[Soh"-roh-lahk']

"Leaping Flame"

"Its design has come about over four years of trial and error."

    Meet Sorolach: the paper "airplane" which holds the world indoor distance record. Sorolach is really more like a paper arrow or javelin than an airplane, and that is why it flies so far. Why build a glider when you could have a missile? You have probably seen more than one plane with this same idea behind its design, so what makes Sorolach so different that it holds the world record? The key: get that paper into the nose!!

    One important rule when building any type of aircraft is that more weight in the nose increases stability. In the case of paper airplanes, you have probably seen that adding a paper clip or two to the nose increases the speed at which your plane flies. This extra weight also allows you to throw your plane harder because you have decreased the lift-to-weight ratio. Now you might be thinking, "So if adding a paper clip to the nose makes a paper airplane go farther, why not put a dozen or so of the things on there and hurl it like a baseball?" Well, Guinness must have thought of that too because paper clips or any other weights are forbidden in their rules.

    This is where the trick to Sorolach's success comes in. The only weight to put in the nose is the very paper itself. But, because of another rule stating that "no part of the paper may be cut off and then reattached," the only way to get a lot of paper into the nose was to invent an original folding method. That is exactly what Sorolach is: the embodiment of two years of seeking this new method.

    Great, now that we've got a whole bunch of paper in the nose, what does the rest of the plane look like? Why does Sorolach have virtually no wings? Look back at the first paragraph. Sorolach is a missile, an arrow, not an "airplane." So, naturally, it has extremely high aspect ratio wings (aspect ratio = 2 * (mean chord length) / (wing span)). The wings are really more a sort of paper fletching. But why?? Wouldn't it be even better if the wings were broader? Well, no. When Sorolach is launched, it is thrown like a cross between a baseball and a javelin. It flies so fast that wings any bigger would create too much lift. This would normally be a good thing for a paper airplane, but in this case it is not. You see, Sorolach does not always fly right side up. It is almost rotation symmetric when viewed along its longitudinal axis, and it has to be. This ensures that the same lift vector is generated no matter what the plane's orientation. Wings with a high aspect ratio also help reduce drag at high speeds. More on this later.

Below are some pictures of Sorolach. The plane with which I actually set the record is shown unfolded in the last picture.

Side view of Sorolach. The plane is 21.6 cm long (about 8.5 inches):

Bottom view of Sorolach. Notice the massive amount of paper in the nose (48 layers!):

Back view of Sorolach. Notice the symmetry of the wings and fuselage:

Comparison of Sorolach (left) with my version of Tony Feltch's plane (the previous world record holder). Don't ask why it says "AP Biology Rules!" on the wings of Tony's plane:

The plane that set the world record after the scrutineers unfolded it: