Have each student design his own plane, based on drawings or photos found in books, websites and other media. Have the students launch the airplanes across the room. Measure how far each airplane flew. From the results, extrapolate which airplane was the best and why.
Create groups of five students each. Have the groups work together on a paper airplane design. Just like with the individual design experiment, have each group launch the airplanes across a room. Measure the distance of each flight. Ask the students to go back into their groups and figure out why one design was better than another.
Have the students bring in old newspapers, cardboard boxes and construction paper, then have each student design and construct different paper airplanes from each material. Have the students posit which material will be the most and least aerodynamic, and why. Launch the airplanes. Measure the distance the airplanes traveled. Discuss the results as a class or in groups.
Make five different paper airplane designs. Ask students which kind of airplane they think will fly the farthest from a third-story window. Ask how the wind and gravity will influence the airplane's flight trajectory. Launch the airplanes and measure the flights, then discuss the results. Be sure to get permission from your supervisor before trying this experiment.