With many systems in modern aircraft being electronic, the term avionics has gained popularity, that of which is a combination of the terms aviation and electronics. In aircraft, spacecraft, and even artificial satellites, electronic systems are used for a variety of purposes, ranging from very simple to highly complex functions. Some typical applications include, but are not limited to, flight control systems, engine controls, flight recorders, communications, navigation, threat detection, weather radar, electro-optic (EO/IR) systems, fuel systems, and performance monitors. Altogether, there are seven basic system categories that comprise avionics, those of which we will cover in the following blog.

Cotter pins, cotter wedges, or split pins are small yet crucial locking components made up of thick wire with a semicircular cross-section inserted through a hole to join various parts of a machine. Examples of cotter pin use include securing a crank to its crankshaft or combining a piston rod to a crosshead. In a bicycle, a cotter pin locks the pedal crank to a bottom bracket axle to stop axial motion along the shaft when propelled into the assembly hole. For a steam engine, a cotter joint is tapered to resist thrust. The position of a component being held by a cotter pin is determined through the angle of the wedge. Hence, if the angle of the cotter pin is equal in both pedals on a bicycle, the pedal arms will be situated at a straight angle or 180 degrees from one another. While tapering into a hole, split pins usually get compressed, inducing friction and binding them tightly for security.