Jorge Can't Have All the Big Guns Achievement in Halo: The Master Chief Collection

This achievement can be earned on the Easy difficulty (or higher) on Long Night of Solace, Rally Point Charlie.

At the very end of this mission, your primary objective will task you with helping Jorge defend the UNSC Pelican by clearing out the Covenant forces inside the hanger. At any time during this fight, you can actually enter the Pelican yourself and use its chain gun, becoming invulnerable in the process. All you need to do is, while crouched, hug the nose of the Pelican and continuously smash your action button until your Spartan "glitches" into the vehicle. Once you've taken control of the ship's turret, the achievement will unlock.