|The following is based on Fallout Tactics and some details might contradict canon.|
The Hellion is a powerful, heavily-armed aircraft, located in Buena Vista.
The Hellion is a vertical take-off/land aircraft that can reach air-speeds in excess of four hundred miles per hour. The armory includes five anti-tank bombs, eight air-to-surface missiles, and dual 60mm cannons. The Hellion was to use standard issue JP-5 fuel in order to fly for 8 hours or longer without refueling.
The construction of the Hellion was mandated by the Emergency Pacification Protocol, triggered in cause of detecting a breach of Vault 0's defenses, or foreign troops/dangerous mutations on American soil. The Calculator would commence its assembly after pacifying the immediate area surrounding the Vault. Once completed, it was estimated that the Hellion would increase the Vault's pacification range five times.
The Hellion appears only in Fallout Tactics.