Analysis and study on the minimum allowable clearance between civil aircraft fan cowling and flaps

Abstract In the development of civil aircraft, the evaluation of the minimum allowable clearance between the fan cowl opening and flaps is a crucial factor in determining the maintainability of civil aircraft and an essential aspect of the development process for civil aircraft models. To ensure that the aircraft does not experience poor maintainability or interference issues during ground maintenance due to insufficient clearance, this paper proposes a clearance analysis method to study the minimum allowable clearance between the fan cowl opening and flaps during maintenance. The paper outlines the approach to clearance analysis, explains the principles of clearance control, and discusses factors influencing clearance. Finally, using a specific aircraft as a case study, the paper provides a detailed description of the factors to be considered in calculating and analyzing the minimum allowable clearance between the fan cowl opening and flaps. The research results also demonstrate the practical engineering value of this clearance analysis method.