Flight envelopes typically do not describe flight at asymmetric attitudes where sideslip may be present, which limits the performance view of aircraft. Hence, to expand on flight performance assessment, the asymmetric attitude flight envelope is developed for mathematical models of a military and a business jet. This envelope, called the angle of attack vs. sideslip envelope, is a bounded curve that describes the full extent to which an aircraft can be trimmed at asymmetric attitudes. This envelope is comprised of trim points developed by optimizing the dynamics of an aircraft model while subject to constraints of aircraft control limitations, thrust capability and structural integrity. The use of two aircraft models here demonstrates the applicability of this methodology and allows discrimination of performance requirements between the two models. Also, this work contributes to the relatively scarce literature on modeling and performance assessment of flight at asymmetric attitudes. Following envelope development, the observed flight operating limitations and properties of both aircraft models are discussed. The envelope data revealed important insights, which were previously not handily available, into performance requirements at asymmetric attitude flight regimes. Further, the results also depicted aircraft operating limitations due to factors like the control surfaces, propulsion and aerodynamic capability, and structural integrity, at the extremes of the aircrafts' envelope. The performance insights were gained graphically via analysis of the variation of factors like trim control requirements and flight parameters. Lastly, the possible applications of the full flight performance results, in the design of aircraft control systems, are highlighted.
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