How do you design a street-legal, FAA-approved flying car that has a chance at commercial success? Samuel Schweighart, the co-founder and VP of engineering at Terrafugia, has a pretty good idea. Schweighart is one of the brains behind the Transition, a $250,000 flying car set to be released in late 2011.

The bulk of the Transition’s engineering work was performed in SolidWorks, a 3-D CAD design program. Schweighart used the software to make components fit correctly in the vehicle, to ensure enough room for range

clearances, and analyze metal parts for strength. “Essentially we built the plane in SolidWorks before building it in real life,” Schweighart says.

Designing the Transition–essentially, a plane that can switch to driving mode in just 30 seconds–wasn’t easy, Schweighart says. “Designing a strong, crashworthy lightweight vehicle is an engineering challenge and taking a standard car and making it fly takes optimized components.” But after a year of designing the Transition prototype from a proof of concept, Schweighart is confident that the vehicle will be ready to go next year.

A word of advice for future Transition owners: If you get into an accident on the highway, take the vehicle to your local aircraft mechanic. “They will have to do inspection to make sure the plane is in shape,” Schweighart says.

Ariel Schwartz can be reached on Twitter or by email.