Detecting Flaws in the Presence of Strong Geometry Signals in F100 Gas Turbine Engine Components

  • Ray T. Ko


The inspection of F-100 gas turbine engine components using the Retirement For Cause (RFC) Eddy Current Inspection Station includes the requirement to scan three common but critical geometries: Antirotation windows (ARW), antirotation tangs (ART) and the live rim (LR) area at the component rim, as shown in Figures 1 and 2. These geometries have a common feature — edges, as shown in Figure 3 — that presents a challenge to successful inspection. The edges are sources of strong geometry signals that often have a higher amplitude than flaw signals, thus making a conventional amplitude inspection technique difficult. Therefore, a “frequency select” technique was developed which uses the frequency difference as a flaw determination criteria [1,2]. Using this technique, the RFC System has successfully detected both EDM notches and fatigue cracks in these geometries located in engine components fabricated of IN-100, waspaloy and titanium.


Fatigue Crack Fast Fourier Transform Frequency Difference Index Direction Threshold Technique 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    R. T. Ko, W. C. Hoppe, D. A. Stubbs, D. L. Birx, B. Olding and G. Williams, “An Update on Automatic Positioning, Inspection, and Signal Processing Techniques in the RFC/NDE Inspection System,” in Review of Progress in Quantitative NDE, 6, edited by D. O. Thompson and D. E. Chimenti (Plenum Press, New York, 1987).Google Scholar
  2. 2.
    W. C. Hoppe and D. A. Stubbs, “Automatic Eddy Current Inspection of Antirotation Windows in F100 Engine Compressor Air Seals,” in Review of Progress in Quantitative NDE, 4, edited by D. O. Thompson and D. E. Chimenti (Plenum Press, New York, 1985).Google Scholar

Copyright information

© Springer Science+Business Media New York 1989

Authors and Affiliations

  • Ray T. Ko
    • 1
  1. 1.A Division of Arvin/CalspanSystems Research LaboratoriesDaytonUSA

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