Inspection of helicopter blades in field applying vibration diagnostic techniques

The development of non-destructive testing methods for aircrafts, in particular vibration diagnostics, nowadays makes it possible to make a transition to predictive maintenance. To ensure such maintenance, the hidden faults of structures at an early stage of development to be diagnosed. Vibration diagnostic techniques are already used for helicopters and considered as promising but most helicopters do not have on-board systems. An approach that does not require specialized onboard equipment is needed. To be effective such an approach should provide diagnostics in field conditions using a one-time inspection. Application of the system’s prototype, which meet these requirements is suggested and discussed in this paper. Workability of the methods used has been demonstrated in testing of healthy and aged sets of main rotor blades. The method of blades state assessing using modal diagnostic parameters are briefly described and comparison of diagnostic parameters between healthy and aged blades are discussed.