Senior aircraftman (SAC) or senior aircraftwoman (SACW) was a rank in the Royal Air Force, ranking between leading aircraftman and senior aircraftman technician (SAC(T)) (although SACs in non-technical trades progressed directly to corporal) and having a NATO rank code of OR-2. The rank, which was non-supervisory, was introduced on 1 January 1951. The rank badge was a three-bladed propeller. The rank was renamed Air Specialist (class 1) (AS1) in the Royal Air Force in July 2022.

From March 2005, SACs in technical trades who had attained the Operational Performance Standard were promoted to Senior aircraftman technician SAC Tech and given a new badge of rank, consisting of the three-bladed propeller inside a circle. This new rank was introduced, to distinguish airmen trained to work unsupervised from those who were not, and is equivalent to the old junior technician rank.^{[citation needed]}