Tech Briefs

Engineers deliver major throughput enhancement to Air Force engine maintenance depot.

AFRL manufacturing technology engineers, working with personnel from the 76th Maintenance Wing's Software and Propulsion Maintenance Groups at the Oklahoma City Air Logistics Center (OC-ALC) and Wyle Laboratories (formerly Veridian Engineering), delivered a major configuration upgrade and improved the inspection process for the Air Force (AF) Eddy Current Inspection System (ECIS) at OC-ALC, Tinker Air Force Base (AFB), Oklahoma. These ECIS improvements are part of AFRL's Engine Rotor Life Extension program. With investments exceeding $80 million, the ECIS program addresses an AFRL initiative to extend the useful life of turbine engine components and reduce the cost of replacing aging engine components in the AF's fighter and bomber fleets.

ImageEddy current inspection uses electromagnetic induction to detect flaws in conductive materials. The current ECIS station consists of a large electronic manipulator arm that rides on a stable granite block, a turntable to rotate the part throughout the inspection, and an electronic control console (see figure). An engine rotor disk clamped to the turntable rotates as directed by the inspection program. The manipulator arm carries an eddy current probe and maneuvers over, around, and through various areas of the disk. Using an assortment of probes, the system collects information from the engine disk and uses this data to indicate defects in the disk's different geometric features. AFRL's ECIS upgrade improves the speed of communications between the ECIS station computer and the robotic inspection head and thus enables faster and more efficient inspection of engine parts. New digital software signal processing filters replace the current hardware analog filters, significantly improving reliability and minimizing system downtime. The upgrade also consolidates the system's electronics and wiring from a three-bay cabinet to a single-bay cabinet. As a result of these enhancements, OC-ALC personnel have substantially decreased F100 and F110 engine inspection cycle times, which will allow them to accept future F119 and F135 engine inspection tasks.