'plane-driven' to create roadable aircraft
By Dana Heimos
Johnson, of Seattle, Washington, says the inspiration for his roadable
Glasair Sportsman came to him as a child when he saw Molt Taylor's
Aerocar at the Smithsonian National Air and Space Museum. "I
enjoyed all of the airplanes, but I kept coming back to that one,"
Years later, after building an RV-7 and
flying many hours in amphibians, Trey built a Sportsman GS-2 in Glasair
Aviation's Two Weeks to Taxi program earlier this year and he added a
unique innovation: a ground-side drive system that allows him to
"drive" his airplane between airports.
How is this accomplished? A pod system
located on the belly of his craft houses the power and electrical
components that transition the airplane for ground movement.
The pod and rear wheels slide back via a
railing system to help shift the center of gravity, and the wings fold
backward to create a more compact design.
The result? A street-legal, highly
maneuverable airplane capable of both cross-country flying and keeping
up with road traffic.
"My primary design goal was to avoid
introducing any new points of failure," Trey said. "This was
accomplished by using two separate engines and electrical systems-one
for flying and one for driving."
Trey says another goal of his was to keep
the added weight and drag comparable to that of a plane on floats.
Although the gas mileage suffers a little and its max speed is only 118
mph, Trey says he's happy with the results and plans to work on
improving the performance now that the system is fully functional.
"I wanted to keep everything as
normal as possible for the pilot, and everything as normal as possible
for the driver," Trey said. "The pilot still has a stick, toe
brakes, and conventional rudders. And the driver has a central brake,
automatic transmission, reversing abilities, and a steering wheel."
Trey flew his roadable Sportsman, N390PD,
into Oshkosh Wednesday afternoon after trailering it from Seattle,
Washington, to the east side of the Rocky Mountains.
He plans to stay for the rest of the
week. Look for it next to the Homebuilder's Hangar.