Leading aircraftman
（重定向自LACW）
Leading aircraftman (LAC) or leading aircraftwoman (LACW) is a junior rank in some air forces, between aircraftman and senior aircraftman and having a NATO rank code of OR-2. The rank badge is a horizontal two-bladed propeller.
The rank originated in the Royal Air Force, when it was formed in 1918. It replaced the Royal Flying Corps rank of air mechanic 1st class (which wore the same badge). It was only a trade classification until 1 January 1951, when it became a rank, although it is non-supervisory.