the exact number of King Kolbra units produced is unknown, records from mid-2002 indicate that over 50 Kolbra kits had been sold and 12 aircraft were flying. By 2003, historical snapshots listed two King Kolbras and two Kolbras as completed.
The aircraft's design is attributed to the organization founded by Homer Kolb, who began designing ultralights in 1970 and formally established the Kolb Aircraft Company in 1980. A hallmark of the design is its welded 4130 chromoly steel fuselage cage, featuring a 152 mm (6 in) diameter rear fuselage tube and spar for increased strength. For ease of storage and transport, the aircraft features folding wings and a folding tail. To enhance low-speed control and STOL capabilities, the wings are equipped with full-span flaperons.
While the baseline Kolbra typically utilizes a 64 hp Rotax 582 UL two-stroke engine, the King Kolbra is standardly powered by an 80 hp Jabiru 2200 four-cylinder, four-stroke piston engine. The airframe is also compatible with other powerplants, including the Rotax 912 UL and 912 ULS. In terms of performance, the baseline model reaches a maximum speed of 100 mph and a cruise speed of 75 mph, with a stall speed of 35 mph and a rate of climb of 1,000 ft/min. The aircraft has a gross weight of 1,000 lb and a fuel capacity of 10 US gallons.
Throughout its service, the King Kolbra has remained a civilian aircraft operated by private owners and flying clubs. The manufacturer, now operating as Kolb Aircraft LLC or New Kolb Aircraft, continues to produce kits in Kentucky, having resumed production after an EF-4 tornado destroyed its main facility. The company reports that over 8,000 Kolb aircraft of various types are currently in existence worldwide.