History is full of engineers making (or attempting to make) things out of the wrong stuff, from massive wooden aircraft to boats made of ice and sawdust. [PeterSripol] is attempting to make an ultralight aircraft out of a rather wrong material: cardboard. In the previous installment of the project, a pair of wings was fabricated. In this installment, the wings find their home on an equally mostly cardboard fuselage, complete with rudder and elevator. 

The fuselage construction amounts to little more than a cardboard box in the shape of an RC airplane. Doublers provide additional strength in critical areas, and fillets provide a modicum of additional strength around seams. To support the weight of the pilot, a piece of corrugated cardboard is corrugated again, with an additional piece making up the floor. With the addition of a couple of side windows for comfort and visibility, the fuselage is completed, but additional components need to be added.

The most difficult challenge in making the fuselage is, in part, unrelated to the building material of choice. To allow the aircraft to be transported to the show after it’s built, the wings are detachable. Detachable wings would be no big deal on a normally constructed ultralight, and permanently affixed wings would be no big deal on a cardboard aircraft, but the combination of the two poses structural integrity challenges. As such, some plywood and aluminum are used to provide the strength needed.

The horizontal and vertical stabilizer construction is fairly simple, with cardboard folded over ribs creating a rather strong surface. At the ends of each are mounted the elevator and rudder, with fiberglass tape making up the hinge. Finally, the tail is mounted to the airframe using a couple of wood screws and some rope.

Despite the questionable choice in materials, the aircraft appears to be reasonably strong, and we love seeing things used in ways they were never intended. Make sure to stay tuned for more coverage, and while you wait, read our write-up on the previous installment of the project!