The Mega-Fortress XJ series is a series of airship utilized by the Warlord.
The first model used is the Flying Mega-Fortress XJ-5 Warlord mentions that with the Mega-Fortress XJ-5, he will succeed where Emperor Pilaf, the Red Ribbon Army, and so many others have failed. This airship is the greatest stronghold ever built on Earth. Goten and Trunks face him on the top of the airship to retrieve the Five-Star Dragon Ball.
Later in the game, the Warlord utilizes a similar airship called Mega-Fortress XJ-6 built by Pod Corporation. Goku, Vegeta, Gohan, Goten or Trunks head to the airship to fight the Warlord one last time and receive the Hercule Exhibit 16 (Collector's Plate).
Both airships are set to detonate after both encounters with the Warlord.