There are better materials to use for airplane construction than concrete. But that didn't stop a team of student engineers from creating the first successful aircraft made out of material normally used to build things that stay on the ground.
A three-student team at South Dakota School of Mines & Technology designed, built and flew the 18-pound model plane about 20 feet last month. Using an infamously heavy material to fly through the sky presented plenty of challenges, according to Seth Adams, who worked on the project with David Haberman and Tyler Pojanowski for a year.
"With the plane being that heavy, you need to create an air foil that has a lot more surface area than you'd normally need for one made out of plastic or another lighter material," he says. "We made the wings hollow by sticking foam inserts inside it to reduce the weight."
Other concrete planes have been made before, but the South Dakota team's version was the first to take off and land without crashing. The plane was powered with a gas engine and a two-prop propeller. Adams says the plane flew at a height of about seven feet before it landed. The plane suffered some minor cracks, but he says it could easily be repaired to fly again.
The team plans to leave the plane for next year's students, who they hope will improve on the design.
"A tough thing with concrete is it's hard to put the center of gravity exactly where you want it," he says, which caused the plane to wobble as it flew.
As you might expect, there's not much of a future in the concrete aviation industry.
"This was just a fun engineering challenge. I don't think concrete as a material would be good to use for commercial airplanes," Adams says. "It's very brittle, it's heavy and it's terrible in tension."