Wind Shear, Sheer Panic
(Foster City, CA, USA)
For years, I had begged for a "kite with cartoon characters on it" (aka a retail kite), and finally, for my 10th birthday, I got a box kite with the "Garfield" characters on the panel. The kite was about 3 feet tall, just about a foot shorter than I was, wind-rated 5-20 mph, and recommended to be used with 50 lb test line. The strength of the line alone should have been a big clue about how much resistance that kite would have once up in the air.
I lived on a cul-de-sac with no trees, and we used to fly our kites in the street. The wind was blowing about 9 mph, so I had no problem getting the kite up in the air. I loved how spectacular it looked while airborne; it reminded me of an old, World War I era bi-plane. The sight must have distracted me, because I kept letting out more and more line, not realizing that the kite was getting up into the higher elevations, and higher wind levels.
The higher the kite went, the harder it became to control, and I began to realize why 50 pound test line was recommended. The kite began to tug hard, and I felt my feet get dragged a little over the pavement; it was now putting out slightly less resistance than my own body weight, and it seemed that the more I tried to reel the kite in, the more it resisted.
Finally, in an act of desperation, I threw myself sideways onto the pavement and pulled with all my might and weight. This was my big mistake--apparently, my pulling to the side altered the airflow over the surface of the kite, and it now had zero lift. I watched in horror as the kite plummeted straight to the ground at what seemed to be terminal velocity (obviously not, but to a 10 year old, it certainly looked like it). The kite smashed vertically into the pavement, hitting it so hard that the spars and struts shattered and pierced the plastic.
I collected the shattered remains of the kite, walked home, and had to explain to my parents what had happened out there. My Mom grounded me for destroying a brand-new (and expensive) kite, but my Dad, a commercial airline pilot, was a little more understanding. "Wind shear" he said, "it caused an immediate loss of lift and an irrecoverable stall. Thank goodness no one was hurt."
That was the day I reconsidered my career choice - I was obviously not going to be an airline pilot.
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e-book takes you step-by-step through making a 120cm (4 ft) tall
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Every kite design in
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- Materials are
plastic sheet, tape and line – and nothing more!
- Tools are a ruler,
scissors and a marker pen - and nothing more!
- All cuts are
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For the greatest chance
of success, I make recommendations regarding the materials. For
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type/strength. Close enough should nearly always be good enough,
since the design is well-tested and should be tolerant of small
differences from my original.
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May 10, 17 06:00 AM
This previously published page is a mixture of informative data and historical background. Also there is also a video of one of my own tetrahedral designs in flight!