This paper presents a new methodology for obtaining surrogate models suitable for the preliminary design of aircraft application systems. The methodology is based on a dimensional and sensitivity analysis adapted to the needs and constraints arising from multidisciplinary design. It enables simpler and lighter models to be obtained, with satisfactory predictive accuracy over a large range of validity. These surrogate models can cover a very large area of applications, where the components may vary from very small to very large sizes, because of their broad range of validity. Avoiding the reconstruction of the model offers advantages in terms of capitalization and justifying the concept of reuse. The proposed approach is applied to generate surrogate models of a permanent magnet brushless motor used in two types of applications: one is for the preliminary design of a flight control electromechanical actuator and the other is for the preliminary design of an electric propulsion system for a multirotor drone.