 In the early stages of Naval Aviation, this occupation was performed by Machinist's Mates with an aviation specialty, but qualifying for the aviation specialty required meeting the standards for the general rating as well as those required for the aviation specialty.The Aviation Machinist's Mate rating was established on July 1, 1921, along with Aviation Metalsmith, Aviation Carpenter's Mate, and Aviation Rigger.These were the first ratings used specifically for aviation and based solely on aviation requirements.