This one is far and away the most complicated design I have attempted. It actually started off along the lines of the Tiger Moth from Castle in the Sky. You can see traces of that in the design of the main decks and the capsule-like pilot house. But from there it quickly got out of control in terms of size.

The use of redstone here is also technically complicated compared with the others. The wiring for the iron shutters in the Captain's cabin had to access 20 separate pistons without the wiring being exposed to either the cabin interior or the exterior of the balloon. It also had to avoid the other wiring for the cabin doors and a wire dropping down to the vault doors below.

The side nacelles each contain accommodations, auxiliary engines, gun decks, and a set of linked bolt-throwers. The nacelles are sort of divided in half diagonally to maximize space.

The upper balloon contains the captain's cabin, a few other cabins, a treasure vault, and a wide bombing deck. To drop blocks of TNT, place them inside the chute below the single fence block and pull the lever. It should be reasonably hard to blow yourself up.