GENERAL APPROACH TO THE ANALYSIS OF THE ASYMMETRICALLY LOADED AIRPLANE FLIGHT LIMITATIONS

摘要

General approach to the analysis of asymmetricallyloaded airplane limitations within the terminalflight phases is presented in this paper. Thegoal of the analysis is to supplement the flight envelopelimitations of the symmetrically loaded airplane,providing the increase of the airplane usesafety.The analysis method is based upon theconcept of the control surfaces authority, theircapability to generate the aerodynamic controllingmoments, and the definition of both, theasymmetric loads that need to be compensatedand maneuvers that are to be performed. As theflight envelope limitations of the symmetricallyloaded airplane positions the airplane lift coefficientfunction to the boundary of linear variation ofthe angle of attack, flight control deflections requiredto compensate the asymmetry and performdemanded maneuver can be considered as additive.The factors defining available controlsurfaces authority are the dynamic pressure andstructure limited deflections. Then, for the knownstructure limited deflections, required maneuverand form of asymmetric load, it is possible todefine limiting flight parameters in the form ofairspeed and lateral wind velocity component.Analysis method is applicable throughout wholeairplane design and life cycle, from the initialdesign stages up to the end-of-life decommissioning.The analysis problem can be solvednumerically for any combination of asymmetricairplane loads. Two presented examples are theinherently asymmetric single propeller airplane(Figure 1.) and jet combat airplane (Figure 2.)asymmetric under wing store.