Bio-aerial Locomotion 2011

In 1971 Paul MacCready founded AeroVironment, Inc.. Considered the father of human powered flight, MacCready went on to invent flying devices with his company ranging in everything from solar powered flight to the Gossamer Condor, which flew over the 23-mile long English Channel off of only the power of an onboard cyclist.

And as the saying goes: like father, like son.

When Paul MacCready’s son, Tyler MacCready, was only about 13 years old, he already had developed a livelong passion for flight. When he wasn’t helping his father work on the Gossamer Condor he and his older brother were competing to see who could make a better paper glider. Through their competition they realized that by moving their hands underneath the glider they could drastically affect its flight.

From there Tyler and his brother went on to experiment with their toy invention and attempt to find which models would work the best. Their father, of course, played a major role in helping them understand the mechanics of flight and how they could increase the performance of the glider.

Tyler MacCready demonstrating his invention.

So how does it work?

Despite the amazing simplicity of its design, the Walkalong Glider is actually quite complex.

As quoted from his appearance on his fathers TEDTALK: “The idea is that it soars on the lift over your body like a seagull soaring on a cliff. As the wind comes up, it has to go over the cliff. As you walk through the air, it [the air] goes around your body, but some has to come over you, so you just keep the glider positioned in that up current. You can turn it left or right by putting the lift under one wing or another.”

To elaborate, MacCready is controlling both the pitch and the roll axes of the glider by the placement of his hands underneath the wings. In the case of a roll turn, that is achieved by varying which wing is experiencing more updraft from your hands. In this scenario, to turn left, one would have their hands slightly more on the right wing. The glider would then perform a banked turn. This is pictured below:

In the case where we are looking to change the pitch of the glider, that involves the movement of our hands forward and backwards. Moving forward will put more lift on the front of the glider thus increasing the angle of attack. This process is pictured below:

But be careful!

If you increase the angle of attack too much, then the glider will experience stall and come crashing down.

Since its discovery there have been many variations of the Walkalong Glider. The most simple and functional one that I was able to find is called the tumblewing. For information and instructions on how to make your own tumblewing glider please click here.

Sources:

1. Walkalong Glider History

2. Paul MacCready Biography

3. Walkalong Glider with Tyler MacCready

4. How to Fly a Walkalong Glider

5. Introduction to the Tumblewing