Homebuilt Jet

After some teething issues on the development side, Sonex Aircraft’s SubSonex jet has finally flown. The tiny single-seat jet completed a 14 minute first flight in Oshkosh, Wisconsin last week. The first flight was successful according to company founder and SubSonex designer John Monnett. He says the jet project will continue and there are still hopes to offer it as a kit to customers.

“We have a test flight plan to expand the envelope of the aircraft” Monnett said. “We’ll see where the project takes us from here.”

Wasting no time, the SubSonex completed five more flights in the two days following its first flight. So far all of the flights have been made by Bob Carlton who flies a jet powered glider in front of the crowds each year at Airventure in Oshkosh, Wisconsin. Sonex is also based in Oshkosh. The SubSonex uses the same, Czech built, PBS TJ-100 jet engine used by Carlton on his glider. The tiny engine produces 240 pounds of thrust.

With the conservative first flight out of the way, Sonex’s Mark Schaible says Carlton did some moderate envelope expansion on the subsequent flights, “exploring higher power settings and climb rates.”

No word yet on what kind of climb rates are being seen in the lightweight jet.

Schaible says there will be changes made to the prototype before the final design is set. Some ideas include aerodynamic enhancements that should add to the performance.

“John [Monnett] has talked about retracting the nose wheel, to clean it up a bit.”

The SubSonex is the latest airplane developed by the veteran airplane designer. Monnett first made a name for himself designing in expensive and efficient homebuilt airplanes that used Volkswagen engines. In the decades since he has built a successful business that includes many one and two seat designs aimed at the sport pilot who wants good flying performance – including aerobatics – on a budget.

Calling the SubSonex his “Walter Mitty project, ” Monnett plans to offer the airplane as a homebuilt kit like other aircraft in the Sonex family. With plenty of development still left to finish, a price hasn’t been set for the single seat jet. Similar aircraft powered by the company’s new VW based engines cost less than $25, 000. The price of the jet engine is likely to be the big variable with the SubSonex.