A support structure for attaching an engine to an aircraft pylon at front, mid and rear attachment positions thereof, including a front mount joined to the engine and configured to attach to the pylon at the front attachment position and a rear mount joined to a core casing to attach to the pylon at the rear attachment position, each of the front and rear mounts configured to transfer lateral and vertical loads from the engine to the pylon, and the rear mount being spaced from the front mount such that yaw and pitch torques are transferred from the engine to the pylon through the front and rear mounts. The support structure also includes an axial load transfer formation to transfer axial loads from the engine to the pylon and a roll-torque transfer formation to transfer roll torque from the core casing to the pylon.