Back in the late 1980's and early 1990's, I did a lot of classroom volunteer work, in the guise of "Mr. Engineer". I visited public and private schools and did a thing about airplanes.

I fabricated 3 or 4 different wind tunnels to "test" paper airplanes; we would put the planes in the tunnels and see how many paper clips they could lift in a cup hanging under the planes. They learned the importance of wing area, curvature and wind velocity.

I had a set of pre-designed cutouts of my own; and I also let the kids make their own designs after the technical experiments were out of the way.

It was a lot of wok but I enjoyed it enormously, and so did the kids, and of course the teachers welcomed a break from their daily schedules.

Just as we were closing out my last year of windtunneling, one of the retired GE engineers gifted me his own homebuilt design. I never had the heart to tell him the party was over. I still have this up in the garage attic, along with my own.