Mission 9 – The Package
Mission starts at 1:51:42
in the walkthrough video below.
We have two miscellaneous achievements to knock out here. The first requires you to keep your Scorpion tank intact throughout the first portion of the mission until you head back inside the base. To do this, simply take your time, and shoot enemies at great distance. If you wind up getting it overly damaged and are concerned, or destroyed, just restart your last checkpoint, and carry on. The campaign video above shows a good route to take to minimize risk to the tank. Doing so will unlock "Tank Beats Everything".
The next isn’t specific to this level, but it is most certainly easiest to get here. You need to hijack a Banshee. When you reach the portion near the end of the level where you’re defending Dr. Halsey’s lab against waves of Covenant with the four stationary turrets that you can activate, head over to Dr. Halsey’s building, and face out. About 45 degrees to your left is a medium-height building. Grab a jetpack off of the side of Halsey’s lab building, and jetpack up onto that one. Now simply wait for a Banshee to make a low fly-by, and jetpack up to it to execute the hijack. Not only does this net you the "Banshees, Fast and Low" achievement, but it will also make this defense portion much easier if you’re good at dogfighting. The key is to switch to the bomb weapon, shoot it at a group of enemies, then do a backflip maneuver, and circle back for another approach. You can also do a mid-air hijack of another Banshee by getting out of your current one near it and holding your hijack button (controller configuration dependent) as you exit.
At mission completion, you’ll unlock the story-related achievement for the mission on normal or higher.