Mission 8 – New Alexandria
Mission starts at 1:26:10
in the walkthrough video below.
An all aerial mission, this one requires you to fly between buildings in a Hornet, disabling beacons within a couple, and protecting an ally evac ship toward the end. You’ll have Banshees attacking you and AA guns on the rooftops shooting at you, as well as all the usual Covenant suspects inside the buildings. Just follow along with your waypoints. If you want, you can take out three AA guns with your hornet early-on as I do in the video, but during the escort portion, you will have to take out several anyway so that achievement is essentially unmissable. Destroying three of them with your hornet will unlock "I Didn’t Train to Be a Pilot".
Completing the mission will earn you your next story-related achievement, "Dust and Echoes".