Fighter jet “generation” is a pretty informal concept. There is no scientific or engineering definition for it. If you were to ask 10 different people, you’ll get 10 different answers that are likely generally similar but different in the details and you can’t claim one is more correct than the others.
I don’t even think the Generation concept was used until somewhat recently with Gen 4 and Gen 5. I rarely ever hear about Generation 3 and practically never Gen 2 or Gen 1.
Perhaps not “quintessential” but these are certainly representative and familiar to many folks:
1st gen > Me 262:
“Generation 1”: Post-WW2 subsonic jets. Only armed with guns (and maybe air-to-air rockets). Might not even incorporate swept wings and while radar has been invented, they were bulky and generally required a separate crew member to operate, so they were only used by “night fighters”.
2nd gen > F-86:
“Generation 2”: Swept wing, early supersonic jets. Might be armed with early air-to-air missiles. Earlier examples might not have radar but the later models often do (hence the difficulty in splitting the generations). Most (but not all) designs have the intake on the nose that leads to the engine. The pilot is seated over the intake.
3rd gen > F-4:
Generation 3: Radar, missiles, Mach 2 (generally). Some even went so far as to forgo guns and rely exclusively on missiles (early versions of the F-4), but this trend was later reversed. The emphasis is often on speed and altitude. The shape also starts to look more modern with intakes on the sides and a sharp nose cone (that houses radar).
4th gen > F-14/F-15:
Generation 4: First computerized fighters. Takes advantage of the microchip for better sensors and onboard computers. Older pilots might grumble about the airplane flying itself and the pilot is just one input out of many.
5th gen > F-22:
That’s the only difference between “Gen 5” and “Gen 4.5/4++/whatever-you-call-it”. In between are the “Gen 4.5” which has computers and sensors originally for Gen 5 fighters (and features like data link) but are still Gen 4 airframes like F-15 or Su-27.
Generation 5 is the odd one because there’s a “clean break” of “before vs after”, probably last seen in 1940s with the first jet fighters. If there’s any objective dividing line, it’s there. While you could adapt older jets to be semi-stealthy, they’re never going to be as good as a clean-sheet design intended for stealth from Day 1.
(Same story with propeller vs jet airplanes back in the day)
The issue with “Generation” 1–4 is they’re more of a spectrum with no clear dividing line. The fundamental truth about weapons development is that it’s a race: Someone makes something and the other makes a counter. Would the counter be in the same generation as the original airplane?
For example, would the MiG-15 be Generation 1 or Generation 2?
It was subsonic. But it also has swept wings and was capable enough to challenge Allied air superiority in Korea. It readily win fights against straight-wing jets, let alone propeller airplanes from WW2. If that wasn’t bad enough, then consider the MiG-17 that is basically an improvement over the MiG-15. It was still subsonic but remained fairly deadly in Vietnam. Since it had no radar or missiles (at least not initially), it should be with Gen 1 but that’s clearly not quite right too.
So MiG-15 = Gen 1.5 and MiG-17 = Gen 1.75?
This gets rather absurd and convoluted the more you think about it, which is why it’s mainly the domain of historians, the media, and marketing people. Historians might want to make things organized. The media and marketing, they want to sell a story that is easy to understand. Engineers don’t really care about any of these designations.
There are European and Soviet/Russian versions of each generation (except the 5th gen.) But those are less well known to most Quora type folks.
What is the best 5th generation fighter aircraft in the world?
I would say the F-35. Listen, I know the F-22 has no competition when it comes to air-to-air because it’s just so damn stealthy and agile, but the F-35 can do a lot of things that the F-22 can’t. The F-22 is a stealth-air superiority fighter, this means that the F-22 was designed to maintain control of the airspace by using it’s great agility and close-combat capability to eliminate bandits with little ease. The F-35 however, can perform almost every role known to ariel warfare: Air superiority, CAS (close air support), DEAD (destruction of enemy air defences), electronic warfare, striker you name it, it can do it. The F-35 can also operate on an aircraft carrier, this is because there’s the F-35A which is for the air force, F-35B which is for the marines and F-35C which is for the navy, the F-22 only has 1 varient that’s in use, the F-22A. The F-35 can carry 10 missles, that beats every other fifth generation fighter as well. Also I won’t forget to add that the helmet that F-35 pilots wear 400,000 dollar helmets. I think that the F-35 beats the Su-57 and the J-20, because of it’s stealth, manuverability and multirole performence. The F-35 is badass!
