Egg Glider

A high school physics project back in 2003 required the following:

Transport an uncooked egg from the top of a 60 ft building to the ground below as far from the building as possible without breaking it, without using off-the-shelf components. There were also dimensional and weight limits imposed (I believe the device had to fit in a 1 m x 1 m x 1 m box, and weigh no more than 2 lbs). There were a multitude of different designs created, most seemed to focus either on providing an as gentle descent as possible, or on proving the maximum amount of initial velocity away from the building, with control of the rate of descent as a secondary priority (usually resulting in the construction of some sort of container in which the egg was tightly constrained and heavily padded).

I took the approach of building a glider in which the egg functioned as the nose weight. The glider's forward body was constructed out of shaped Styrofoam on a balsa wood frame, with a pocket to fit the egg snugly as if it were the pilot. Since there was to be no interference with the object during its descent, the option of remote control was not available. This meant that the aircraft had to be inherently very directionally stable if it was to avoid circling back and landing at the base of the building. For this reason, a significant amount of wing dihedral was incorporated into the design. The wing, horizontal and vertical stabilizers were constructed from a balsa wood frame, with RC aircraft wing covering film providing the aerodynamic surface. Because of the restriction on control, the only control surface was a manually adjustable horizontal stabilizer, the required pitch of which was determined through numerous test flights.

The day the competition took place there was a bit of a breeze causing a strong updraft in front of the building. This made it mandatory to release the glider at an airspeed greater than the airspeed it would settle into in a glide. After a few pitch up and stall oscillations (which drastically reduced its glide slope form ~15:1 (which it demonstrated on numerous test flights) to ~2:1 the glider landed over 100 ft from the building, with the egg intact!

The glider was later upgraded with a fiberglass forward fuselage to protect it better from hard-impact landings. Here are some pictures of test flights some time after the competition; I unfortunately do not have any pictures from the competition as this was before the day that everybody carried a digital camera in their pocket.