Recirculation Air Cycle Environmental Control System for Helicopters

Environmental control systems for helicopters are desirable to increase comfort, promote cooling of electronic gear, and enhance pilot effectiveness. An optimized design is important to minimize weight, power extraction, and operating costs. This paper discusses a unique type of small, lightweight air cycle environmental control unit that has been developed specifically for helicopters. In comparison to other units, it offers the advantages of a lower power penalty, lower fuel energy and maintenance requirements, and increased reliability.