Moscow delivered its first batch of Su-57s in 2026. The fleet is back in action, but the real fifth-generation engine is still in the testing phase.
Summary
In early February 2026, Russia delivered its first annual batch of Su-57 Felons to the Russian Aerospace Forces. According to Rostec and UAC, the aircraft received feature a new technical configuration, with updated onboard systems and weaponry. This marks a visible restart after a confusing and unclear 2025 in terms of deliveries. However, we must be rigorous on the key point of the engine. At this stage, there is nothing in official Russian communications to suggest that the Su-57s delivered in February 2026 are already equipped with the Izdeliye 30 or AL-51F1 engine in operational service. The established fact is different: at the end of December 2025, a test Su-57 flew with a new engine presented as the Izdeliye 177, while the AL-51F1, often associated with the Izdeliye 30, remains shrouded in ambiguity and does not yet appear to be widely used on production aircraft. The real issue is therefore twofold: Moscow is revamping its fleet, but its Su-57 has still not reached the full industrial maturity it has been promising for years.
The first batch of 2026 revives a slowed-down program
On February 9, 2026, Russia announced the delivery of a new batch of Su-57s to the VKS. The official message is sober: the aircraft have received updated onboard systems and a modernized weapons complex. The exact number of aircraft has not been disclosed. This is an important detail, as the lack of transparency on volumes has become one of the program’s defining characteristics. The announcement does not change everything. Above all, it confirms that the production line is still running and that Moscow is keen to show industrial continuity despite sanctions, component constraints, and ramp-up difficulties.
The recent schedule for the Su-57 Felon remains irregular. Aggregated open sources estimate that by early 2026, Russia will have around 30 operational or quasi-operational aircraft, with prototypes excluded or partially included depending on the counting method. Russia’s official long-term goal remains the contract for 76 production aircraft, signed before the war in Ukraine, but the gap between stated ambitions and actual deliveries remains significant.
At the end of 2025, several analyses noted that no clearly documented deliveries had been announced during the year, or only a very small number, which contrasts sharply with the program’s initial objectives.
Frankly speaking, the February 2026 delivery does not prove that the program has emerged from its turbulence. It only proves that Russia refuses to let the Su-57 appear to be a semi-failure. That is an essential difference.
The fifth-generation engine remains the real stumbling block
The most sensitive point in your argument is also the most important: the question of the engine. The oft-repeated narrative is simple and appealing. The new batch of Su-57s has finally received the “true” fifth-generation engine, known as Izdeliye 30 or AL-51F1, which would pave the way for true supercruise. The problem is that this narrative is moving faster than the established facts.
What we know for sure is that a Su-57 flew on December 22, 2025, with a new-generation engine officially designated by the UAC as Izdeliye 177. The Russian announcement refers to the start of flight tests of this engine on the Su-57. It does not say that the engine is already in widespread use on production aircraft, nor that the batch delivered in February 2026 is equipped with it. On the contrary, several analyses point out that Product 30 has been in development for years and that there is still no clear evidence of widespread service entry on the production fleet.
It is also important to avoid confusing the designations. In open sources, Izdeliye 30, AL-51F1, and now Izdeliye 177 often appear in a maze of sometimes contradictory nomenclatures. Some publications present the 177 as a more credible transitional engine in the short term. Others see it as a parallel step, distinct from the long-awaited final engine. The only certainty is this: yes, the Su-57’s propulsion is advancing; no, it has not been demonstrated that the version delivered in February 2026 will already have the final engine that would bring the aircraft to full fifth-generation maturity.
Supercruise remains a promise rather than a certainty
Supercruise refers to the ability to maintain supersonic speed without afterburners. This is an important factor, as it affects range, relative infrared signature, fuel consumption, and reaction time. For a fighter jet designed to compete with the most advanced Western aircraft, this capability is not a marketing luxury. It is one of the criteria for credibility.
On paper, the Su-57’s final engine should enable this leap forward. Specialized sources attribute gains in thrust, mass, and thermal signature to the AL-51F1, with thrust often cited at around 17,000 to 18,000 kilogram-force (kgf) with afterburners, according to open estimates.
But here again, caution is needed. These data are mainly based on indirect communications and specialized analyses, not on documented operational demonstrations on an online fleet. In short, the Su-57 could theoretically finally reach the promised engine standard. It is not yet possible to seriously claim that this has already been achieved on a large scale.
This is the ambiguity of the program. The Su-57 Felon flies, is being delivered, and is even being exported on a small scale according to some Russian announcements, but its propulsion architecture remains partially transitional. A fifth-generation aircraft still waiting for its final engine is not a historical anomaly. But when this transition lasts almost a decade, it becomes an industrial symptom.
The year 2025 exposed the weaknesses of the Russian supply chain
The year 2025 served as a brutal reminder that producing a modern stealth aircraft does not depend solely on political will. It depends on a supply chain capable of sustaining itself over time. Western sanctions have targeted precisely this industrial depth, particularly electronic components, machine tools, specialized materials, and second-tier suppliers.
A RUSI study published at the end of 2025 is particularly illuminating. It describes the vulnerabilities of the Sukhoi complex, emphasizing its dependence on foreign components, imported machinery, and a supply chain that is more fragile than it appears. The report explains that tougher sanctions on second- and third-tier suppliers could further disrupt Russian fighter jet production. This analysis alone does not prove the details of each delay in the Su-57 program, but it does provide the general context: Moscow continues to produce, certainly, but in a more costly, slower, and more vulnerable industrial environment.
Reuters has documented the same phenomenon on a broader spectrum. In 2025, Russia acknowledged that it needed to tax imported electronics more heavily to support its domestic industry, while implicitly admitting the strategic value of the sector for defense. Other investigations have shown that Russia continues to rely on diverted supply chains, via third countries, to obtain dual-use components. This reality does not completely block production. It complicates it, makes it more expensive, and exposes it to repeated bottlenecks.
The Su-57 is making progress despite everything on its mission systems
However, it would be a mistake to reduce the Su-57 to its engine. The batch delivered in February 2026 focuses on modernized onboard systems and weaponry. This is in line with Russia’s recent trajectory: integrating feedback from operational use, improving connectivity, refining avionics, and expanding the range of usable weapons. Several observations on recent aircraft also point to adjustments to missile warning sensors, head-up displays, and certain external equipment.
On this point, Russia is following a classic logic of gradual catch-up. A program that is struggling with one major element, in this case propulsion, can nevertheless make progress on other components: sensors, software, interfaces, electronic warfare, air-to-air or air-to-ground weapons.
This is not enough to transform the Su-57 into a direct equivalent of an F-35 or F-22. But it does help to avoid the relative obsolescence of the first batches.
It should also be remembered that the Russian military does not use the Su-57 in the same way that the United States uses the F-35. The Russian format remains small in volume and probably reserved for specific missions: penetration, remote weapon firing, coordination, tactical testing, technological demonstration, and political pressure. In this logic, even a small, imperfect fleet retains its usefulness.
The fleet is back, but without any spectacular breakthroughs
The real challenge for 2026 is therefore less about technical “revolution” than about picking up the pace. With around 30 aircraft available according to open estimates, Russia is primarily seeking to thicken a core that is still too thin. A fifth-generation aircraft produced in too small numbers carries little weight in the military balance, even if it is technically interesting. The challenge for the Su-57 is no longer just to fly better. It is to roll off the production line in sufficient numbers.
But this is precisely where the problem lies. The contract for 76 aircraft initially aimed for a much clearer horizon. Today, Russia can still achieve this in the long term, but with a prolonged delay and a continuing dependence on interim solutions. The final engine is delayed. Components remain under pressure. Volumes remain low. And official communications willingly maintain the blur between the testing stage and operational deployment.
This does not mean that the program is doomed. It means that it remains unfinished. The February 2026 delivery date is a sign of continuity, not proof of full maturity. It’s less spectacular, but it’s the most solid interpretation.
The program that says more about industrial Russia than about the aircraft itself
Today, the Su-57 Felon tells a story that goes beyond its aeronautical destiny. It shows how far Russia can still maintain a cutting-edge program under pressure, but also where its limits lie. Yes, Moscow retains the capacity to produce, modernize, and deliver stealth fighters. Yes, the program is still moving forward. But no, Russia has not demonstrated that it has already solved the three-part equation that is necessary for a true change of scale: a definitive engine, stabilized electronics, and a credible industrial production rate.
The interesting point for the future lies elsewhere. If Russia succeeds in making the propulsion system reliable and securing its supply chain, the Su-57 could finally emerge from its long industrial adolescence. If it fails, it will remain a prestige aircraft produced in too small numbers to single-handedly redraw the balance of power in the air. On this issue, the question is no longer whether the Felon exists. The question is whether it can become a real fleet.
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