F-22 Raptor ( Image credits-Wikimedia commons) A fifth-generation jet fighter is a fighter aircraft classification used in the United States and elsewhere encompassing the most advanced jet fighter generation as of 2014 . Fifth-generation aircraft are designed to incorporate numerous technological advances over the fourth generation jet fighter . The exact characteristics of fifth generation jet fighters are controversial and vague, with Lockheed Martin defining them as having all-aspect stealth even when armed, Low Probability of Intercept Radar (LPIR), high-performance air frames, advanced avionics features, and highly integrated computer systems capable of networking with other elements within the theatre of war for situational awareness . [1] The only currently combat-ready fifth-generation fighters are the Lockheed Martin F-22 Raptor , which entered service with the U.S. Air Force in 2005 and the Sukhoi PAK FA being developed for the Russian Air Force