A1C is the abbreviation for the rank of Airman First Class in the United States Air Force. An A1C is an enlisted airman in the pay grade of E-3. This is the third rank in the enlisted tier. Promotion to A1C is usually received after completion of Basic Military Training and Technical Training, however, some select recruits may come into the Air Force as an E-3 if they have college credits or an Associate's Degree.
An A1C is usually new to their duty section and is receiving hands-on training in their chosen career field. As a result, they don't have a lot of extra duties or assignments outside of their everyday job. An A1C has a skill level of "3" in their career field and is working on upgrading to a skill level of "5" so they can take on more responsibility and further themselves in their career.