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


  • João Otávio Falcão Arantes Filho Instituto de Pesquisas e Ensaios em Voo
  • Donizeti de Andrade Instituto Tecnológico de Aeronáutica


Flight characteristics, Helicopters, Flight Tests, Frequency-domain analysis


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.

Author Biographies

João Otávio Falcão Arantes Filho, Instituto de Pesquisas e Ensaios em Voo

João Otávio Falcão Arantes Filho is 1st Lieutenant at Força Aérea Brasileira and received his master's degree from the Instituto Tecnológico de Aeronáutica in 2016. He is a flight test engineer of Divisão de Ensaios em Voo at Instituto de Pesquisas e Ensaios em Voo. 

Donizeti de Andrade, Instituto Tecnológico de Aeronáutica

Donizeti de Andrade received her Ph. D.'s degree from the Center of Excellence in Rotary Wing Aircraft Technology (CERWAT), School of Aerospace Engineering, Georgia Institute of Technology (Georgia Tech) in 1992. He is an associate professor at Instituto Tecnólogico de Aeronáutica.






Original Papers