Project: Wing Loading

Background:

Wing Loading is the measurement of how much weight each square unit of the lifting surface is required to support in flight. Usually, commercial and general aviation aircraft are designed to fly at a particular speed and wing size to in order to lift a maximum cargo weight. Computation of wing loading is needed to properly size: wings, power requirements, runways, and support structures within the aircraft. The question arises for unpowered aircraft, is wing loading an important factor in determining flight speed?

Hypothesis:

Since paper airplanes are unpowered aircraft, the area of the wing will be a major factor in determining average flying speed.

Experiment Design:

Three paper airplanes with a range of wing sizes will be folded with 8.5 x 11 inch graph paper. Square units will be counted to determine the wing areas of the aircraft.

The precise wing loading of each plane will be determined by dividing the number of square units by the weight of the paper. Computation of the weight of the paper will be performed using the following paper manufacturing standards. 20 pound paper means 500 sheets of 17 inch x 22 inch paper weighs 20 pounds. Each sheet of this large paper can be cut into four sheets of letter size (8.5 x 11 inches). 20 divided by 4 is 5. So, a standard 500 sheet ream of 20lb paper weighs 5 pounds. Therefore, 100 sheets weighs 1 lb. And a single sheet weighs .16 ounces (16 ounces to a pound). That converts to 4.53592 grams.

Similar calculations will be performed for 24 and 26 lb paper to determine the weights of single sheets.

Analysis of wing loading effects will be analyzed in two ways. First, by comparing the same aircraft design using different weights of paper, and second by using aircraft, with varying wing sizes, folded with the same paper weight.

Average flight speed will be determined by using a video recording device and frame accurate edit software. Flights will be recorded over a 3 meter distance near the end of the glide path, so that initial thrust supplied by the thrower will be used up. The goal is to capture that part of the flight where the aircraft is trading height for speed at a stable glide. Video frames will be counted from the time the plane crosses the beginning marker until the plane crosses the 3 meter marker.

Care will be taken to determine the frame rate of the video. 30 frames per second is the standard for interlaced video and some progressive video is recorded at 60 frames per second.

By counting the total number of elapsed frames and dividing by 30 (or 60) the precise number of seconds the plane takes to fly 3 meters can be determined.

Care will be taken to adjust the planes so that the glide patterns are stable; neither "porpoising" or diving.

10 trials with each design and paper weight will be performed and recorded. Data will be collected and analyzed.

A comparative analysis of wing size and flight speed will be performed. Also a comparative analysis of aircraft weight and flight speed will be performed. Charting two variables related to the specific components of wing loading may make the relationship clear with regard to airspeed.