title: Onboard oxygen generation systems.
abstract: During the 1970s, the development of onboard oxygen generation systems (OBOGS) progressed through ground and flight test phases to the point where a second-generation concept is now production qualified and additional alternatives are being evaluated. This paper reviews the development of OBOGS and assesses the current state of the art of these systems. High-purity fluomine systems, developed for flight demonstration and qualified for production application, are discussed. Development of enriched air molecular sieve systems for laboratory and flight applications is described, along with a recent study of a permeable membrane-based aircraft oxygen enrichment concept. Capabilities and characteristics of the various OBOGS concepts are compared, showing the greater compliance of high-purity fluomine systems with the current oxygen military standards while noting the advantages of the reduced interface complexity of enriched air systems. Recommendations for future OBOGS development are presented, emphasizing the need to coordinate the development of specifications and hardware so the optimum compromises between physiological requirements and engineering feasibilities can result in OBOGS that best satisfy the metabolic needs of aircrew members.
mesh_terms: D000401:Aircraft / Q000295:instrumentation*; D008567:Membranes, Artificial; D010100:Oxygen / Q000600:supply & distribution*
chemical_list: D008567:Membranes, Artificial; D010100:Oxygen