Management Process of a Frequency Response Flight Test for Rotorcraft Flying Qualities Evaluation

ABSTRACT This paper applies the frequency response methodology to characterize and analyze the flying qualities of longitudinal and lateral axes of a rotary-wing aircraft, AS355-F2. Using the results, it is possible to check the suitability of the aircraft in accordance with ADS-33E-PRF standard, whose flying qualities specifications criteria are based on parameters in the frequency domain. The key steps addressed in the study involve getting, by means of flight test data, the closed-loop dynamic responses including the design of the instrumentation and specification of the sensors to be used in the flight test campaign, the definition of the appropriate maneuvers characteristics for excitation of the aircraft, the planning and execution of the flight test to collect the data, and the proper data treatment, processing and analysis after the flight. After treatment of the collected data, single input-single output spectral analysis is performed. The results permit the analysis of the flying qualities characteristics, anticipation of the demands to which the pilot will be subjected during closed-loop evaluations and check of compliance with the aforementioned standard, within the range of consistent excitation frequencies for flight tests, setting the agility level of the test aircraft.

摘要 本文采用频响分析法，对AS355-F2旋翼飞行器的纵向与横向轴飞行品质开展表征与分析。基于研究结果，可依据ADS-33E-PRF标准验证该飞行器的适配性——该标准的飞行品质规范准则以频域参数为核心依据。本研究的关键流程包括：通过飞行试验数据获取闭环动态响应，具体涵盖飞行试验任务中所用仪表的设计、传感器规格的确定、用于激励飞行器的适配机动动作特性定义、飞行试验的规划与实施以采集数据，以及试飞后规范的数据处理、加工与分析。采集的数据经处理后，开展单输入单输出频谱分析。所得结果可用于分析飞行品质特性，预判飞行员在闭环评估过程中所需承受的操作负荷，在飞行试验的一致激励频率范围内验证受试飞行器是否符合前述标准，并确定受试飞行器的敏捷性等级。