Development of On-line Fuel Tank Oxygen Sensor for Aircraft

Operating airplanes with flammable vapors in the fuel tank presents an avoidable risk of explosion. In fact, the elimination of flammable vapors in fuel tanks has made it to the National Transportation Safety Board's (NTSB) "Most Wanted" list of aviation safety improvements. Inerting systems displace air in the fuel tank with nitrogen and thus lower the oxygen content to a level that does not support combustion. Unfortunately, there are no flight certified sensors capable of monitoring the gasses inside the fuel tank. An oxygen sensor that operates in this harsh environment is needed to control the inerting system. InterSpace proposes to continue development of a field prototype oxygen sensor capable of operating in an aircraft fuel tank. This development builds on our Phase I laboratory prototype in which we demonstrated the feasibility of detecting oxygen in the presence of fuel vapor. The sensor is intrinsically safe in fuel tank environments and avoids fouling problems associated with optical sensors currently under development. InterSpace will develop the electronics to drive the sensor; construct and test the sensing element; integrate pressure and temperature transducers with the sensor; and package the electronics, sensors, and interface into a field prototype unit.