Downloaded from https://www.everyspec.com ADS-79D-HDBK FIGURE D-16. Aft hanger bearing energy CI (fine sand fault) D.7.7 Summary. Bearing CI development starts with an examination of the physical properties of the bearing and the calculation of fault frequencies. Energy bands are selected based on this information, with attention paid to the frequencies of other vibration sources that should be excluded from the band. Once a band has been selected for a CI, its effectiveness must be tested and confirmed by seeded fault testing or teardowns from the fleet.
This approach was used to develop the AH-64 Hanger Bearing Energy CIs, and they have demonstrated their effectiveness in detecting faulted bearings. 99