11-Mar-2019 Source: USPTO
A rotorcraft, such as a tiltrotor aircraft having helicopter and airplane modes, includes an airframe, an engine and an engine mount assembly for coupling the engine to the airframe. The engine includes an engine lug forming an aperture. The engine mount assembly includes a mount having an aperture substantially aligned with the engine lug aperture. A sleeved bolt assembly extends through the apertures to secure the engine lug to the mount. The sleeved bolt assembly includes a bolt undersized relative to the apertures forming a circumferential gap within the apertures, a sleeve disposed around at least a portion of the bolt substantially filling the circumferential gap and a nut adapted to thread onto a threaded portion of the bolt. The use of the undersized bolt within the sleeve permits increased clearance between the sleeved bolt assembly and the engine while maintaining strength requirements in high load environments.