Abstract: Test and man-rating of an oxygen generation system required analytical methods for evaluating system performance both in the laboratory and on the aircraft. The Oxygen System Analyzer is capable of monitoring four performance variables which include: (1) system gas flow rate, (2) product oxygen concentration, (3) system outlet pressure, and (4) aircraft cabin pressure. The analyzer is a portable tester designed to be used on a frequent basis to ascertain system performance and assure reliability and safety. The device may be used either in preflight system checkout mode or to assess in-flight performance characteristics and compliance with design specifications. The analyzer is packaged in a flight worthy case (20.times.13.times.8.5 inches, 31 pounds) and operates from a 12 volt rechargeable power system for 8-10 hours. Data is handlogged from digital panel meters.

Abstract: A breathing system (10) is provided for supplying physiologically acceptable breathing gas (oxygen partial pressure greater than that required to prevent hypoxia) to a pilot of an aircraft. The system (10) includes a breathing mask (12) connected to a pressure regulator (14). The pressure regulator (14) is connected to a selector valve (32). Connected to the selector valve (32) is an onboard oxygen generating system (22) and a standby oxygen supply (24). The selector valve (32) selects breathing gas from one of these two sources. Also included in the system is an emergency oxygen bottle (26) connected to the regulator (14). Ambient air is supplied to the mask (12) by an ambient airflow duct (20) if for some reason none of the breathing gas sources (22, 24, 26) provide breathing gas to the regulator (14).