Concrete: construction material of the future?

Jul 03, 2013 18 Comments by

South Dakota School of Mines & Technology students David Haberman and Tyler Pojanowski  were the first to fly and safely land an 18-pound RC concrete aircraft. The flight was quick and wobbly with the landing equally erratic, but it was enough for the record books. The 18-pound plane held its own during a crash landing to become the second known concrete plane to fly and the only one to stay intact upon landing.

The only other concrete airplane known to have flown was designed at the prestigious Embry-Riddle Aeronautical University in Daytona Beach, Fla. That plane crashed and was destroyed, according to Mines advisor, M.R. Hansen, Ph.D., an expert in concrete design. “My friend, Dr. Mark Fugler, concrete advisor at ERAU, was my inspiration to try this project. Their concrete airplane did fly first and proved that it could be done. Our goal was to do that and have it land safely.”

Mission accomplished: “Ours flew and sustained some damage on landing but was not destroyed. So, you could say this is the first concrete airplane to fly and land,” said Hansen, who notified Embry-Riddle of the School of Mines’ milestone.

The plane, with a wingspan of 40 inches, was designed and built entirely by three SDSM&T seniors who recently graduated. David Haberman and Tyler Pojanowski, both mechanical engineering majors, and Seth Adams, a civil and environmental engineering major, worked on the plane for a year as part of their senior design project. Hansen and Lidvin Kjerengtroen, Ph.D., advised them throughout. The group had just one shot to test a year’s worth of work.

Watching the concrete plane taxi 200 feet along the runway at the Central States Fairgrounds was a bit unnerving, said Pojanowski. “I was really nervous. We put a lot of time into it to see if it would work or not, and once it took flight I was shocked. The numbers said it would fly, but numbers and actually seeing it fly are two different things. Seeing it was exciting and proved that what we did during the semester was true,” Pojanowski said.

Haberman produced calculations to determine the take-off and lift distances, and what he projected is what they saw. The main goal was for the plane to take flight and to survive the landing. Once the wheels were off the ground it was over in a matter of mere seconds, thanks to weight-balance issues associated with flying any plane. “There wasn’t much time because once it got air it just went over, it flipped over. I was freaked because I was really close to it and was worried it was going to hit me,” Pojanowski said.

Though made with carbon fiber reinforcement, it is concrete, after all, and a bold, yet fragile design to attempt to fly. And once it comes crashing down it would not be unreasonable to expect disintegration. In fact, that was Haberman’s initial thoughts when he saw a cloud of dust. “I was initially kind of disappointed because I saw a puff of smoke and thought it had exploded. I was excited to see it all in one piece. I think the smoke was some of the concrete kind of grounded against the asphalt,” explained Haberman, who was operating the remote control.

The plane sustained a crack in the fuselage and wing but otherwise remained intact, thanks in part to the students’ design plans and decision to reinforce the concrete to a safety factor of two, which meant it was twice as strong as it needed to be: strong without being too heavy. Adams, one of Hansen’s students, used the same concrete mixture that went into the university’s award-winning concrete canoe. It’s a light mixture with extra carbon fiber reinforcement.

“Everything in aviation you want to be high strength and low weight, and concrete is the exact opposite. That’s why the professors did the project, to challenge engineers, to see what we could do. The thing I’m most proud of is … we did it with two MEs (mechanical engineers) and one civil (engineer),” Haberman said, pointing out their success was accomplished with a small team. The issues with the plane flipping on its back while in flight weren’t completely unexpected. Learning to balance a remote-controlled plane while in flight is tricky and requires practice, a unique problem for students who hoped for a smooth landing so they could display their concrete airplane afterward at the Senior Design Fair.

“There is a lot more to aerodynamics and landing a plane than people realize. Even a regular remote-controlled plane of this size, which would normally weigh 4 to 5 pounds, those are hard to get up in the air and land,” Haberman said. “Landing wasn’t as big of a priority. The goal wasn’t so much to get it to land or even fly it around that much. It was more to get it up in the air and to prove that we could fly it and get it off the ground.” Which they certainly did.

“We could’ve tried to fly this one again just to prove it flew again and to try and see if we could land it more softly, but we just wanted to leave something to the school to show what we did, and leave it in one piece,” said Haberman, adding that the history-making concrete airplane will hang on display in the SDSM&T’s Center for Advanced Manufacturing and Production laboratory. Hansen is already looking ahead to the next challenge. “Phase III, hopefully next year, will add servo-controlled ailerons to control turning and help with a smooth landing,” he said.

 

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Debra Cleghorn, Featured News

About the author

Executive editor About me: I’m a publishing professional who has a passion for aviation and RC, and I love creating issues, books and a website that help RC pilots to enjoy this sport even more. I admire scale aircraft and enjoy the convenience of flying smaller electrics.

18 Responses to “Concrete: construction material of the future?”

  1. J says:

    Has the propeller been instralled inverted ?

  2. Gary says:

    Great job guys. Like I’ve heard tell…….put a big enough motor on it and you can fly anything!

  3. Ken says:

    The large gaps between the vertical stab/rudder & horizontal stab /elevator seem like a recipe for disaster (inducing flutter). Perhaps they contributed to the very short flight time?

  4. Pete Cook says:

    Some dyhedral in the wing would make a huge difference.

  5. Andrew says:

    As a civil engineer and avid RC enthusiast, I applaud the use of “alternative” materials for model aircraft construction. A unique (if somewhat short lived) effort. Well done!

    Next effort: an ice plane, MythBusters style!

  6. teckbot says:

    Is there a video link? It would be neat to see

  7. Jim London says:

    Sorry fellows. Telling the world your plane flew is like telling the world you or anybody else did that jumped of a curb. Getting the wheels off the ground and immediately going inverted and crash landing is not flying.
    You can ask a commercial plane load of pilots and passengers if that is flying over the intercom as your taxing that aircraft down the run way.
    What was accomplished was a good taxi, not much more.

  8. weinig says:

    Not much of a flight, it does go airborne for a second, but I wouldn’t call that controlled flight.Nice try though.

  9. Hiapo says:

    Interesting concept in material selection! With enough power, even a rock will fly, won’t it?

  10. RR says:

    I don’t buy the excuses. Hundreds of RC pilots fly New airplanes of varying design size and weight successfully every day. It is NOT that hard to make a successful first flight, nor to trim the airplane while in flight. To say that is taking away from people who do it all the time.
    Why didn’t they get an experienced RC pilot to fly it the first time? I agree with the other poster, Wheels off ground, flipping inverted and crashing is NOT flying.

  11. Glen Dobbs says:

    The dihedral would be a good improvement, ailerons, a rudder and horizontal stabilizer. Wondering if you used a foam core for the wing or if it was solid. You could probably make a very thin skin of concrete if you use a core material. Keep it up – fun stuff!

  12. CMunsk says:

    I wonder if they balanced the plane??? Wish they would’ve got and experienced pilot to fly it and added a dihedral; then it could’ve been legit

  13. Al Ward says:

    Well even the Spruce Goose “flew” did’nt it but with more stability..If they’d had a longer wing with polyhedral or dihedral it would have lasted much longer like the old payloader models….

  14. Herman Burton says:

    As a registered professional (civil) engineer for nearly 50 years, I have designed and had constructed many different concrete structures. Close to Galveston are two concrete ships, commissioned during World War II, but both sank on their maiden voyages out to the Gulf of Mexico. But a concrete airplane? I bet those young men had a lot of fun designing and building their model – and I hope they install ailerons next time for some slight amount of control.
    What a hoot! Great story! Great achievement!

  15. allan davis says:

    A lot of up elevator got it airborn….but that aint flying!

  16. Aaron Scott says:

    Committing to a fly or die scenario on the first run is unrealistic, even tried and proven airframes need adjustment before the first flight.

  17. John Spoonamore says:

    Eighteen pounds, 40-inch wingspan, OS 2-cycle engine, . . . .size (cc’s)????
    Nice article. Thanks.

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