As is the case with many new beginnings, the start of Dave Ronneberg's career in aviation began with a painful catalyst, the death of an older brother. In an attempt to cope with it, he decided to reach outside of himself and fulfill a childhood wish of designing his own airplane. It started as the typical school-boy combination of Spitfire/Mustang look alike using wood. Drawing on his modeling skills, he tried his hand at lofting and built a small model with some degree of success. The four-year project began as kindergarten work and progressed to a college thesis at the end.

Through this process, Ronneberg learned how to gas weld, prep and bond wood, laminate glass, and correctly use aviation hardware, among other skills too numerous to mention. By using a VariEze manual to reverse engineer, he began to understand the intricacies of composite fabrication and design. During this time, Dave was hired by Thomas Aberle of Aberle Custom Aircraft and manufactured Starduster II wings. Working with Aberle for two years, Ronneberg gained invaluable experience in rag, tube, metal, and wood construction and engine assembly techniques.

When Aberle moved his business from the LA area, Ronneberg and a friend, Arnold Dutton, then began building two VariEzes. Just after the canards were complete, word came out that the Long-EZ was available. A trip to Mohave ensued and Ronneberg bought the second set of Long-EZ plans ever sold. So the two VariEzes became Long-EZs.

From 1980 to 1983, working with his clients, Dave built three Long-EZs. In early 1983, Dave was employed by Dick Rutan for construction of Voyager. In 1984, he returned to Santa Monica and continued building Long-EZs. Liberally sprinkled amongst these projects were movie programs, cars, tooling jobs, and a stint with California Microwave manufacturing Remotely Piloted Vehicles, all the while gaining the experience necessary to evolve the Long-EZ into a moldable, manufacturable kit aircraft.

In 1987, Ronneberg started fulfilling his dream. Sam Kridell, head of Shuttle Design for North American Rockwell, used a Cray supercomputer to produce a set of full-size templates of the fuselage and bulkheads that Dave had designed over the previous five years. Using these templates, a full-size model of the fuselage was built, however the project was shelved for two years while funding was acquired.

Birth of Berkut

In 1989, construction began on the prototype bird, now called the Berkut. The model of the fuselage built in 1987 was 12" longer, 3.5" wider, and provided 4" more headroom than the Long EZ. These features were retained in the prototype Berkut. This airplane would emerge with fully retractable gear, designed by Shirl Dickey designer of the ERacer. Ronneberg acquired the rights to use Shirl's gear in the prototype and future Berkut kits and now produces the gear himself after Dickey stopped production. The prototype Berkut utilized a Lycoming IO-360 180-hp engine bumped up to 205 hp. Light Speed Engineering's Klaus Savier designed the electronic ignition.

As a side note, Berkut builder Glenn Waters installed a stock 180-hp Lycoming in his Berkut 360 as a requirement of the Popular Flying Association (PFA- kind of a cross between our EAA and FAA). With this stock engine, Glenn is seeing speeds well in excess of those in the prototype with the bumped-up engine. Glenn has a very clean, beautiful airplane.

The Berkut differs from the EZ in a number of other ways. The canopy of the Long EZ is one piece whereas the Berkut canopy is two pieces, a canopy for each person much like a fighter jet. This was incorporated to eliminate the effect of shrinkage of a canopy this size at colder temperatures, affecting the fit and seal of the canopy. The Berkut ailerons are 6" longer than on an EZ and have a 3/4" larger chord at upper surface the hinge line and 7/8" larger chord on the lower surface. The lower winglets have been eliminated by incorporating them into the wing on the Berkut. The strakes (the triangle portions between the fuselage and wing) have a convex upper surface instead of the flat surface found on the EZ.

The Berkut also makes use of carbon fiber in the design. Carbon fiber is found in the canopy frame, wing skins and spar caps, main spar caps, and canard skins and spar caps, longerons and cowls. Carbon fiber was chosen because it is four times stiffer and one-and-one-half times stronger than fiberglass by weight. The use of carbon fiber in the Berkut prevents unwanted torsional flexing in the wing, making for a much more rigid structure with no weight penalties. This, combined with the larger ailerons, also makes for a roll rate double that of a Long EZ.

The prototype Berkut was completed in the summer of 1991 and flown to Oshkosh. The reception was outstanding but Ronneberg was not ready to sell kits just yet. He used the next year to acquire financing, tooling, and materials necessary for producing kits, as well as writing a construction manual. At Oshkosh 1992, orders were taken for kits and deliveries began in January of 1993.

Races, Shows and a 540

The Berkut has had its share of race wins beginning with the prototype in July of 1992. Berkut placed first in the Jackpot Nevada EZ Bash, coming in at 240.96 mph. In 1993 at Sun n Fun, the Berkut finished first in the Class 2A race, averaging 247.19 mph from a standing start. And finally, the prototype Berkut finished its racing career where it all began, in Jackpot, Nevada placing first once again in the Unlimited Class with a speed of 245.45 mph. It also won Jackpot Races in 1996, '97 and '98.

In addition to races, Berkut entered the exciting world of air shows. The Berkut made its air show debut in Santa Ynez in the Spring of 1993. At the controls was Commander Rick Fessenden, company test pilot and ex-military F-18 pilot. Some of the most spectacular air show performances ever seen were performed by Rick who put the aircraft through its paces. Rick's performance may be seen on the Berkut video. The Berkut in air shows ended in August of 1995, when during a sustained 9G turn, Fessenden apparently experienced G-loc and did not recover. The aviation community lost a great man.

The first IO-540 was proposed for a Berkut in 1996 by a builder. It required the construction of a new engine mount, engine mount ears and new cowls by Ronneberg. This led to the IO-540 being offered as an option for the Berkut. Shortly thereafter an IO-540 was installed by Ronneberg and Misha Kasyan, whose airplane has graced the covers of many magazines in its Air Force Flight Test neon orange paint. Subsequently the IO-540 became a more popular installation on the Berkut and is now offered as the standard engine configuration, though the IO-360 is still an option for those not needing quite as much horsepower.

Berkut flew its first Reno Air Race in 1999 and finished second in the Silver Class behind a fast Glasair III and ahead of six other Glasairs, with a winning speed of 261.7 mph. The airplane was equipped with a 308-hp Lycoming IO-540 built by Ron Monson of Performance Aero Engines and turned a Klaus Savier fixed-pitch prop. Dave Ronneberg piloted the aircraft to its outstanding finish and found Berkut's excellent, unrestricted visibility to be a significant advantage throughout the race.

An All-molded Airplane

The late 1990's and early 2000 have seen improvements to the Berkut kit and components. A few highlights include redesigned landing gear constructed in-house that is also used in Shirl Dickey's ERacer. The biggest accomplishment has been the completion of tooling for molded canard and wings with winglets attached. The only foam in the airplane are the canard and wing tips. This combination not only comes in weighing less than a conventional foam wing, but stronger and faster to build. The airplane now incorporates over 100 molded components and has the best fit and finish found in any airplane in the kit industry.

Berkut Engineering, with company principals Dave Ronneberg and Vicki Cruse at the helm, promises the best Berkut kit production and company management the airplane has ever seen. 'The Berkut has seen some hard times, but we are determined to bring the airplane the audience it has deserved for a long, long time.'