When Steve Saint asked the Waodani Indians of Ecuador - the same tribe that killed his missionary father in 1956 - how he could help them some years ago, they mentioned the concept of a flying machine.
He never forgot the idea and earlier this week drove through Chattanooga with the Maverick Sport Flying Car he helped engineer and which he intends the South American tribe will have one day.
"It's meeting people where they feel the need," said Mr. Swift, who established the nonprofit Indigenous People's Technology and Education Center (I-TEC) that assists the "hidden church" toward independence, self-sustenance and maturity.
The flying car is just that - an actual road legal car with a wing deployment system like a paraglider that would allow it to fly over the Amazon River Basin jungles to reach the area in which the Waodani live.
"There are no roads," said Mr. Saint, author of "The End of the Spear" and inspiration for the 2006 movie by the same name, "and they have 30 feet of rain a year."
Ultimately, he envisions indigenous people everywhere having such a craft - they can learn to operate it in six hours, he says - that would allow them to fly their sickest people into areas where they could receive medical help.
Troy Townsend, vice president of I-TEC and one of the Maverick's test pilots, said "our dream" is to commercially sell five of the crafts so they can sell at cost a sixth to the people who need it.
The craft they designed, he said, needed to be "ground driveable (but) would also fly." On the ground, it needed to be rugged enough to "handle terrain like a dune buggy."
What Mr. Saint drove into the Tennessee Welcome Center at East Ridge was the result of seven years of research and development, I-TEC officials said. The present $80,000 model is the fourth prototype, the last one having been disassembled at the end of 2009 and rebuilt this year from the ground up.
The Florida-licensed craft that arrived in a caravan of three vehicles en route to AirVenture Oshkosh, an international annual gathering in Oshkosh, Wis., for aviation enthusiasts, resembled a black dune buggy with a propeller protruding from its rear.
Powered by a 2.2-liter Subaru engine, it has a 15-foot-long body made of a light carbon fiber on a tube frame, weighs less than the 1,320-pound weight limit of a Light Sport Aircraft (LSA), has a 14-gallon gas tank, seats three adults, and has air conditioning and cruise control.
"It's comfortable to drive on the highway," Townsend said.
The engine, the 75-inch, belt-driven propeller, and the 36-foot-wide, nonstructured, elliptical wing - which stores beneath a zippered unit on top of the car - enable the car to fly. It can take off in about the length of a football field.
Pilots use the car's steering wheel to direct it in the air at elevations of 500 to 1,000 feet. They press down the accelerator to ascend - and cruise up to about 40 miles per hour - and let off the accelerator to descend.
Although it has passed official LSA testing, it doesn't have Federal Aviation Administration approval yet and has been flown only in a Florida testing area.
Mr. Saint said the FAA doesn't quite know what to make of it and how it fits within its rules.
"We're pioneering a whole new aircraft," he said.
Mr. Townsend said if the car had its wings out and propeller going as it cruised north on Interstate 75, it would take off when it reached a high enough speed.
That sounded good to Don Gibson of Villa Rica, Ga., who was accompanying a tractor truck carrying concrete and who is used to driving 18-wheelers himself.
"It's amazing," he said while stopped at the Welcome Center. "That would be all right, wouldn't it? You get in traffic, you could fly right out of it."
Townsend said there have been other flying cars - built by Moller and Terrafugia - but he believes the Maverick Sport is the first flying car to drive across the country.
It's hardly a cobbled together contraption, though. The design won the 2009 Popular Mechanics Breakthrough Award.
Mr. Saint said he's anxious to get the craft into production in order to get the cost down.
"It's entirely possible this time next year it could be in production," he said.
In turn, Mr. Saint said, the Maverick Sport he drove through town this week would go to the Waodani Indians.
"They're waiting for it," he said.
Then, he said, the Waodani, among which he grew up, would have another tool to help others.
That would help fulfill the biblical Great Commission, which Saint said often has been misunderstood.
It's not, he said, "to go and do anything for everybody forever" but to make disciples so people can pass on skills and knowledge to other people.
"We've turned the Great Commission into a spectator sport. Instead, it's more of a military engagement. Everybody has a part to play."