Hands on · companion to the design studio
The paper glider test
The Wrights did not trust a number until they had measured it. Here you build two gliders, change one thing, and measure what that change does. Then compare with what the design studio predicts.
You need
- Four sheets of ordinary paper (letter or A4).
- A tape measure or a floor with tiles you can count.
- A step or chair to launch from, so every glider starts at the same height. About 1 meter (3 feet) is good.
- This sheet and a pencil.
Build the control glider
- Step 1. Fold the sheet in half the long way, then open it.
- Step 2. Fold the two top corners to the center line.
- Step 3. Fold the new top edges to the center line again, making a long point.
- Step 4. Fold in half along the center line so the point is on the outside.
- Step 5. Fold each wing down to meet the bottom edge. Open the wings level.
Build the test glider: change one thing
Make a second glider exactly the same way, then change only one of these:
- Wing area. Trim 2 cm off the back edge of both wings. (Less wing: the studio's "chord" slider.)
- Camber. Curl the back edge of both wings gently upward over a pencil. (The studio's "curve of the wing.")
- Weight. Add one paper clip to the nose. (The studio's "pilot" and "engine" weight.)
Measure
- Stand on the step. Hold the glider at shoulder height, level, and let it go with a gentle push. Do not throw it hard: a glider should glide, not fly like a dart.
- Measure the distance from directly below your hand to where the nose first touched the floor.
- Do it five times for each glider and write the numbers down. Cross out any throw that was clearly different from the others.
- Measure your launch height once.
| Throw 1 | Throw 2 | Throw 3 | Throw 4 | Throw 5 | Average | |
|---|---|---|---|---|---|---|
| Control glider | ||||||
| Test glider (changed: ________) |
Launch height: ________
Work it out
Glide ratio = average distance ÷ launch height. A glider that goes 6 meters from a 1-meter launch has a glide ratio of 6: it travels 6 forward for every 1 down. That number is, roughly, lift divided by drag.
Now open the design studio, choose "No engine," and read "Lift ÷ drag." Full-size 1903 gliders reach about 8 in the model. Paper gliders usually get 3 to 6. Why might a paper glider do worse than the model? (Think about how smooth the paper is, how thin the wing is, and how steady your launch was.)
Talk it over
- Did your change make the glide longer or shorter? Did every throw agree?
- The Wrights took hundreds of glides in 1902 before they trusted their numbers. How many throws would you want before you were sure?
- What would you change next, and what do you predict will happen?
From airand.space, a free history of flight. Independent and not affiliated with the Smithsonian Institution or the Wright family. Print freely for classroom use.