TY - CPAPER AB - Helicopter systems, and in particular helicopter transmissions, pose severe problems of lubrication and these are reflected in shorter overhaul periods and lower reliability than other, comparable systems in fixed wing aircraft. Many of these problems may be met by the introduction of new materials, such as ceramic engine bearings, flexible rotor parts, new gear steels and synthetic transmission oils. One stumbling block should, however be recognised. Helicopters, though important and irreplaceable for some applications, are not produced in large numbers and the cost of applying new technology can be prohibitive if a significant amount of development work needs to be done. Even the validation of a new material is enormously expensive, involving as it must, helicopter flying time. It is these costs, rather than the merits or availability of new materials and technologies that may be the main barrier to improvements in helicopter lubrication. AU - Spikes,HA EP - 74 PY - 1986/// SP - 59 TI - HELICOPTER LUBRICATION. ER -