The engine is so called “the heart of aircraft”; it affects not only flight safety, but also entire aircraft operation cost. The expensive engine maintenance cost is generally about half of the maintenance cost of the whole aircraft. Therefore, it is an essential for airlines to raise the efficiency of engine maintenance and to reduce the maintenance cost. Currently the engine maintenance shop is facing even more severe challenge of dropping cost and improving competitiveness. In this research several main factors are specified in engine shop visit consideration, and the method of Genetic Algorithm (GA) is applied to investigate the optimum scheduling of engine shop visit. Furthermore, an empirical study is provided in order to show the practicability and usefulness of this method, and the Pratt & Whitney JT8D-200 engines is selected as the object; a view of soft time control and full life cycles is also adapted. It is found that a periodic of every 3 times of
shop visits will induce a minimum direct maintenance cost; and three times
shop visit within 12,000 cycles is the most economic arrangement, which
may have several set of optimum solutions.