Disturbance Rejection Handling Qualities Criteria for Rotorcraft

Aeronautical Design Standard ADS-33E-PRF is lacking in a viable hover/low-speed, short-term disturbance rejection criteria to design and analyze hold modes. The Disturbance Rejection Bandwidth and Peak criteria were developed to fill this gap, have been successfully used for design and analysis on many programs, and will be incorporated in the next revision of ADS-33 (revision F). This paper documents the development of these disturbance rejection criteria, from their theoretical background, to examples of their correlation with the rejection of physical disturbances, to the selection of the DRB boundaries for different hold modes. Simple, single-axis examples are used where appropriate to clearly demonstrate basic concepts. In addition, flight data, including assigned Handling Qualities Ratings, from a variety of sources are used to motivate the location of the DRB boundary values.