A fifth-generation jet fighter is a jet fighter classification used around the world that encompasses the fighter technologies developed during the first part of the 21st century. As of 2019 these are the most advanced aircraft. 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 airframes, advanced avionics features, and highly integrated computer systems capable of networking with other elements within the battlespace for situation awareness.[1]
As of December 2018, the only combat-ready fifth-generation fighters are the Lockheed Martin F-22 Raptor, which entered service with the United States Air Force in 2005; the Lockheed Martin F-35 Lightning II, which entered service in 2015;[2][3] and the Chengdu J-20, which entered service with the People’s Liberation Army Air Force (PLAAF) in September 2017.[ The Shenyang J-31 had flight testing of the 3.0 revised version in 2017. The Mitsubishi X-2 Shinshin, TAI TFX, and HAL AMCA are in the early stages of development. The Sukhoi Su-57 is slated for delivery to the Russian Air Force in 2019.
All revealed fifth-generation fighters use commercial off-the-shelf main processors to directly control all sensors to form a consolidated view of the battlespace with both onboard and networked sensors, while previous-generation jet fighters used federated systems where each sensor or pod would present its own readings for the pilot to combine in their own mind a view of the battlespace.[63][64][65] The F-22A was physically delivered without synthetic aperture radar (SAR) or situation awareness infra-red search and track. It will gain SAR later through software upgrades.[66] However any flaw in these huge software systems can knock out supposedly unrelated aircraft systems and the complexity of a software defined aircraft can lead to a software crisis with additional costs and delays.[ By the end of 2013 the biggest concern with the F-35 program was software, especially the software required to do data fusion across the many sensors
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