机型指派问题(FAP)是指根据飞机舱位能力、运营成本、潜在收益及飞机可用性,将具有不同舱位容量的飞机指派给各定期航班的问题。它是飞机、机组排班问题的基础,是整个航班计划中的最核心环节。然而,单独的机型指派最优对整个航班计划而言,可能是次优的,甚或是不可行的。本文针对国内航班计划特点,从航班的角度,定义了航班纯度概念,并建立基于航班纯度的机型指派模型。最后,以国内某航空公司干线网络为实例,表明该研究具有很大的理论意义和实践价值。 Aircraft Assignment Issue (FAP) is the issue of assigning airplanes of varying capacity to scheduled flights based on their ability to travel, operating costs, potential revenue and aircraft availability. It is the basis for aircraft and crew scheduling problems and is the core of the entire flight plan. However, the individual model assignments may be suboptimal, or even impractical, for the entire flight plan. This article aims at the characteristics of domestic flight plan, from the flight point of view, defines the concept of flight purity, and the establishment of model based on flight purity aircraft model. Finally, taking a domestic airline network as an example, it shows that the research has great theoretical and practical value.