Sonex Aircraft
| Company type | Private |
|---|---|
| Industry | Aerospace |
| Founded | 1998 |
| Founder | John Monnett |
| Headquarters | Oshkosh , United States |
Area served | Worldwide |
Key people | Mark Schaible (owner and president) |
| Products | All-metal kit aircraft for homebuilders |
Number of employees | 9 |
| Parent | Sonex LLC |
Sonex Aircraft, LLC is a privately held American enterprise headquartered in Oshkosh, Wisconsin, specializing in the manufacture of all-metal kit aircraft for homebuilders. Established in 1998 by engineer and entrepreneur John Monnett, the firm continues the tradition of his earlier designs, including the Monnett Sonerai sport aircraft series, the Monnett Monerai sailplane, the Monnett Moni motorglider, and the Monnett Monex racing airplane.
History
In 2006, Sonex broadened its operations by opening a flight center alongside a 5,600 square foot warehouse dedicated to parts distribution, supporting its expanding customer base. By 2013, the FAA National Kit Evaluation Team had granted approval for fast-build kits complying with the "51% rule" for Sonex’s Sonex, Waiex, and Onex models, providing a competitive edge through reduced construction time.
The company encountered leadership difficulties after the passing of CEO Jeremy Monnett, son of the founder, in 2015. In 2018, John Monnett revealed his intention to retire and transfer ownership of Sonex Aircraft. This transition culminated in January 2022 when Mark Schaible, a longtime employee and general manager, purchased the company’s assets. Schaible established Sonex LLC and took on the roles of owner and president, ensuring steady leadership and ongoing business development.
In December 2019, Sonex augmented its product range by acquiring the Sonerai kit aircraft line designed by John Monnett himself, strengthening its position in the homebuilt sport plane market. The company’s commitment to innovation was further demonstrated with the introduction of a prototype high-wing aircraft in 2024, reflecting sustained investment in product advancement and international outreach.
Sonex operates primarily through sales of kit aircraft complemented by a dedicated parts distribution network managed via its subsidiary AeroConversions engines. Employing a compact team of nine staff members, Sonex maintains a significant role within the aerospace sector, catering to aviation hobbyists and builders worldwide.
Aircraft
| Model name | First flight | Number built | Type |
|---|---|---|---|
| Sonerai | 1971 | Low-wing homebuilt airplane powered by a single piston engine | |
| Sonex | 2000 (customer assembled) | 500 by 2014 | Low-wing homebuilt airplane with single piston engine |
| Waiex | 2003 | Low-wing homebuilt airplane powered by one piston engine | |
| Xenos | 2003 | Low-wing homebuilt motor glider with single piston engine | |
| Onex | 2011 | Low-wing homebuilt airplane driven by one piston engine | |
| ESA | Single electric motor low-wing homebuilt aircraft (unbuilt) | ||
| SubSonex JSX-1 | 2011 | Low-wing homebuilt airplane powered by a single jet engine | |
| SubSonex JSX-2 | 2014 | Low-wing homebuilt airplane with one jet engine | |
| Teros | 2015 | Low-wing unmanned aerial vehicle powered by a single piston engine | |
| Sierra Hotel | High-wing homebuilt airplane with single piston engine |
Engines
AeroConversions, a subsidiary of Sonex LLC, manufactures the AeroVee Engine, a specialized aircraft powerplant derived from the Volkswagen air-cooled engine design.
Hornet's Nest
Hornet's Nest serves as Sonex LLC’s dedicated research and development branch, concentrating on pioneering advancements in aviation technology.
E-flight
During the 2007 EAA AirVenture Oshkosh event, Sonex unveiled the E-flight initiative aimed at investigating electric propulsion, ethanol-based fuels, and alternative engine systems. By December 2010, an all-electric Waiex successfully took flight at Wittman Field, utilizing a 54 kW brushless DC motor combined with lithium polymer batteries. This setup provided approximately one hour of cruising endurance or 15 minutes of aerobatic performance. The accomplishments of this endeavor established the foundation for the Sonex Electric Sport Aircraft and underscored Sonex’s prominent role in advancing electric aviation technologies.