摘要 |
A barrier filter for use in an helicopter to remove contaminants from intake air prior to delivery to an engine. The helicopter has an intake and a peripheral external surface adjacent to the intake. The filter includes a pleated filter element mounted flush across the intake such as to meet the contour of the peripheral external surface. The filter element comprises a porous filter media and having a surface area such that a calculated speed of air flowing through the filter, when the engine is operating at take off power (TOP) or military intermediate rated power (IRP), is less than about 30 ft/sec. The filter may be retrofit into helicopters having other contaminant removal systems. Preferably, the filter is positioned such that intake air is delivered to the engine at a pressure which is substantially independent of whether the helicopter is moving in a forward direction or hovering with no forward motion.
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