 Until 1966, their duties were performed by both commissioned officer and senior enlisted naval aviation observers (NAO).In 1966, enlisted personnel were removed from naval aviation observer duties but continued to serve in enlisted aircrew roles, while NAO officers received the newly established NFO designation, and the NFO insignia was introduced.NFOs in the US Navy all begin their careers as unrestricted line officers (URL), eligible for command at sea and ashore in the various naval aviation aircraft type/model/series (T/M/S) communities and, at a senior level, in command of carrier air wings and aircraft carriers afloat and functional air wings, naval air stations and other activities ashore.