Fighter jets of the newest generation are somewhat of an elite of the world’s air forces. Although the category is very nebulous, and it could be argued that “fifth-generation” is just a marketing label, it is hard to deny the importance of those aircraft.

Stealth, supercruise, LIPR (low-probability-of-intercept radar) and enhanced situational awareness thanks to advanced networking capabilities are usually listed as the defining features of the fifth generation, and each of these features makes them head and shoulders above older jets. Such aircraft are much more capable in both air-to-air and air-to-ground roles than their older counterparts, and rely on much more advanced technologies.

Yet, they carry a price tag to match. Extremely expensive in both procurement and maintenance, fifth-generation fighters will never be employed on the scale that was initially expected from them. Many countries no longer expect to swap their entire fleets of fighter jets for the newest ones, ordering new versions of fourth-generation jets – such as the F-15EX – and aiming to employ fifth-generation ones only as force multipliers. 

Still, all the major air forces are either procuring those jets or have looked into acquiring them. Some, dissatisfied with foreign offers, are in the process of developing their own, new fifth-generation fighter jets, and introducing them in the coming years. 

What are those jets, and which ones of them are going to be the quickest to appear? 

A bit of history

First, just to weed out the projects that are not likely to go anywhere, let’s overview the jets whose development cycle has already ended.

The United States was the first country to develop a fighter jet of the new generation. YF-22 and YF-23 competed in the Advanced Tactical Fighter (ATF) competition in the late 80s and early 90s, which resulted in the Lockheed Martin F-22 Raptor, the first fifth-generation fighter which was adopted in 2005. The YF-23, despite being a fully developed aircraft, never entered production. And despite some rumors that Northrop might offer it to Japan, such a development is highly unlikely.

In the mid-90s the US started the Joint Strike Fighter program to develop a lighter and more flexible counterpart to the F-22, which resulted in X-32 and X-35 prototypes, and eventually – the Lockheed Martin F-35 Lightning II fighter jet. Coming in three distinct variants – A, B and C – it has since been adopted or ordered by numerous countries, including the United Kingdom, Israel, Australia, and a dozen of others. The X-34, meanwhile, turned out to be a much more underdeveloped project, and was dropped by Boeing soon after the contest ended.

China and Russia have been developing their answers to the ATF through the 90s. In 1997, Russia tested the Sukhoi Su-47, and in 2000 – the Mikoyan Project 1.44, both of which are often described as technology demonstrators for fifth-generation fighter jets; none of them were actually adopted, and the first aircraft of the new generation to reach the Russian armed forces was the Sukhoi Su-57, which started deliveries in late 2020. Meanwhile, the Su-47 was turned into a flying laboratory, and the 1.44 – into a museum piece. 

China tested the Chengdu J-20 Mighty Dragon in 2011, and adopted it in 2017. It has also been working on the Shenyang FC-31 Gyrfalcon, a lighter counterpart a prototype of which has been flying at least since 2012, and is rumored to become the country's first carrier-borne stealth fighter.

Japan became the fourth country to test a fifth-generation fighter jet, after the Mitsubishi X-2 Shinshin took off on its maiden flight in 2016. It was just a technology demonstrator though, paving the way to the F-X sixth-generation fighter jet program which started in earnest in 2019. There is no hope for the X-2 to ever enter production, as it was never intended for such purpose. 

Other attempts

A number of other countries have dabbled in the development of their own stealth fighters. 

In 2013, Iran has announced the completion of IAIO Qaher-313; as the aircraft was unveiled, the international community met it with ridicule: experts noted that the aircraft seems to be made of fiberglass, its cockpit is assembled from old Cessna parts, and the overall shape does not make much aerodynamic sense. So, it is safe to say that we won’t see the Q-313 flying soon.

More serious attempts at developing fifth-generation fighters include Pakistani PAC PF-X, Swedish Flygsystem 2020, Turkish TAI TF-X, Indian HAL AMCA, and Korean KF-X.

Of those, very little is known about the Swedish and Pakistani efforts, and they are unlikely to appear in a material form any time soon – if ever. 

Turkish and Indian programs thus far have produced both mockups and concrete timelines, and seem much more promising. The TF-X is expected to fly by 2025, although this promise was made half a decade ago. Since then, British BAE and Russian Rostec have been attached to the project, although their involvement was dropped rather soon. Nevertheless, the rise of Turkey as a “drone superpower” demonstrated that the country is quite able to develop advanced aircraft on its own, and may very well be on the route of wielding the domestic fighter jet. Yet, this is unlikely to happen within the timeframe that was promised in 2015.

HAL AMCA was featured prominently in the latest upgrade plans of the Indian Air Force. Despite that, Indian officials admit that the aircraft is not expected to enter service before the very end of the decade, and the prototype will fly no earlier than 2025. This timeframe seems a bit more realistic than the one promised by the developers of the TF-X, although there is no guarantee that the Indian program won’t encounter unexpected delays.

The Korean fifth-generation fighter jet has the most transparent development cycle of them all. In early 2021 its name was announced to be KF-21 Boramae. A prototype began assembly in 2020, and its first flight is set to happen in 2022. By 2026, KAI plans to start mass-producing it, and replacing most of the antiquated Republic of Korea Air Force’s F-4s and F-5s by the end of the decade. Indonesia, which has been involved in the development since the beginning, is going to receive the jet as well.

There is a question of whether the Boramae is going to be a fifth-generation jet though. Some experts claim that it qualifies to be defined as such, others mark it as generation 4.5. Judging from the available information, it is going to feature some generation staples such as stealth and networking capability, yet lack others, such as supercruise and an internal weapons bay. 

Whatever the outcome, we will most likely see the KF-21 flying in 2022, and decide which generation it belongs to by then.

So what is the answer?

There is one stealth jet that will most likely begin service before the Boramae though. That jet is the FC-31 Gyrfalcon. Although the aircraft has been flying for almost a decade now, its development never progressed beyond the testing of the prototype, and remained dormant for most of that time.

But then, in 2020, it resurfaced. The jet has been noticed sporting significant improvements, and the international public started speculating that China is preparing it for the carrier service – to rival the American F-35C. Lately, the rumors were almost confirmed, as it was being tested on a mockup aircraft carrier.

There are no hard dates regarding the aircraft, and speculation alone can’t answer the question how soon China is going to start mass-producing the FC-31. One possible date is the launch of one of the upcoming aircraft carriers – either the Type 003 or the Type 004, expected in the coming years. But the country might want to showcase the new jet sooner.

In any case, the Chinese FC-31 is the most likely to become the next operational fifth generation fighter jet, arguably followed by the Korean KF-21. By then, the sixth-generation fighter jet programs, currently running in the US, Europe and Japan, are likely to start yielding prototypes – so, there is a chance that all the other developments may be considered as outdated, and the two jets will become the last ones of their generation