Establishment of a remotely piloted helicopter test flight program for higher harmonic control research

Abstract

An analytical research study was begun on a helicopter vibration reduction concept known as higher harmonic control (HHC). To supplement this research, a helicopter flight test program was established to generate flight test data in support of the NPS HHC research efforts. To accomplish this task, a remotely piloted helicopter was chosen as the test vehicle. The research efforts for HHC studies, the selection and acquisition of an RPH capable of completing the intended research mission, and the preliminary analysis of the RPH's flight control system for modification to an HHC configuration. A brief overview of helicopter vibrations and HHC fundamentals, along with an in-depth description of the selected RPH, is presented. Preliminary analysis of the RPH's flight control system includes the determination of associated freeplay and torsional constant values for the flight control components and the calculation of the necessary actuator torque requirements for HHC actuation. This research effort is the first stage of a long tern program designed to provide NPS with an in house asset capable of generating HHC flight test data in support of analytical research.