Abstract: A locking assembly that mechanically locks an attachment bolt, such as one used to secure a missile launcher to an aircraft, for example, thus preventing the bolt from vibrating loose as a result of vibration experienced during flight. The locking assembly has a spring loaded locking nut that mechanically engages a hex head of an extension shaft that is coupled to the attachment bolt. Transverse pins permit axial movement of the locking nut but prevent rotation thereof. A socket is used to push the locking nut away from the hex head of the extension shaft, so that the attachment bolt can be loosened or tightened. When the socket is removed, a spring pushes the locking nut over the hex head of the extension shaft, locking the attachment bolt and preventing it from turning.