Aviation Combat Element. A Marine Air Ground Task Force. A principal United States Marine Corps organization that combines air-, land-, and sea-borne forces to conduct a wide array of military operations and humanitarian responses anywhere in the world. Comprised of a CE, ACE, GCE, and LCE. May take the form of a MEB, MEF, or MEU. component that contributes the force. Includes all aircraft (fixed- and rotary-wing), their pilots and maintenance personnel, and those units necessary for aviation command and control.