In addition to the work specified of the aircraft mechanic classification it also includes the following: performing skilled work in those operations such as trouble shooting, individually or with management or professional direction, disassembly, checking, cleaning, repairing, testing, replacing, adjusting, assembling, installing, servicing, taxiing or towing aircraft, fabricating, and/or run-up engines, maintaining the airworthiness of aircraft and all of their components while in service or while undergoing overhaul and/or modification.