Author: Dave Garwood
Edition: Model Aviation - 2012/06
Page Numbers: 111,112,113
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RC SLOPE SOARING - 2012/06

Dale discussed flying with rudder-only control. He warned that a model must be trimmed before launch or you're likely to have a short flight. Remember that back in 1966, multichannel RC radio sets were expensive and unaffordable for many modelers.

More from Dale about radios for Slope Soaring

"Readers concerned with equipment can rest assured that simple rudder-only can be much fun (and still an exciting challenge) and is recommended for beginners. Just remember that a rudder-only glider must be trimmed to fly faster than the speed of the wind over the edge of the cliff, or it will be blown back."

Although a comprehensive look at RC soaring was envisioned, Dale spent most of his time on slope soaring. All seven diagrams accompanying the article pertain to slope soaring. Dale knew the thrill of it.

Movie Project

How Mark Smith designed, built, and flew model gulls for the movie Jonathan Livingston Seagull is one of the most interesting stories in the history of slope soaring. The movie was made before the common use of computer-generated graphics in film; these model gulls had to be flown for the cameras.

The movie company first tried motorized gulls, but found them unsuitable. They turned to one of the soaring stars of the day, Mark Smith, from Escondido, California. Mark had seen success on the soaring contest circuit. By this time, Mark and his father, Rod, were running Marks Models and were known for the successful Windward and Windfree glider designs.

Rod Smith related some of the details

"The motion picture Jonathan Livingston Seagull was filmed in 1973. The attached photos were taken by Dick Tichenor at Torrey Pines in San Diego, California, in 1973, and one was on the cover of RC Modeler magazine in November 1973.

"The seagull was hand-carved out of white foam, covered with stick-on film, and painted with Testors spray-can paint. The yaw stability was accomplished by attaching 3-inch-diameter clear discs at the wingtips, toed in about 3°.

"This was before computer radios, so the control system was strange. The adverse yaw was so bad that the bird was uncontrollable. So the solution was to put the left wing aileron on the rudder stick and the right wing aileron on the normal aileron stick. This gave us our mixing. Move both sticks the same direction and you had normal aileron. Move one stick out and you had, in effect, a tip spoiler so the roll was pretty good. Move both sticks out and both ailerons went up for up-elevator. When inverted, move both sticks in and you could maintain inverted flight. The tail feathers also acted as elevator, but with limited effect, and worked well at normal cruise speed.

"The model gull was required to loop, roll, and fly inverted to meet the requirements of the movie, which featured all these maneuvers, as well as crashing into cliffs and diving into the ocean. We used approximately 15 models.

"Control of the model gulls was an amazing accomplishment back in the day. I recall that Mark said after designing, building, testing, refining, and flying the model gulls for the movie, 'Seagulls have 400-channel radios—one channel for each feather.'"

The Frank Bethwaite, Mark Smith, and Dale Willoughby articles are on an RCGroups web blog (listed in Sources). The Frank Kelly article has its own web address. It will be interesting to see what other magazine articles can be found that document the history of slope soaring.

SOURCES

Transcribed from original scans by AI. Minor OCR errors may remain.