Aircraft Chemical Sensor Arrays for Onboard Engine and Bleed Air Monitoring

Makel Engineering Inc. (MEI) is developing flight capable chemical microsensor arrays for in situ monitoring of high temperature bleed air and turbine exhaust in jet engines. The proposed chemical sensor probes will be a new class of onboard engine instrumentation for real time monitoring engine and bleed air system operation in flight. Sensor arrays developed by MEI have been demonstrated for ground tests to quantify composition of critical constituents in turbine engine exhaust products, including CO, CO2, NOx, O2, and HC (unburned hydrocarbons). There currently is no flight capable instrumentation for real time measurement of high temperature gas streams from engine bleed air or the turbine exhaust. Ground test demonstrations with high temperature capable (500 to 600oC) solid-state chemical microsensors have shown the potential value for engine health monitoring and detection of engine faults or abnormal operations from ingestion of high moisture levels or particulate from volcanic emissions. The development of flight qualified engine sensors that can measure key chemical species will enable a new level of aeronautical vehicle health management. Phase I of the program demonstrated approaches in sensor miniaturization and robust probe design that enables placement of multiple species in a compact single port. Phase II will develop the next generation prototypes targeting specific engine and bleed air systems for demonstration, validating design choices and proving system performance in a realistic environment for each application.