Paper Airplane Aerodynamics: Comparing 3 Designs
Objective
Compare flight performance across designs and identify which design variables most affect distance, stability, and trajectory.
Design
Controlled variables
- Same paper size
- Folding precision status
- Test location, environment (wind, pressure, temp, etc.)
- Launch height & force & Method (by hand)
Independent variables
- Plane design
Dependent variables
- Distance (cm)
- Drift direction (PYR)
Do
I followed every single step in the instructions and had no issue.
#3 Plane
87851770646908_.pic.jpg Plane #3 — the dart-style design after folding
The folding process is very simple: I just fold the top 2 corners to the center, make sure the top edges touch the middle line, then do that again. Then fold the middle line and finally fold the flat surface. It flies well since there’s a minimal drag profile. As I throw it stronger, it flies farther. It also depends on the angle I throw, an angle from 0 to 30 is optimal. A larger angle would cause it to change its angle too early and head straight towards the floor.
#4 Plane
87841770646907_.pic.jpg Plane #4 — the bulky front-loaded design
It sucks, as it always yaws and does not fly far. It was because there was a huge frontal area that blocked the airflow on the plane.
#6 Plane
87861770646909_.pic.jpg Plane #6 — the wide-wing design
This plane works a lot better than #4, but still not the most optimal one. It usually flies flat at first, but then pitches up and hits the ceiling.
According to aerodynamics, it might be because the center of gravity is at the back of the plane. There’s no significant up-elevator appearing on this plane, so that is the only reason.
It might also be because someone made this paper wrinkly, so it flies badly.
Comparison
WechatIMG8797.jpg Flight test setup for all three planes
WechatIMG8798.jpg Flight path results marked on the floor
I have done a test flight for each of them.
#4 Plane did the worst as predicted, the results of the rest of them are pretty close. They all fly over 5 meters. The problem is that both planes’ tracks got curved during the flight.
Result
| Plane No. | Distance (cm) | Drift Direction |
|---|---|---|
| 3 | 583 | Yaw right |
| 4 | 115 | Massive rotation |
| 6 | 514 | Pitch up |
Aerodynamics
#3 Yaw
I suspect yaw is primarily caused by fold asymmetry, because the rest of the parts of the plane looks perfect aligning with aerodynamic considerations. Even small differences create a drag imbalance that matters during flight.
#6 Pitch
The pitch-up behavior suggests the plane is tail-heavy or has an effective up-elevator due to wing curvature. This causes the head to rise and the plane to climb abruptly before stalling.
#4
This thing is awful, so I ignored it in later analysis.
Diagnose
I checked #4 and found that the original printing of the folding guide lines were already misaligned.
Conclusion
Across all 3 test flights, #4 performed worst as predicted: after I launched it, it was like hitting an obstacle and suddenly stalled. #3 and #6 both exceeded ~5 meters, but neither was perfectly stable. Both showed curved trajectories, suggesting they have either minor folding asymmetries or trim imbalances. Another reason might be that #6’s wings are larger and catch more wind, which generates an upward force from it. #3 does not have this problem because the wings are thin and close to the center of mass.
Extension
Because of the Gimbal Lock, people usually use Quaternions to record YPR instead.
This post is part of an aerospace engineering course project comparing paper airplane designs under controlled conditions.