V-22 rotor track and balance on-board and ground station functionality and field experience

The V-22 tiltrotor aircraft accomplishes key onboard functions using the Vibration, Structural Life and Engine Diagnostics (VSLED) system. Several key Health, Usage, and Monitoring System (HUMS) objectives are accomplished by processing VSLED data in the Comprehensive Automated Maintenance Environment Optimized (CAMEO) ground station. VSLED acquires Rotor Track and Balance (RTB) vibration data and calculates rotor blade weight adjustments and blade pitch change adjustments to reduce 1 per rev vibrations induced by the two proprotors and to match thrust for the two proprotors while in airplane mode. The CAMEO ground station includes a maintenance support software module called the “RTB Tool” where VSLED RTB adjustments are further processed and diagnosed as required to assure the RTB process stays on course and to provide maintainers with additional requirements when more complex diagnostics for VSLED system or mechanical problems are suspected. This paper presents an overview of the onboard system functions and CAMEO´s RTB Tool functions used in the rotor smoothing operation. A description of the flight data acquisition, onboard processing and ground station processing is also provided. The CAMEO RTB Tool module displays data in graphical and tabular format. Some examples of RTB operations are presented.