CERTAIN PORTIONS ARE ILLEGIBLE , IT IS BEING RELEASED IN THE INTEREST OF MAKING
A review of the factors affecting the helicopter market for the past, present, and future is presented. The trade-offs involving acquisition cost, mission reliability, and life-cycle cost are reviewed, including civil and military aspects. The potential for advanced vehicle configurations with substantial improvements in energy efficiency, operati.ig economics, and characteristics to satisfy the demands of the future market are identified. Advanced propulsion systems required .o support these vehicle configurations are, in turn, discussed, as well as the component technology for the engine systems. Considerations for selection of components in areas of economics and efficiency are presented.
Plasma-sprayed zirconia gas path seal technology: A state-of-the-art review
The benefits derived from application of ceramic materials to high pressure turbine gas path seal components are described and the developmental backgrounds of various approaches are reviewed. The most fully developed approaches are those employing plasma sprayed zirconium oxide as the ceramic material. Prevention of cracking and spalling of the zirconium oxide under cyclic thermal shock conditions imposed by the engine operating cycle is the most immediate problem to be solved before implementation is undertaken. Three promising approaches to improving cyclic thermal shock resistance are described and comparative rig performance of each are reviewed. Advanced concepts showing potential for performance improvements are described.
Research requirements to reduce empty weight of helicopters by use of advanced materials
Utilization of the new, lightweight, high-strength, aerospace structural-composite (filament/matrix) materials, when specifically designed into a new aircraft, promises reductions in structural empty weight of 12 percent at recurring costs competive with metals. A program of basic and applied research and demonstration is identified with the objective of advancing the state of the art to the point where civil helicopters are confidently designed, produced, certified, and marketed by 1985. A structural empty-weight reduction of 12 percent was shown to significantly reduce energy consumption in modern high-performance helicopters.