BNK3R

The BNK3R is an enormously gigantic aircraft with multiple plasma auto cannons, similar to Hyperion wall turrets, but bigger. It also has a main gun that must charge before each shot then fires a laser beam - a gigantic cannon in the center that can deploy below or above the main body.

Critical hit spots
The critical hit spots are the cluster of eyes at the the front and the swivel eye underneath.

Strategy
It has its own life bar, a very large amount of HP, and the battle is not easy because of continuously respawning Loaders and laser grids. The fastest way to defeat it is to shoot at the auto cannons with a strong shock sniper when the BNK3R flies near you.

Alternate Strategy
Alternate method for defeating BNK3R - Once you trigger this boss, run down the ramp to where you zoned in. BNK3R will often fly over and around you, however you will be protected from the majority of attacks due to the ramps above you. Try to take down BNK3R's turrets from a safe spot as that can also cause some damage to BNK3R. Brick will make things a lot easier by sending in Slab Buzzards, which are friendly Bandit Buzzards, to help you in your fight against BNK3R. They are useful as they can literally keep the fire away from you and will respawn an unlimited amount of times should they be destroyed. Occasionally you will have a mob or two of loaders come down to visit every few minutes, however with the friendly Slab Buzzards flying around, they should ignore you and focus solely on the buzzards. You can pretty much kill BNK3R without losing any health should you stay on the rings and away from the central platform. Additionally the ammo vending machine is close by as well. The Slab Buzzards will also drop in health and ammo in case if you are unable to reach the vending machine.

Trivia

 * The number on BNK3R's intro graphic, 00101010, is binary for 42. The number 42 is "The Answer to the Ultimate Question of Life, the Universe, and Everything" in "The Hitchhiker's Guide to the Galaxy" franchise.
 * Sometimes the player may encounter a glitch where BNK3R becomes "stuck" on the upper level of the platform- you can wittle down it's health, however, the BNK3R will not "die", and the level cannot be completed. Should this happen, simply re-load your save or leave the area and return, and the problem should be solved.
 * Killing BNK3R while in fight for you life mode will not grant you a second wind.