Kolb Firefly

The Firefly is a single seat, F.A.R. Part 103 ultralight, powered by a 40-HP Rotax 447 in a pusher configuration. Distributed in kit form by the New Kolb Aircraft Co.

As a "low-inertia" vehicle, it''s flight characteristics are somewhat different from the common single-engine Pipers, Cessnas, etc. Initial takeoff acceleration is quite brisk, with speed increasing very rapidly and throttle application requiring some care due to the above-centerline engine mounting causing a tendency to nose over if applied too quickly. With normal throttle application, by the time it is fully open, the Firefly is at takeoff speed. Takeoff rolls are thus very short, with 150' being the quoted book value.

Control response once airborne is typical stick and rudder; few surprises. It is a docile, stable craft, and if rigged correctly will fly hands-off at the airspeed where natural trim occurs.

The Firefly is no glider, and with the flaperons fully extended, it will descend rather steeply - similar to an old Cessna 150 with 40 degrees of flaps. However, there is absolutely no float upon flaring for landing, and the Firefly settles (stalls) immediately upon removal of power. This was the most surprising feature of this aircraft, and requires a somewhat different landing technique than the one accustomed to by the typical Cessna pilot: power is carried to touchdown, removing it only as the wheels touch down. If the landing flare is started 10-15 feet above the runway with power removed, the Firefly will likely stall and drop from that height with bent landing gear being the result.

Taxiing is straightforward and easy with the steerable tailwheel. Visibility is exceptional without an engine and propeller to block the view. The Firefly can be flown with a short, motorcycle-style windshield or a full, wrap-around windshield that complete encloses the pilot from the front, top, and sides of the cockpit.

External Links

New Kolb Aircraft Co.

Design and development

The Firefly is a development of the Kolb Firestar and was designed to comply with the American FAR 103 ultralight regulations, including that category's maximum 254 lb (115 kg) empty weight.

The Firefly was intended to be a ''FAR 103'' legal ultralight that was powered by the heavier Rotax 447 engine. The Rotax 277 28 hp engine was also an option when the aircraft was first offered.

The design features a forward fuselage of welded 4130 steel tubing, mated to an aluminum tailboom. The horizontal stabilizer, tail fin and wings are also constructed of riveted aluminum tubing with all flying surfaces covered in doped aircraft fabric. The wings are quick-folding for storage and ground transport.

The factory kit options include a complete cockpit enclosure, brakes, quick build option, Ballistic Recovery Systems parachute and steel tube powder coating.