Changing law of launching pitching angular velocity of rotating missile

In order to provide accurate launching pitching angular velocity（LPAV） for the exterior trajectory optimization design, multi-flexible body dynamics（MFBD） technology is presented to study the changing law of LPAV of the rotating missile based on spiral guideway. An MFBD virtual prototype model of the rotating missile launching system is built using multi-body dynamics modeling technology based on the built flexible body models of key components and the special force model.The built model is verified with the frequency spectrum analysis. With the flexible body contact theory and nonlinear theory of MFBD technology, the research is conducted on the influence of a series of factors on LPAV, such as launching angle change, clearance between launching canister and missile,thrust change, thrust eccentricity and mass eccentricity, etc. Through this research, some useful values of the key design parameters which are difficult to be measured in physical tests are obtained. Finally,a simplified mathematical model of the changing law of LPAV is presented through fitting virtual test results using the linear regression method and verified by physical flight tests. The research results have important significance for the exterior trajectory optimization design.     

航空货运代理人法律地位辨析

航空货运代理人的法律地位随着货运代理业的迅猛发展发生变化，不再单纯以代理人的身份参加航空运输活动，在实践中有时也以承运人的身份出现。应当结合合同内容、航空货运单、合同履行情况、交易习惯等综合认定航空货运代理人的法律地位。在法律层面承认航空货运代理人缔约承运人身份，同时货运代理业亦应加强自身监管，完善行业规范。