Sonex Aircraft

Sonex Aircraft, LLC
TypePrivate
IndustryAerospace
Founded1998
FounderJohn Monnett
HeadquartersOshkosh, Wisconsin, United States
Key people
  • Jeremy Monnett
    (Former CEO)
  • Mark Schaible
    (CEO)
Number of employees
9
SubsidiariesAeroConversions engines
Websitesonexaircraft.com

Sonex Aircraft, LLC is an American kit aircraft manufacturer located in Oshkosh, Wisconsin, producing kits for four all-metal homebuilt monoplanes. The company was founded in 1998 by John Monnett, who has designed the Monnett Sonerai sport aircraft series, Monnett Monerai sailplane, Monnett Moni motorglider, and Monnett Monex racer. Approximately 700 Sonex aircraft were reported flying by early 2026.

History

Sonerai IILS

The company was founded by John Monnett in 1998.

The company opened a flight center and a 5,600 sq ft (520 m2) parts distribution warehouse in 2006. The following year, it displayed an electrically powered version of its Sonex aircraft.

In 2013, the FAA National Kit Evaluation Team (NKET) approved fast-build "51% rule" versions of the Sonex, Waiex, and Onex.

Sonex CEO, Jeremy Monnett, the son of founder John Monnett Jr. was killed in the crash of a Sonex SA in 2015.

In June 2018, John Monnett announced his plan to retire and sell the company. In January 2022, Sonex employee and general manager, Mark Schaible, purchased the assets of Sonex Aircraft LLC and Sonex Aerospace LLC, forming them into a new company, Sonex LLC. Schaible was the owner and president of the new company.

In December 2019 the John Monnett-designed Sonerai was acquired by Sonex Aircraft.

The company rolled out a prototype highwing aircraft in 2024.

In March 2026, bankruptcy of both Sonex LLC and Schaible were announced – with a last-minute offer to sell the company – citing rising costs, a severe downturn in sales, competition from their own used aircraft, cashflow issues, and bank pressure. However, by June the company had restarted production.

Products

Aircraft

Sub Sonex JSX-1
Sonex Onex
Model name First flight Number built Type
Sonerai 1971 Single piston engine low-wing homebuilt airplane
Sonex 2000 (customer built) 500 by 2014 Single piston engine low-wing homebuilt airplane
Waiex 2003 Single piston engine low-wing homebuilt airplane with Y-tail
Xenos 2003 Single piston engine low-wing homebuilt motor glider
Onex 2011 Single piston engine single-seat low-wing homebuilt airplane
ESA Unbuilt single electric engine low-wing homebuilt airplane
SubSonex JSX-1 2011 Single jet engine low-wing homebuilt airplane
SubSonex JSX-2 2014 Single jet engine low-wing homebuilt airplane
Teros 2015 Single piston engine low-wing unmanned aerial vehicle
Sierra Hotel Single piston engine high-wing homebuilt airplane

Engines

Company subsidiary AeroConversions manufactures the AeroConversions AeroVee Engine, a custom aircraft implementation of the Volkswagen air-cooled engine.

Hornet's Nest

Sonex at Cotswold Airport, Gloucestershire, England, 2016

The Hornet's Nest is the research and development arm of Sonex LLC.

E-flight

At AirVenture 2007, Sonex Aircraft announced a project to work on innovative technologies in aviation. The E-flight projects includes using an electric motor, ethanol-based fuels, and other power plant alternatives. In December 2010, an all-electric Waiex was test flown from Wittman Field in Oshkosh, Wisconsin. The aircraft was flown with a 54 kW (72 hp) brushless DC electric motor, managed by a newly designed controller. Power is from a collection of 14.5 kW-hour lithium polymer batteries, giving the aircraft an endurance of one hour at low-speed cruise or 15 minutes of aerobatics. This was the beginning of the development of the Sonex Electric Sport Aircraft.

References

Footnotes

  1. ↑ Monnet had previously owned another company, Monnet Experimental Aircraft, from 1972 to 1986. By May 1995, he had also established Sky Struck Enterprises, which offered seminars on homebuilt aircraft construction. The latter would eventually be used to market the Sonex aircraft design before the eponymous company was founded.

Notes

  1. 1 2 3 McMillin, Molly: "Sonex Kit Plane Builder Closes Doors," March 31, 2026, The Weekly of Business Aviation / Aviation Week, retrieved April 1, 2023
  2. 1 2 Kate, O'Connor (June 6, 2018). "Sonex For Sale". AVweb. Archived from the original on July 19, 2018. Retrieved August 19, 2026.
  3. ↑ Storm, Sheila (May 21, 1995). "Sky Struck on Runway for Takeoff". Oshkosh Northwestern. p. D1. Retrieved August 19, 2026.
  4. ↑ Draeger, Carol (July 28, 1997). "Fit for the Sky". Oshkosh Northwestern. p. D1. Retrieved August 19, 2026.
  5. ↑ "Sonex Aircraft News Archive January-February, 2007". Sonex. January–February 2007. Retrieved July 29, 2024.
  6. ↑ "Sonex Aircraft Unveils Electrically-Powered Proof of Concept SportPlane". Aero-News Network. July 24, 2007. Retrieved August 19, 2026.
  7. ↑ "Sonex Offers Quick-Build Kits Featuring Prebuilt Major Assemblies". Retrieved July 22, 2013.
  8. ↑ "Sonex CEO Jeremy Monnett Killed in Aircraft Accident". AOPA. June 3, 2015. Retrieved August 19, 2026.
  9. ↑ Phelps, Mark (January 4, 2022). "Longtime Employee Acquires Sonex Assets; All Staff Retained". AVweb. Retrieved January 5, 2022.{{cite web}}: CS1 maint: deprecated archival service (link)
  10. ↑ Cook, Marc (December 30, 2019). "Sonerai Kit Aircraft Comes Home". AVweb. Archived from the original on January 2, 2020. Retrieved December 15, 2019.
  11. ↑ Fores, Kerry (July 21, 2024). "Sonex Rolls Out Highwing Protoype". Kitplanes. Retrieved July 29, 2024.
  12. ↑ "Sonex Announcement 032726". Retrieved March 27, 2026.
  13. ↑ Godlewski, Meg (June 12, 2026). "Once-Shuttered Sonex Now Fully Operational". Flying. Retrieved August 19, 2026.
  14. ↑ "Sonex reports 500th completion". Sport Aviation: 14. January 2015.
  15. ↑ Cook, Marc (February 16, 2023). "Sonex Introduces "Sierra Hotel" Highwing". AVweb. Retrieved February 17, 2023.{{cite web}}: CS1 maint: deprecated archival service (link)
  16. ↑ "Another Secret is Out". AirVenture. Archived from the original on September 27, 2007. Retrieved August 19, 2026.
  17. ↑ Horne, Thomas A. (December 6, 2010). "Sonex Electric-Powered Waiex Makes First Flight". AOPA. Retrieved August 19, 2026.
  18. ↑ Pew, Glenn (December 2010). "Sonex Flies Electric Airplane". AvWeb. Retrieved December 6, 2010.
  19. ↑ "e-Flight ESA". Sonex. Archived from the original on December 5, 2011. Retrieved August 19, 2026.