Question: What 5th generation USAF tactical fighter built by Lockheed Martin and Boeing will remain in service alongside the new sixth generation fighter?
Sentence (from "Lockheed Martin F-22 Raptor"): The Lockheed Martin F-22 Raptor is a fifth-generation, single-seat, twin-engine, all-weather stealth tactical fighter aircraft developed for the United States Air Force (USAF).
Relevant evidence: Yes