Here are the steps needed in order to make a basic dart design of an airplane, this one is one of the more simpler ways to create a functioning airplane. The design even appears as far back as 1882 in the 1882 edition of Cassell's Book of Sports and Pastimes. This shows how iconic and simple the design can really be, and how easy it can cause mischief as well as the book has it as a subject. These back then used to be called "paper kites" and "paper darts".
Step One:
You first want to fold the piece of paper in half, something like the coveted hot-dog design. You simply do this by grabbing the top of the paper while it's horizontal and folding it down to the bottom. I usually try to line up the top with the bottom before I begin adding creases to the piece of paper. After that step you're gonna wanna unfold the paper as well. It should end up looking like the picture provided.
Step Two:
Secondly, you want to fold the corners of each side into the middle, or where the crevice is. I usually try lining up the edge of that corner into the crease, which allows it to look like the image provided.
Step Three:
Now that your paper is creased the way it should be, you want to keep it creased like that because it's important to the next step of this process. This step allows you to take the top edges, and lets you fold it into the center, making it look like the picture provided.
Step Four:
Secondly, you want to fold the corners of each side into the middle, or where the crevice is. I usually try lining up the edge of that corner into the crease, which allows it to look like the image provided.
Step Five:
For the last and final step, you're going to want to fold the top of the end to the bottom of it, where it should now then represent a basic dart paper airplane. After that you should be done, and your final product should look similar, if not exact, to the picture provided.
Sources Used:
Did people fly paper airplanes before real airplanes were invented? - Vox