From Halopedia, the Halo wiki
The Navigator armor set was first introduced into Halo 3's Master Chief Collection port along with eleven other new armor sets, as part of Season 5: Anvil. It was not available in the Xbox 360 version of Halo 3. The set is one of six sets that does not have any available forearm armor.
The NAVIGATOR armor set was originally created as a useable armor permutation for Halo Online, a cancelled Halo 3-derived multiplayer game developed by Saber Interactive and Innova Systems which was intended to be released exclusively in Russia for the PC. After the game's cancellation in 2016, the armor was one of twelve sets introduced to Halo 3 in The Master Chief Collection as part of the game's fifth season in 2021.
List of appearances