To start this DLC, you will be contacted by Sheldon regarding a Big Stuff situation going on.
This will only occur after
you've finished the mission "A Terrible Reaction" (Act 1, Mission 4) from the main game.
There will be a mission icon on the world map (region Insula Striate) to look for (yellow bull head with wings) with the first mission "Suit Up".
There are 3 missions in this DLC, and completing them all 3 will unlock this achievement.
The missions are:
- Suit Up
- Taking Control (*)
Please note that there's an achievement related to the 2nd mission (defeating the boss) that might be a bit buggy (not unlocking). Not sure if you're able to redo missions - if your achievement didn't pop, completely restart (cold boot) the console and do mission 2 all over again.
As you progress throughout these missions, you will get the Bavarium Wingsuit and the Bavarium Splitter Rifle.
If you've been playing a tremendous time before starting the DLC, the DLC may feel a bit awkward at first since you'll have to look for objects to destroy on almost all sides of the airship.
Hereafter you'll be able to find some visual aid if need to be (may contain spoilers).Mission 1 : Suit Up (+ Airship Takeover)
Mission 2 : Taking Control
Mission 3 : Severance
Credits to TheGamerPlug for posting these videos on youtube.