From Halopedia, the Halo wiki
The Aviator helmet has a pilot-centric HUD integration. This ultrawideband machine interlink gives Spartan-IV pilots unparalleled control over their aircraft. The helmet also has a pressure-stabilized rebreather feed.
For decades the notion of specialized pilot armor for Spartans was thought redundant given MJOLNIR variants were already suited for the rigors. With the segregation of the Spartan-IVs into their own autonomous branch, the need for multiple intra-organizational disciplines materialized. This led to the Aviator variant's creation.
Aviator was manufactured by Hannibal Weapon Systems and tested at WG/Facility 93-00/Kotka. It was built from the ground up and was designed for the operation of GA-TL1 Longswords, FSS-1000 Sabres, F-41 Broadswords, and B-65 Shortsword bombers.
Spartan pilots meeting D3-17 regulations and higher are required to use this armor in Broadsword A/X attack fighter engagements operations to comply with standard asset security protocols and the Budgetary Retention Hearings of 2554.
Because of the increased production of the vehicles the Aviator armor was made for, this variant has become popular among Spartans. It is employed by the Spartan interceptor pilots attached to the security of ANVIL Station.
The GEN3 Aviator helmet is tailored for use by cybernetically augmented aerospace pilots. Among its many special features is a high-bandwidth machine interlink configured to operate seamlessly with next-gen neural interlaces.
Halo 3 MCC - Prototype
In the Halo: The Master Chief Collection version of Halo 3, the Aviator variant was added as part of Series 5: Anvil content. With the updated Halo 3 armor customization options, the players can now fit their Spartan with Aviator helmet, chest, shoulders and legs; the set is one of six to not recieve any associated forearm options. The description of the armor pieces are the same for every set.
Halo 4 - GEN2
Halo 5: Guardians - GEN2
The Aviator returns in Halo 5: Guardians. The helmet and body armor are unlockable as armor permutations through the Requisition system. The body armor includes the Aviator chest and shoulders, GV-09 Locking forearms, and Contoured legs. The Aviator set has three alternate skins: Ace, Delta, and Csar.
Halo Infinite - GEN3
The following attachments are not exclusive to Aviator, and are compatible with other helmets on the Mark VII core.
Halo 5: Guardians skins
List of appearances