The professionals who repair and maintain aircraft receive thorough training and are tested rigorously in order to ensure their competence and test the range of their skills. There are three basic divisions into which aircraft technicians fall: aircraft frame mechanics, power plant mechanics, and avionics technicians.
An aircraft frame mechanic is allowed to work on any component of the aircraft except the engines, the instruments and the propellers. These professionals inspect and repair brakes, landing gear, air circulation equipment, pumps, and various other pieces of equipment. Power plant mechanics inspect and repair engines and have some latitude to work on propellers. There are also combination aircraft mechanics - A&P technicians - who are authorized to work on both airframe components and power plants.
An avionics technician is responsible for components used for aircraft navigation and weather detection systems, radio communications, and other instruments and computers that control the engine, and the flight of the aircraft. These components are as vital to an airplane's functionality as the engines or the wings. They may be required to hold additional credentials such as a radiotelephone license (issued by the FC) in order to repair and test the communications gear.
The FAA is the accrediting body for aviation technician schools - currently there are about 175 in the United states. The course of study usually lasts 18 - 24 months and covers the basics of aircraft design and tool use. Some schools offer two and four year degrees in avionics or aircraft maintenance management. Many schools are starting to incorporate the study of the composite materials that are being used to manufacture aircraft today, replacing aluminum and fiberglass.
The FAA certifies all aircraft repair technicians and requires at least eighteen months of experience prior to consideration for certification, although time in a formal training program may be substituted for experience. In addition new aircraft repair technicians and avionics technicians must pass an FAA exam and must keep up continuing education requirements.