Bits and Pieces Achievement in Halo: The Master Chief Collection

As a cumulative achievement, this can be done across different playthroughs of NMPD HQ. Towards the end of this mission, while defending your position on a skyscraper’s rooftop platform, you’ll be swarmed by Covenant Banshees and the occasional Phantom Drop ship (there’s about 3-5). In order to destroy the Phantoms, jump on the Missile Pod Launchers and fire away at the drop ships. While mounted, the Launchers have unlimited ammo, an increased fire rate, and a targeting system (homing missiles). Thus, destroying the Phantoms as they arrive shouldn’t bee too much of a hassle. 

Take note that on either side of the platform, there’s a mounted Missile Pod Launcher. Depending on which side the Phantoms arrive, you’ll need to switch back and forth between weapons. Once you’ve taken out about 2-3 Phantoms, it’d be wise to revert your checkpoint so that you can get the rest before triggering the end of the mission. If you rather avoid having to run through the first half of this mission, simply load up NMPD HQ's final Rally Point and you'll be placed at the platform fight. Either way, once 5 Phantoms have been destroyed, this achievement will unlock.