I love airplanes. As you are reading this, you probably have at least a little interest in planes as well. And as any kid will tell you, arguably the best kinds of airplanes are of the "paper" variety. They are simple in construction, cheap in materials, and most importantly, a helluva lot of fun. At least, all the ones I ever enjoyed making and flying as a kid were.
Millions of paper airplane designs exist; every kid seems to know a different one. But by far the best paper airplane I have ever flown was taught to me by my dad, who learned it from his dad when he was a kid in the 60's. In fact, my grandpa invented this design (he was a draftsman, an airplane mechanic in WWII and the Korean War, and holds several patents). So I made this sound like my family's secret paper airplane legacy, but we've taught it to tons of people over the decades so it can hardly be called a secret. Now I'm going to teach it to you.
One more thing: This instructable is an entry in Paper Airplane Contest 3 (https://www.instructables.com/community/Paper-Airplane-Contest-3-Open/). <--- check it out !
Step 1: Materials Needed....
A. Single. Sheet. Of. Paper. 8.5' x 11'.
That's it. This isn't one of those fancy cut-cut-tape-tape-fold-fold paper airplanes; this is pure old-fashioned paper folding.
If you are fanatical about your creases, you could also use the edge of a ruler to run along them, but your fingers should do well enough for most people.
Step 2: Construction - Step 1
Placing your paper vertically (portrait view), first fold your paper in half vertically.
Step 3: Construction - Step 2
Unfold the paper. This leaves a reference crease down the center, which I have marked in red.
Step 4: Construction - Step 3
Fold the upper right corner down 45 degrees, until it exactly touches the reference crease. [Pic. 1]
Repeat with the upper left corner. [Pic. 2]
Everything should be lined up as close to perfectly as possible. Exactness counts.
Step 5: Construction - Step 4
Fold the point made by the last two folds straight down, forming a tight triangle.
Step 6: Construction - Step 5
Take the upper right corner of triangle, and fold it down to touch the center line, but touching it a half inch above the lower point of the triangle [Pic. 1 for clarification]. This will leave a half inch along the top as well, which we want [Pic. 1].
Repeat the last fold in reverse with the upper left corner. A downward pointing triangle should be visible below the points of the last two folds [Pic. 2].
Take this triangle, and fold it straight upward, over the touching points of the last two folds [Pic. 3]
Step 7: Construction - Step 6
Fold the plane in half along the reference crease, such that the small triangle is facing outward. The small triangle is now holding the plane together. [Pic. 1]
Fold the first wing down [Pic. 2]. It should be slightly at an angle from the keel of the plane body (the part formed by the reference crease), tapering toward the front of the plane. A good rule of thumb is that the keel should be a quarter inch tall at the snub nose, and 3/4's of an inch at the tail. I know this sounds confusing, just look at the fold marked in red in Pic. 3 and hopefully what I mean will be clear [Pic. 3].
Make an identical fold on the other side to make the other wing [Pic. 4].
Step 8: Construction - Finished
The snub nosed little plane is now finished. It should look like this [Pics. 1 & 2].
Now you can experiment with flying this resilient little guy, or you can continue reading this instructable to garner a few hints about achieving stable flight, a loop-de-loop, and a wingover maneuver (all requirements for the Paper Plane contest 3).
Step 9: Flying - Stable Flight
This little plane, if made correctly, is naturally incredibly stable. To make it so, make sure the wings are angled up as to make a very slight "Y" when viewed from behind, maybe 10 degrees above the horizontal. You don't want a "T" shape, or even worse a "/|\" shape. [Pic. 1]
To throw it, use a standard paper airplane grip (I don't know how to explain it any simpler than that :-) [Pic. 2] and give it a gentle, level, throw.
Step 10: Flying - Loop-de-loop and Wingover
Because this is such a stable (and nose-heavy) plane, making it perform tricks takes a bit of doin'.
First I fold a set of flaps in series on both wings that are set at two angles (one shallow, one steeper) to get that nose up [Pic. 1]. Getting the angles of the flaps just right can take a few trys, so to aid you I've taken a picture to help show the angles that worked for me [Pic. 2]. With the flaps shown in profile it appears that the first (wider) flap is angled at 5-10 degrees, and the second (narrower) flap is angled 10-20 degrees from that, for a total of 15-30 degrees across both folds.
Secondly I put a medium-small paperclip about 2/3rds back on the plane body, to help balance out the heavy nose and allow for faster and better maneuvering [Pic. 2].
Loop-de-loop: For the loop, make the above mentioned folds, then grab the plane how you would normally and make a level throw as you would for straight flight, but with just slightly more force (gotta force that nose up). With proper force, planes made on heavy paper will achieve small loops and planes on lighter paper will achieve medium loops.
Wingover: I was surprised to find this out (I'd never tried a wingover before this contest) but to achieve a wingover with this plane you don't need to make any physical changes to the design or flaps from what you did to achieve the loop. Keep everything exactly as you did for the loop. To do a wingover, you just have to throw it differently. Instead of holding the plane upright (so the wings make a "Y" when viewed from behind), cock it slightly to the left such that the left wing is parallel with the floor (horizontal). Now throw the cocked plane straight ahead, level with the floor, and instead of performing a loop it will pull up and to the left until it stalls, turns around, dives, and then pulls out facing 180 degrees the other direction - the perfect wingover.
Hopefully this simple plane provides a bit of fun for some kid somewhere, just as it has for me over the years. And who knows, maybe it will win a contest for me too :-)