The Fundamentals of Kite Flying

We live in an area where the weather is notoriously unpredictable.  We routinely have rain and sunshine occur simultaneously, blizzards followed by heat waves, and snowstorms in June. 

After becoming a mother, I developed a new appreciation for weather.  I learned that cloudy days are best for blowing bubbles, rainy days are best for baking cookies, and windy days -- which I once loathed -- offer a rare opportunity to learn a few fundamentals of physics.

That being said, here is the essential information you need to fly a kite:

1. You will need a kite (I prefer nylon as they last longer than plastic), kite string, scissors or a pocket knife (to cut out the knots that will inevitably form in your string), and a nice wide open field with no trees or power lines nearby.  If the weather is cold in addition to being windy, you will need a thermos of hot cocoa, a packet of tissues, and hats and gloves.  I actually keep a kite-flying bag in my car just in case the wind picks up.  As I said, our weather is unpredictable...

2. To get your kite into the air, stand with your back to the wind and hold the kite in front of you and as high up as you can.  The goal is to catch the wind in the kite like a sail.   (Although it may be tempting, running with the kite and hoping it will spontaneously take off is usually futile and a little dangerous.)  

3. It is also a good idea to have an explanation of the mechanics of kite flying ready.  Here is how I explained it to my 6-year-old (My 4-year-old still believes kites are kept in the air by magic.): 

a.  Kites are heavier than air, so they need to be "lifted" into the air and held up there by the wind or they fall down. (The weight of the object is heavier than the fluid through which the object will travel.)

b. On windy days, air is blown in one direction very fast. (Lift is a mechanical force which requires both a fluid -- in this case air -- and motion.)

c. If we catch the wind in the kite like a sail, the kite is lifted into the air by the wind. (When the kite is held perpendicularly to the wind, the kite changes the flow of the air, causing the air to flow both above and below the kite.)  

d. Once the kite is in the air, the shape of the kite moves the wind to the underside of it and lifts the kite higher, keeping it in the air.  (The air pressing on the top of the kite is moving faster than the air that is diverted by the kite to the underside, and therefore exerts less pressure on the kite than the air pressing on the underside.  This uneven pressure causes the kite to rise into the air -- a force known as "lift.")

4. Once your kite is airborne, try to keep it at a 45 degree angle to the ground. This is accomplished by letting out and reeling in the kite string. Fly your kite until the wind dies down or the kids lose interest. When you are ready to go, reel in the kite. As it loses altitude, it will lose lift, and fall to the ground.