Conventionally, the aircraft routing model is formulated with the time- space network. We substitute the space dimension with the aircraft dimension in the network. The aircraft routing model for the round trip flights rooted at its home base (radial flights) can take advantages of this time-aircraft network. It can be formulated as a minimum cost flow problem with a bundle of side constraints, simple equality constraints. This model is applied to a real-world case with radial flights and solved with the branch-and-bound algorithm. The computational results show that only a few branches are needed. We also test this model with more general cases and obtain promising outcomes.