A Multilayered Approach for Enhancing Rotorcraft Drive System Diagnostics

The Sikorsky Aircraft Corporation (SAC) and the U.S. Army Aviation Development Directorate (ADD) - Aviation Applied Technology Directorate (AATD) are jointly sponsoring the Capability-Based Operations and Sustainment Technology-Aviation (COST-A) program. The objective of COST-A is to demonstrate an integrated set of high-value diagnostics, prognostics, and system health management technologies that reduce the maintenance burden, without sacrificing safety, of six different rotorcraft systems, including the drivetrain. In general, existing rotorcraft health and usage monitoring systems (HUMS) systems are very effective, providing fault detection capability for critical drivetrain components, and providing other important HUMS functions for the aircraft. Despite the effectiveness of current HUMS systems, opportunities still exist for improvements. Technologies were therefore developed under COST-A to address these opportunities, including measurements or estimates of key drive system loads, improved data quality algorithms, new or improved condition indicators and related algorithms, and a drive system fault/failure mode reasoner. The focus of this paper is to highlight the COST-A drivetrain efforts developed and applied to improve drive system diagnostic performance.