PILOT-class Mjolnir

MJOLNIR Powered Assault Armor/Pilot is a MJOLNIR armor-compatible version of the primary helmet used by UNSC Air Force pilots. It was developed by Chalybs Defense Solutions for the Mark IV and Mark V generations and was tested at the Chalybs Testing Preserve.

Overview
The Pilot helmet entered service in 2541 and was eventually adapted for use with all UNSC armor systems. It looks remarkably similar to the MJOLNIR EVA and SPI helmets. While the similarities with the latter are strictly coincidental, the resemblance to the EVA helmet is a byproduct of Chalybs' collaboration with the Ganymede-based branch of the Materials Group, leading to many similarities with the EVA variant's physical architecture.

It was used by the select few SPARTAN-II and SPARTAN-III supersoldiers attached to the Air Force as pilots and combat controllers and meant for engagements in both atmospheric and exoatmospheric conditions. The helmet's primary advantages are its increased field of vision and its aerospace-oriented tactical software suite incorporated to the heads-up display.

Following the establishment of the Spartan branch and the instatement of dedicated Spartan pilots, the Pilot variant was likely replaced by the Aviator-class armor suite.

In 2558 the Pilot helmet is still being used on posters in locations like the Promesa‎ research center on Andesia.

Normal Helmet
Adopted by the UNSC Air Force in 2542, this helmet is compatible with all current armor systems. Base Price: 90,000 cR, Commander HUL[3] Price: 25,000 cR, Commander UA/HUL[3] Price: 55,000 cR, Commander
 * Description: Although it bears some similarities to the SPI helmet, they are purely cosmetic in nature.
 * Description: Third-generation external hardened uplink for MILINT acquisition; required for sensitive OPs.
 * Description: Up-armored variant with hardened 3rd-generation uplink module.

"Haunted" Helmet
"Happy friggin' Halloween!"

- In-game description

Haunted Price: 1 cR, Inheritor, All purchasable Base Helmets in the game

The Haunted Helmet is a variant of the Pilot helmet which has a transparent visor, showing a skull where the face should be. This helmet can be bought for 1 cR, but only after obtaining every other purchasable helmet base and possible permutations. The player needs to have earned at least 1,526,000 cR to purchase the necessary helmets and variants, which the player will inevitably do as they make their way to Inheritor, which is a rank required to obtain the helmet. Because of the rank needed to buy this helmet, the Haunted helmet was (at the time of Halo Reach's release) almost completely exclusive to Bungie employees in much the same way the Recon armor in Halo 3 originally was. It has been obtained by a rising number of players in the four years since the launch of Halo Reach however (enough to garner the semi-derogatory title of "Inheritor Helmet"), and can also be obtained by modding.

Trivia

 * If the Haunted Helmet is worn during the level Noble Actual, one will see the base of a skull in their helmet as they put it on. If it is worn during the final cutscene of Lone Wolf, it will swap models with random helmets in between shots while it lays on the ground.
 * The player's visor color will change the color of the Haunted Helmet's skull.

List of appearances

 * Halo Reach
 * Halo: Combat Evolved Anniversary
 * Halo 5: Guardians