Avionics is a specialization within electronic maintenance and repair. It focuses on aircraft electronics, but encompasses a wide range of job types. An avionics technician is a specialist who is responsible for all the electronics aboard an aircraft as well as the wiring that connects to the electrical system. They run cables, mount antennas, and connect instruments for navigation and engine monitoring. Technicians install radios, autopilots, and passenger entertainment systems. The job demands attention to detail and a commitment to the very highest standards of quality workmanship because they work on flight-critical systems that impact passenger and crew safety.
Some technicians install and troubleshoot avionics equipment on fixed wing aircraft or helicopters. They're responsible to see that everything works properly and none of it interferes with other electronic devices on board. When a device fails, they remove it and send it to a shop where a bench avionics tech performs repairs. In a small facility, a tech may work on the aircraft and in the shop, but in large operations the jobs are separate.
Bench techs may work on navigation and communication radios, autopilots, computers, and even large mechanical assemblies like radar antennas. A large shop may work on hundreds of different items. Technicians are often specialists within one or two areas. The job requires excellent troubleshooting skills and the ability to do intricate, high-reliability soldering on delicate components. Good bench techs have patience, steady hands, and excellent vision. Modern circuit boards are densely populated with tiny integrated circuits. Much of the soldering is done with binocular magnifiers or microscopes.
System trouble-shooters are technicians with years of experience and a tremendous depth of knowledge about commercial aircraft. They may not know the intricacies of the individual components that make up the system, but they know how those parts interact and sometimes counteract one another. Line avionics techs rely on them for accurate diagnosis of difficult problems. There's always a deadline. An aircraft has to fly again shortly, so it seems that these trouble-shooters are constantly on the run.
In the United States, most avionics technicians receive an Associate's degree after graduating from a two-year technical school. The schools certify that a graduate knows electronics, math, and physics. The electronics instruction includes analog and digital circuits, power supplies, radio transmitters and receivers, antenna theory, and more. Specialized material on radar, distance measuring equipment, transponders, control panels, and instruments prepares a student for a career in aviation.
Once a student finds employment, on-the-job training begins with a general familiarization school on the aircraft types the student will encounter. This is an introduction to the specific manufacturer's nomenclature and manuals so that the new employee can find things aboard the aircraft. Large commercial airlines may have their own schools on soldering, test equipment, personal and chemical safety, ramp operations, and much more. In some cases, employees attend classes with the original equipment manufacturer for intensive instruction.
Avionics technicians are employed in several different settings. Most passengers inside a terminal have seen a line tech rushing to replace a black box so that a flight can leave on time, but the bulk of the work around a terminal is done at night. Pilots write-up problems in the aircraft log book during the day. Technicians try to clear those entries at night. They may be updating aircraft software, repairing wiring, or changing black boxes as necessary. The night crew technicians repair those time consuming items that could be deferred overnight, provided that safety is not compromised.
Hangar avionics technicians have the luxury of time, unlike the line techs. Their airplane may be in the hangar for days or weeks. A planner reviews the aircraft records and any new information from the manufacturer, and then works out a schedule to cover all the necessary routine and non-routine maintenance. Teams are assigned and the time required for each task is included on the schedule. Unanticipated problems, like a crushed antenna cable, can introduce delays, but the teams usually manage to get the work finished before the deadline.
Bench technicians work in well-lit, air-conditioned rooms surrounded by the hum of cooling fans. Avionics equipment manufacturers specify the temperature and humidity limits for testing. While not quite "clean rooms," most have dust collection systems and positive air pressure. Floors, benches, and office furniture are specially made to dissipate static electricity. Screen rooms that block electromagnetic interference are used to test extremely sensitive equipment, or to shield the surrounding areas from powerful radio transmitters.