You start off having the kids make paper air planes, writing their names on them and giving them a throw. Then you measure distance traveled (by number of floor tiles) and they record their data, and make one change to the design. At this point I have the students write a hypothesis, they write it on their plane and follow my template. Then we throw again, record data and talk about independent variables, dependent variables and controls. I talk about repeated trials. I also talk about control groups (but its not in the ppt). We write a conclusion and talk about the hypothesis being supported or not supported The students write all their information for the class on their plane and turn them in at the end of class.
You can even talk about peer-review for those students who would like a tutorial from a classmate whose airplane is getting better results. This is also a great time to talk about the difference between cheating and getting help. If a friend is making a plane for you or giving you their plane, that is cheating. If a friend is teaching you how to make a plane without touching your paper, that is a tutorial.
So why are there post-its all over the back of my room? Because, I tell students that if they can make it past the back grey line in my room, they can put their name on a post it, and brag to their friends. Everything is better if it's a competition. If the planes slide on the floor, I count it.
I am not nice enough to take the kids out in the hall for this activity (though you can probably get bonus points from your principals if you do). If the students complain about the planes hitting tables or other obstacles, I explain that life is full of obstacles and we have to learn to work around them and to keep trying after we hit obstacles.
It is also important to note that I send an email to all the teachers in my building letting them know that my students have been making paper airplanes and have been told not to make or throw paper airplanes in other classes, or they will get in trouble. And I tell the kids that their teachers know they are not supposed to be making paper airplanes in other classes. Not that I don't trust teenagers, but ...