Aviation Maintenance Technicians (AMTs), also known as aircraft mechanics, are responsible for keeping aircraft in air-worthy condition. They perform regularly scheduled inspections and maintenance, as required by the Federal Aviation Administration (FAA). Avionics Technicians or Aircraft Electronic Technicians (AETs) are AMTs with advanced avionics training and certification. Besides routine maintenance and inspections, work for Technicians involves repairs, replacement of parts, use of precision tools, troubleshooting for problems and testing of equipment following repairs to ensure that work has been done properly and within prescribed safety limits. The commercial airlines or smaller facilities require technicians to work on many types of aircraft and perform all phases of the maintenance process. In other larger facilities, technicians may specialize in preventative maintenance and in specific parts of the maintenance process. Technicians are FAA certified requiring hands-on training as well as classroom hours inappropriate programs. Avionics Bench Technicians (Bench Techs) only perform avionics manufacture, troubleshooting, and repair of components and do not require FAA certification..