OBJECTIVE: Develop a sensor for detecting toxic contaminants in oxygen produced by aircraft On-Board Oxygen Generating Systems (OBOGS). DESCRIPTION: Aircraft equipped with On-Board Oxygen Generating Systems (OBOGS) provide aircrew breathing oxygen using molecular sieves and Pressure Swing Adsorption (PSA) technology. The OBOGS selectively filters compressed air from the aircraft's engine to remove nitrogen and other gaseous contaminants to provide the aircrew with an oxygen enriched breathing gas. During shipboard operations, Navy aircraft are particularly vulnerable to excessive levels of toxic byproducts from ingesting the jet exhaust from other aircraft. Under suboptimal operating conditions, toxic byproducts can breach the OBOGS and enter the aircrew's oxygen supply. NAVAIR is developing an oxidizing catalyst to eliminate these toxins, but a sensor is needed to determine when the catalyst may be losing effectiveness. The sensor must be capable of detecting, as a minimum, low level hydrocarbons including carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), and aliphatic and aromatic hydrocarbons that are byproducts of incomplete jet fuel and lubricant combustion. The sensor must be capable of operating in an oxygen rich environment from 21 to 100% oxygen. Oxygen system pressures range from 24 PSIA to 100 PSIA. Operating temperature ranges from -40C to +160C (objective), or from -10C to +160C (threshold). The sensor must be capable of providing a visual indicator that can be inspected by a maintainer, and an electronic output signal that can interface with an aircraft's caution and warning system to alert the aircrew. The warning should be triggered when toxic hydrocarbon contaminants have breached the oxygen system and oxidizing catalyst and entered the pilot's breathing oxygen. Current sensor technology consists primarily of electrochemical cells and solid state detectors capable of sensing single components. These sensors tend to lack the response time, reliability, and robustness needed for military aircraft. Compact, multi-component, highly reliable sensors that do not drift over time are required for this application. The ideal technology will have sensitivity in the part-per-million range, be compact and light weight, and require minimal power. Weight limits should not exceed 1 pound, and volume limits should not exceed 2.5 inches in height, 10 inches in width, and 8 inches in depth. PHASE I: Determine concept feasibility and should culminate with a working prototype to demonstrate the sensor's capability of detecting toxic hydrocarbons along with the capability of providing a visual indicator for maintainers, and an electronic output to interface with the aircraft's caution and warning system. Phase I shall include a draft of systems requirements for aircraft integration including environmental qualification testing. PHASE II: Refine the operational system requirements based on the aircraft selected for flight testing. Utilize the Systems Engineering Process for solidifying the system requirements, conducting preliminary and critical design reviews, and producing flight worthy prototype hardware for concept demonstration testing. PHASE III: Finalization of the design, low rate initial production, followed by full production. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Commercial and civil aviation are transitioning from traditional high pressure gaseous and liquid oxygen systems to OBOGS. Additionally, point-of-use oxygen generators are being developed for ground operations, mobile hospitals, emergency response vehicles, and mass casualty response systems. Many of these applications have no single sensor/system for verifying the quality of the oxygen that is produced. Developing a multi-component sensor that measures contaminants in OBOGS and other point-of-use oxygen generators has significant military and commercial application.