How to Design Your Own Paper Airplane (Ep.1) — The Four Major Forces
Updated: Feb 10, 2019
So you’re tired of folding everyone else’s paper airplanes and you want to design your own, but you’re not sure how to begin. Perfect! This post was written just for you. I cover the topic in the video above, but I'll give you a nice summary below!
In order to design our own paper airplanes, we'll want to first examine some existing designs and see if we can figure out what makes them successful. Let’s begin by considering the four major forces that act on any plane. We have Thrust — that’s what makes a plane go forward, Drag — that’s what slows a plane down, Gravity — which pulls the plane back to the earth, and Lift — which keeps the plane aloft. To create a successful paper airplane design, you should maximize Thrust and Lift, and minimize Drag. It would also help to minimize gravity, but we can’t easily do that without leaving the planet. So we’ll assume that gravity remains the same for each paper airplane.
SO HOW DO WE MAXIMIZE LIFT AND MINIMIZE DRAG?
On real airplanes, thrust is created by turbines and can continue to be created during the course of flight. But all of a paper airplane’s thrust comes from the initial throw. So in order to maximize the amount of thrust your paper airplane can achieve, it needs to be constructed in such a way that it can be thrown quite hard. Planes that can withstand a high launch velocity will fly farthest or for the longest amount of time.
In order for a paper airplane to survive hard throws, its wings must have strong leading edges. You can see in the image below, I’ve folded several of my planes out of a transparent vellum. Though the construction of each plane is dramatically different, each of them has the highest concentration of layers on the front edge of its wings. This helps the wing hold its shape at high speeds, and maximizes its potential thrust.
It’s no secret that it’s the wings of your paper airplane that are generating it’s lift. So you should just make the wings as big as possible, right? Well, yes! And still somehow no. This is one of the balancing acts of designing a paper airplane. The longer you make the wings of your airplane, the less paper you have left to fold strong leading edges, therefore requiring a softer throw and reducing your plane’s thrust potential. It’s also likely to stall if the center of gravity isn’t far enough forward. And the wider you make the wings of your plane, the more they’ll want to bend, even in spite of their strong leading edges — again reducing it’s thrust potential.
The balancing act continues when you consider the angle of your wings. Wings that are flat produce the most lift, and are often employed on planes that are designed to fly for long amounts of time. But if you angle the wings slightly upward, your plane will gain directional stability at the expense of some lift. This is called dihedral angle and is employed on many distance models. Angling the wings downward sacrifices both lift and directional stability and is only used in a few specific scenarios — like if you’re trying to get a plane to fly back to you.
So you can see that, while it would be nice to be able to fold huge wings and maximize lift, there are some other design challenges to take into consideration. And while maximizing lift is a good goal in theory, a more realistic goal is to try and achieve the most lift possible without compromising the plane’s structural integrity or — if you want it to fly far — the plane’s directional stability. It’s good to experiment with different wing sizes and angles for any given design to try and find the best balance for the performance you’re hoping to achieve.
HOW DO WE MINIMIZE DRAG?
As your paper airplane moves forward, it has to push air molecules out of its way. The less air your plane has to move, the less drag it will encounter. There are many ways to reduce drag on a paper airplane, but the most important one is to fold your plane in such a way that it has as few forward-facing pockets as possible. These pockets catch air as the plane moves forward and will dramatically decrease its performance. This is a rule I sometimes break for the sake of aesthetics, but it always comes at a cost.
Let’s recap the things we’ve discussed in this post. If you’re hoping to design a high performance paper airplane, there are three major goals you should aim for:
1. Maximize Thrust
You achieve this by folding strong wings with many layers on their leading edges so you can throw the plane hard.
2. Maximize Lift without sacrificing too much in other areas
This is a balancing act in which you try to find the right wing size and angle without
compromising wing strength or directional stability.
3. Minimize Drag
While there are additional ways to achieve this (that I may discuss in future videos) the
fundamental rule here is to fold a plane without any forward facing pockets.
And there you go! Armed with those principals, you now know generally what it takes to make a good paper airplane. Get out there and get folding!