Jet fighter generations

Jet fighters are often categorized historically in "generations", a term that first appeared in the 1990s, according to the Royal Australian Air Force's Air Power Development Centre Bulletin: "to make sense of the leap-frogging improvements in performance to jet fighter aircraft brought about through major advances in aircraft design, avionics, and weapon systems". and proposes that a "generational shift in jet fighter aircraft occurs when a technological innovation cannot be incorporated into an existing aircraft through upgrades" and retrofits.

Lockheed Martin has applied the term "fifth-generation" for its F-22 and F-35 aircraft, to imply their competition is unable to offer similar levels of performance, a classification debated by Eurofighter, and by Boeing IDS for the bid to replace Canadian Forces jets.Aviation Week's Bill Sweetman noted that Lockheed Martin "labeled the F-35 a “fifth-generation” fighter in 2005, a term it borrowed from Russia in 2004 to describe the F-22", and proposes that the post–Cold War era, low-cost approach of the Saab Gripen should qualify it as a sixth generation jet. This marketing terminology made its way to statements by the Australian politicians.

USAF historian Richard P. Hallion proposed a classification in 1990:

In 2004 the website Aerospaceweb noted that classification by generations, "appears to have first appeared in Russia during the mid-1990s when officials were planning a competitor to the American Joint Strike Fighter" and proposed a classification :

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Wikipedia