Sonic Underground (1999)

S1E25 Flying Fortress (Chaos Emerald Crisis, Part 1)

What begins as a relaxing getaway for Sonic, Manic, and Sonia quickly transforms into a fierce struggle to protect Mobius when Robotnik launches his latest creation—the Flying Fortress. Determined to disable the weapon, Sonic attempts to infiltrate the ship, convinced that dismantling its reactor will do the trick. However, his plan backfires, prompting him to seek Knuckles' assistance, as he suspects the power source of the fortress is tied to the Chaos Emerald.