Figure 2-11.Airloc fastener.

the heavy-duty fasteners. Otherwise, their construction features are about the same. Figure 2-12 shows the parts of a light-duty Dzus fastener. Notice that they include a spring and a stud. The spring is made of cadmium-plated steel music wire, and is usually riveted to an aircraft structural member. The stud comes in a number of designs (as shown in views A, B, and C) and mounts in a dimpled hole in the cover assembly. When the panel is being positioned on an aircraft, the spring riveted to the structural member enters the hollow center of the stud. Then, when the stud is turned about one-fourth turn, the curved jaws of the stud slip over the spring and compress it. The resulting tension locks the stud in place and secures the panel.