The Sukhoi Su-57 program, initially known as PAK FA (Prospective Aeronautical Complex of Front-Line Aviation) with the internal designation T-50, was first undertaken by Sukhoi in 1999 as a fifth-generation successor to legacy Soviet designs. The legendary planemaker was called upon by the Russian Federation as it had nothing to compete with the US Air Force’s F-22 Raptor, which had debuted in 1997.

In the nearly three decades that have followed since the beginning of that program, only a handful of the jets have been produced. Estimates range between 20 and 25 aircraft total, possibly as many as 30. The very first production model was reportedly lost in an accident in 2019. Ukraine claims to have destroyed at least one example in a deep-strike drone attack in 2024.

In the past few months, Russia has made a show of its imminent delivery of the first export models. Despite Western sanctions, which put a chokehold on avionics and other aerospace components, the industry in Russia has continued to receive some parts. That trickle of supplies has kept the industry from grinding to a complete halt.

The Russian Air Force ordered 76 aircraft initially. Rostec and the United Aircraft Corporation are partnered with Sukhoi in the production of the Su-57 “Felon,” as it is called by its North Atlantic Treaty Organization (NATO) reporting name. Let’s dive into this story behind the one and only fifth-generation stealth fighter made by Russia to date.

Late Arrival To The Battlefield

Since the beginning of Russia's invasion of Ukraine in 2022, the primary role of the Su-57 has been as a launch platform for long-range air-to-surface cruise missiles from inside Russian airspace. The standoff weapons it has employed include the Kh-69 and Kh-59 against Ukrainian targets.

The aircraft has not been committed to direct air combat or deep penetration of Ukrainian airspace, which Western intelligence suggests is due to Russian concerns about its real-world stealth capabilities. The significant losses experienced by Russian forces during the invasion have slowed the initially aggressive attack strategy.

Particularly, the losses to air units are acutely damaging, as the Russian domestic Aerospace industry has been unsuccessful in its attempt to renew full-scale production under the strain of Western sanctions for components and materials that it cannot produce for itself since the fall of the Soviet Union.

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Russia is simply running out of combat-capable airframes. The country's air force cannot continue to withstand battlefield losses before it reaches a critical point where its tactical power collapses completely. Since the Felon is its premier warplane, even a single loss represents a major degradation of the force's overall strength.

It has been reported recently that formations of two or three aircraft have begun to appear closer to the front line, according to Medium. In August of 2025, Military Watch Magazine said the fighters appear to operate as small strike packages with one jet deploying a cruise missile or precision-guided bomb and another jet or two covering the striker.

In March of 2024, Rand published an analysis that estimated the Russian Air Force lost 25% of its total strength in the first two years of the conflict. 19fortyfive.com wrote in January 2025 that the US Air Force estimated closer to 10% losses. At the end of 2024, Ukraine claimed to have shot down 347 aircraft and 325 helicopters; however, those victories were not all verified.

Russia’s Flailing Air Force

Despite Russia's attempt to minimize the exposure of the Su-57 to any risks, Ukraine successfully struck and at least damaged one jet in June 2024. The fighter was parked at the Akhtubinsk airfield in Russia's Astrakhan region, nearly 600 kilometers from the front line, when a Ukrainian drone attacked it.

The Russian Air Force is allegedly using the felon as a test bed for technology like an electronic warfare suite known as the “Himalayas” and a missile-drone hybrid weapon known as the Kh-71K that can execute abrupt evasive maneuvers. Although these novel technologies may represent advances that are slowly bringing the Su-57 to 5th generation standards, it's likely too little too late to make a major difference on the battlefield.

The Felon by itself simply is not enough to change the course of a bill conceived and even more poorly executed military blunder on the scale of this invasion. The aircraft and its weapon systems may well be capable of overcoming Ukraine's recently acquired Lockheed Martin F-16 Fighting Falcon fighters and Soviet-era legacy airframes. Its missiles may even defeat the air defense network, but that is unlikely to result in total victory.

A Catastrophic Conflict

According to the Center for Strategic and International Studies, the Russian military likely hit the 1 million mark in total casualties since the beginning of the invasion sometime in the summer this year. It has been well recorded that the army has conscripted ethnic minorities from all over the Russian territories and even deployed North Korean troops to the front line to supplement their severely mauled forces.

The apparent absence of any kind of modern leadership or strategic doctrine was evident in the beginning days of the war, when high-ranking officers were killed spearheading charges directly into Ukrainian forces. Since then, the Russian military has taken a more conservative tactical approach. However, they have continued to pour Soviet-era military equipment into the conflict as well as soldiers.

The Russian military has not only avoided deploying the Felon to the front line, but given the exceptional success that Ukraine has seen using drones, all of its combat aircraft are rarely deployed to forward areas anymore. Even attack helicopters are now seen using tactics with standoff weapons and hit-and-run tactics.

The Felon’s Long, Painful Birth

Despite research and development efforts beginning in 1997, the first prototype would not take flight until 2010. The aircraft design incorporates an obvious radar-deflecting angular shape as well as a minimized frontal surface area. However, its engines do not appear to incorporate any kind of thermal shielding to mitigate heat signature.

The Kyiv Independent describes the Su-57 as the "worst of the world’s stealth fighters." India had originally partnered to develop the aircraft jointly with Russia in 2007. They dropped out in 2018 as there was no path toward developing a fifth-generation power plant. Viktor Kevliuk, a retired Ukrainian military officer and defense expert, told the Kyiv Independent:

"Overall it's pretty good, but only generation 4+... According to the concept of the fifth-generation aircraft, the engine must be protected from the radiation of radio-electronic equipment, and hide thermal radiation as much as possible, which was not implemented in the Su-57."

Andrii Kharuk, a military historian and weapons expert, also remarked to the Kyiv Independent:

"The aircraft is positioned as a fifth-generation fighter, but until new engines are received, it does not meet one of the fifth-generation criteria – the ability to perform supersonic cruise flight without switching on afterburners… The Su-57 came as a response to the F-22 Raptor, but the US Air Force is already retiring the oldest F-22s, and production of the Su-57 is just beginning.”

A new, second-stage engine, known as the NPO Saturn izdeliye 30 (or AL-51F-1), is allegedly in development to improve performance and finally deliver stealth characteristics. That has yet to materialize on a production aircraft as far as publicly available information reflects. Britannica says that the new engine is designed with 2.5-dimensional thrust vectoring and a flat nozzle shape.

A Hard Sell For The Su-57E

In a campaign that is motivated in equal parts by profit and national pride, Russia has been proactively pursuing sales to long-time customers with other Soviet-era airframes in its inventory, which includes Egypt, India, Iran, and more. So far, the only Air Force to order any aircraft has been Algeria's, which is believed to have purchased ten jets, according to AeroTime.

Russia has proudly displayed the aircraft in many air shows in the eastern geopolitical hemisphere, including a high-profile display at the Zhuhai Air Show and the People's Republic of China (PRC). At the 2024 air show, the aircraft was embarrassingly mocked on social media in China and beyond for its apparently low manufacturing quality.

The two aircraft at the show were the T-50 prototype and a Su-57E export model. The Su-57E export demonstrator has continued to tour since then in an effort to promote sales, but the T-50 has not toured recently. Aside from the first buyer, Algeria, Sukhoi, and Russian defense firms in general have struggled to complete sales. That is at least partially due to restrictions on access to Swift and other banking processes that require Western institutions to complete transactions.

On top of the shaky image of the aircraft's quality and capabilities, it has been rumored that some prospective buyers, like Iran and India, lack confidence in Sukhoi’s ability to deliver the Jets due to the ongoing sanctions that make its supply chain unstable.

After the outbreak of hostilities over the summer between Iran and Israel, it's believed that Iran's Air Force chief went to the PRC in pursuit of a deal for new aircraft. India has rejected both the Su-57 and Lockheed Martin’s F-35 Lightning II for its first 5th-Gen fighter. At this time, it’s unclear what either nation will procure to modernize its fighter fleet.