Robust ground-based Diagnostics, Prognostics and Health Management information

A decade ago, (1998, 1999), Joint Strike Fighter (JSF) F-100 engine seeded fault testing was conducted at Pratt & Whitney, Florida, in support of Diagnostics, Prognostics and Health Management (PHM) system design. Multiple sensor approaches were invited to monitor the seeded fault testing, including an Independent Research and Development (IR&D) system termed the robust laser interferometer (RLI). The "then" RLI provided a non-contact, wideband (0 to 260 kHz), large dynamic range (180 dB demonstrated in acceleration) physical measurement capability, with output information displayed in time series or spectrum formats for displacement, velocity or acceleration. In particular, the IR&D RLI was offered the opportunity to make line-of-sight vibration measurements, as a referee sensor, during the testing effort. The robustness and quality of the RLI measurements have been documented, including at various IEEE AeroConf Meetings over the past decade. At the time of the testing, it was strongly suggested that the prudent evolution for the RLI technology would include both "point-and-shoot" and fiber-optic ground-based systems prior to pursuit of "flyable" fiber-optic diagnostics and PHM capabilities. That the RLI was not immediately accepted as a \´flyable component\´ of the JSF PHM was quite reasonable. In the interim, it is suggested that the continued evolution of the RLI technology provides a meaningful baseline for development of a robust, ground-based diagnostics and PHM information tool-set. Advances in technology and progress in related knowledge development are being investigated, along with the core earlier findings for supporting advanced aviation PHM. This includes ground-based (near term) capabilities.