Development of Control Line model aircraft began with tethered models that were flown around a fixed anchor point. In 1879, Victor Tatin demonstrated a compressed-air-powered aircraft on a specially constructed circular pad in Chalais-Meudon, France. Sixty years later, Oba St. Clair of Yamhill, Oregon took this one step further.
In 1936, St. Clair began constructing a Berliner Joyce Free Flight model from plans featured in the August 1935 issue of Modern Mechanics and Invention magazine. As he was nearing completion, he realized that his model would quickly be damaged or lost in the forests that surrounded his home. He decided the solution was to fly the airplane around in a circle attached to a single line. If there was even the slightest breeze, the model would begin to climb and descend on its own though, so St. Clair decided he needed more control.
During the fall of 1936, St. Clair devised a four-line control system that he called “full-house” and installed it in a new airplane that he built called the Miss Shirley (named after his just-born daughter). With no wire on-hand, St. Clair used fishing line, but this he found did not stretch equally. To allow for equal stretching, he used a large handle with four poles attached, letting him to quickly take up any slack in the lines. The “full-house” allowed him to control the elevator, ailerons, and throttle. On July 4, 1937, he made his first successful flight. Word spread quickly and numerous articles were written, highlighting this new form of model airplane control.
It was not long before other modelers began developing and marketing Control Line systems. In 1939, the Stanzel brothers began advertising their Tiger Shark, and in 1940, Jim Walker unveiled his Fireball. In no time, Control Line models became all the rage, replacing Free Flight models on the shelves of local hobby shops.
Play the video above to see the unveiling of the reproduction the Miss Shirley to the National Model Aviation Museum on July 20, 2012.
Read Oba St. Clair's biography at https://www.modelaircraft.org/files/StClairOba.pdf
Visit Shirley St. Clair's site featuring her father Oba St. Clair at http://obastclair.com/index.html