Regularly breeding new, bright yellow airplanes from its tidy three-hangar hive on the east side of Wittman Regional Airport, Sonex Aircraft has sustained and supported fun flying worldwide with its economical, efficient kit aircraft since 1998.
The newest member of the family is the SubSonex, a single-seat jet. With its testing and development complete, it leaves the e-Flight Initiative, which is developing a practical, electric-powered sport airplane, as the sole resident of the Hornets’ Nest, the company’s research and development area.
Sonex is a family business. Founded by President John Monnett, led by his son, CEO Jeremy, whose mother, Chief Financial Officer Betty, keeps and eye on both of them, says General Manager Mark Schaible with a smile.
The Sonex family tree is much more extensive, with each of the company’s 12 employees connected to its customers. Many of them come to Wittman each year for builder’s workshops, transition training, and the annual Sonex Open House held before EAA AirVenture.
The aircraft family started with the eponymous Sonex, an easy-to-build two-seater powered by an 80-hp AeroVee engine, a VW-based powerplant developed and marketed by Aero Conversions. A subsidiary of Sonex, its product line includes hydraulic brakes, throttle quadrants, and engine cooling kits for members of the Sonex family of airplanes.
The other kits in the family are the Waiex, a two-seat side-by-side Sonex with Y-shaped tail feathers, the Xenos motorglider, and the single-seat Onex, which has folding wings and joined the family in 2011.
The parts that unite to create the different Sonex aircraft are designed in-house but manufactured by other companies, many of them in Wisconsin, that have the aviation tooling and infrastructure to efficiently and economically produce them. The different airplanes share a number of common parts, and Sonex compiles and ships all of them in wooden crates and plastic-wrapped pallets from its warehouse hangar.
Airplanes designed by the always-working mind of John Monnett are on display at the Udvar-Hazy National Air & Space Museum, the EAA AirVenture Museum, and in the Wittman Regional Airport Terminal.
Steve Wittman is indirectly responsible for Sonex Aircraft. In 1968, at EAA Rockford, John Monnett (at right) attended the seminar Wittman gave on the Formula V racers. In time, the two became fast—and competitive—friends. John called his single-seat VW-powered racer the Sonerai, which debuted at EAA Oshkosh in 1971.
John and Betty established the Monnett Experimental Aircraft Co. to market the designs. When the company outgrew its first facility in Elgin, Illinois, it moved to Oshkosh in 1981 and built a bigger one at Wittman, now occupied by CR Meyer. The company didn’t survive the general aviation slump of the 1980s that affected all manufacturers, Cessna, Beech, and Piper included.
From its founding 16 years ago, Sonex has been very involved in both the aviation and local community. In addition to its builder’s workshops and open house at Wittman, it connects with others at two recreational aviation shows in Florida and through a series of educational videos on its website. An active participant in the efforts to create the Wittman Airport business park and other efforts, it regularly opens its doors to chamber activities, such as morning networking gatherings because they, too, are part of the family.