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Descriptions are given of two captured helicopters, one driven by electric power, the other by a gasoline engine. An account is given of flight tests of the gasoline powered vehicle. After 15 successful flight tests, the gasoline powered vehicle crashed due to the insufficient thrust. Also discussed here are the applications of helicopters for military observations, for meteorological work, and for carrying radio antennas.
A concept for a multi-hull weightlifting airship is presented. The concept is based upon experience in the design and handling of gas-filled balloons for commercial purposes, it was first tested in April, 1972. In the flight test, two barrage balloons were joined side-by-side, with an intermediate frame, and launched in captive flight. The success of this flight test led to plans for a development program calling for a powered, piloted prototype, a follow-on 40 ton model, and a 400 ton transport model. All of these airships utilize a tetrehedric three-line tethering method for loading and unloading phases of flight, which bypasses many of the difficulties inherent in the handling of a conventional airship near the ground. Both initial and operating costs per ton of lift capability are significantly less for the subject design than for either helicopters or airships of conventional mono-hull design.
Rotorcraft drive trains must withstand enormous pressure while operating continuously in extreme temperature and vibration environments. Captive components, such as planetary and spiral bevel gears, see enormous strain but are not accessible to fixed instrumentation, such as a piezoelectric transducer. Thus, it is difficult to directly monitor components that are most susceptible to damage. This innovation is a self-contained data processing unit within a specialized fixture that installs directly inside the rotating pinion gear in the gearbox. From this location, it detects and transmits high-resolution prognostic data to a fixed transceiver. The sensor is based on microelectromechanical systems (MEMS) technology and uses innovative circuit designs to capture high-bandwidth data and transmit it wirelessly from inside an operational helicopter transmission. With Ridgetop's advanced MEMS-based sensor, researchers have, for the first time, been able to extract high-resolution acoustic signatures wirelessly from sensors within the transmission that would otherwise be muffled by background gear noises. Ridgetop's innovative instrument will help researchers perform dynamic analysis of gear interaction and develop improved designs for gear components. In addition, data from this instrument can be used to validate new algorithms that detect and predict faults based on external acoustic signatures, for prognostic purposes. The result of this work will be an improvement in safety, performance, and cost for future generations of rotating components.