Free Flight: Duration
NEW and different: the Thunderbugs' "Called-Time" event. As invented by John Ferrer, the competition concept is applied to ROG outdoor rubber-power models, but it seems applicable to other classes, as well. It's simple. Announce a predicted flight time. Make a flight. The absolute difference between the actual and predicted flight time is your score. Lowest total score for three flights wins. Enter as often as you like. At the first trial of the event, the lowest three-flight score was nine seconds. Scores on individual flights ranged from 1/3-sec. to 45 sec. The event was greeted with enthusiasm by the Thunderbugs' membership and will be included in future contests. Irv Acker has donated a trophy for the first person to post a three-flight score of less than one second.
Free Flight: Duration
FUTURE SHOCK is now! For some 90% of Free Flight applications, the time-proved materials of the Thirties-balsa sticks, Japanese tissue. Ambroid glue (or a similar one of your choice), and nitrate dope (perhaps with an overcoat of fuel-proofer)-work just fine. Why change when you have a winner? But we have changed in many areas. While a good wood prop is hard to beat for many engine-power applications and for any serious "outdoor" rubber-power endeavor, a succession of space-age materials has largely taken over for increasingly severe engine-power applications: molded polystyrene, molded nylon, molded fiberglass-reinforced nylon, unidirectional fiberglass in epoxy, and unidirectional carbon-fibers in epoxy.
Free Flight: Duration
STRANGE configuration. I saw a photo of a wind-tunnel model, similar to the one shown in the sketch, being tested at Langley Research Center. Thinking it might have some conceivable relation to Free Flight modeling, I checked it out with my chief technical consultant, W. Hewitt Phillips. As the configuration was originally envisioned by Julian Walkowitz, an engineer at Wright Patterson AFB, the wing and tail joined at the tips of the high-aspect-ratio surfaces. The idea was that the wing and tail would brace each other, giving a stiffer structure and hence a higher flutter speed. However, the stiffness increase is not nearly so great as its truss-like front-view appearance would lead one to believe. Raise the nose a bit, and the whole thing suddenly becomes a lot thinner. The idea was applied, in somewhat modified form, by Burt Rutan, to a proposed agricultural aircraft looking somewhat like my sketch.
Free Flight: Duration
FOAM FAME. Anthony Vaughn's Nats-winning Indoor Hand-Launch Glider has new technology. Tony's 1982 win was the culmination of experimentation with foam gliders spanning 10 years. Beginning with tiny 12-inchers to be flown under streetlights at night, he progressed to slightly larger gliders when an armory having a 37-ft. ceiling became available for flying. Feeling that somewhat larger gliders would fly longer, he built some with 50 sq. in. of wing area having wingspans of 16-17 in. and weights of about 6 grams. There was only one problem; the wings folded on the launch. This was cured by gluing tissue to the wing surfaces, top and bottom, and soon he was getting flights of 40 to 42 sec.
Free Flight: Duration
IN THE LEAD ITEM in my January 1984 column, titled "Strange configuration," I presented the "joined-wing" concept, although I didn't call it that, invented by Dr. Julian Wolkovitch. Shortly after publication of that issue (and before my copy arrived!) I received a phone call from Dr. Wolkovitch, and later a copy of a letter addressed to the Editor, taking me to task for many aspects of my presentation. Dr. Wolkovitch's letter follows: December 4, 1983
