An engine is mounted on a structure by an intermediate structure assembled by flanges, to the structure and to the engine, where a rigid structure connects the flanges. This arrangement enables design of the structure to be simplified while allowing a substantial overhang when it is sought to mount the engine by the plane of its center of gravity, while being obliged to move the mounting structure away from it. The intermediate structure is resistant to forces resulting from the overhang, and also allows assemblies that are favorable to a balanced transmission of forces to the structure and a satisfactory ability to filter vibrations.