Radio Control of Model Flying Boats

A new method of carrying on flying-boat hull design involves radio control of free-flight models. The scale factors of the models are such that severe weight and space limitations are imposed on the radio-control equipment, considering the complexity of control. Seven independent channels capable of simultaneous operation are needed. Five accomplish proportional positioning and two perform switching operations. A single radio-frequency carrier is used, amplitude-modulated by seven control tones. The factors affecting the positioning accuracy are discussed. A compensating circuit is described which corrects for variations in receiver output with charges of battery voltage and distance from the control station. Over-all positioning accuracy is plus or minus 4 per cent. Operating experience includes nearly 1000 test runs utilizing scale models of three different types of flying boats.