Aircraft and military ground vehicles are exposed to extreme environmental conditions, not the least of which is vibration. Safety and reliability considerations have led to a variety of locking mechanisms. Until recently, the most effective solution for securing switches, sensors, hydraulic actuators and many other external components was safety wire. A new locking washer concept has been developed that provides safety, quality and cost advantages over safety wire for many of these applications. This concept has found use in military land vehicles, helicopters and aircraft including over 400 fastening applications on the F-22 fighter.