What 5th generation USAF tactical fighter built by Lockheed Martin and Boeing will remain in service alongside the new sixth generation fighter?
Sixth-generation jet fighter:  The USAF is pursuing development and acquisition of a sixth-generation fighter through the F-X program to complement existing platforms in service such as the Lockheed Martin F-22 Raptor. Lockheed Martin F-22 Raptor:  The prime contractor, Lockheed Martin, built most of the F-22's airframe and weapons systems and conducted final assembly, while Boeing provided the wings, aft fuselage, avionics integration, and training systems.
i don't know