After three decades of development and numerous delays, the Su-57 Felon combat aircraft is finally produced in small series for the Russian Air Force. Presented as the new stealth aircraft, its absence from the Ukrainian front seems to demonstrate that the Su-57 Felon is not yet fully mature. This article was published on February 2, 2023 in the magazine n° 2815.
Russian Sukhoi Su-57s in Syria but not in Ukraine
The war in Ukraine could have resulted in the presence of Russian combat aircraft and in particular that of the Sukhoi Su-57 or Felon, according to NATO codification. Cautious, the Russians have for the moment kept Felon away from the theater of operations, contrary to what had been done previously during the Russian intervention in Syria. On this occasion and flying to the aid of Bashar el-Assad, who had requested “military aid” from the Russians, the latter sent various aircraft including MiG-31Ks but also Su-57s. In 2018, the Russian Armed Forces announced that it had deployed two Su-57s to Syria, but this deployment was above all a well-thought-out communication operation.
The Russians were then seeking to demonstrate a “combat proven” capability by firing a missile from one of the two planes. In reality, and unlike the Ukrainian theater of operations, the air threat in Syria was almost nil, the deployment was moreover very short, the two Felons were T-50 prototypes and above all, the two aircraft benefited an air-to-air and air-to-ground escort (Su-35 and Su-25). This first deployment was followed by a second in Syria which would have taken place in 2019 but with much less publicity.
A device yet presented as formidable
So far, therefore, the Su-57 is absent from the Ukrainian skies. However, its announced stealth, its multirole capabilities, its maneuverability demonstrated during air shows…ƒ seem to make it a formidable device. It should even be added that this combat aircraft is one of the few to be equipped with two directional infrared countermeasure systems (DIRCM), identified as 101KS-O. These systems greatly reduce the probability for the very numerous Ukrainian MANPADS to destroy a Su-57 in flight.ƒ
But Russia probably does not prefer to run the risk of losing one of its Su-57s above a theater whose anti-aircraft defenses are, on one side as on the other, powerful and numerous. On the other hand, in December 2022, only about ten production Su-57s seemed to have been delivered. The last examples were also referred to by some as Su-57M or Su-57 “ƒsecond stage”, a modernized version, mainly re-engined with two Saturn izdeliye (literally “ƒ product”)ƒ 30 engines. the turbojets are not yet fully developed.
Because following a first test flight announced but which has never really been confirmed, mass production, the launch of which is estimated at 2024, therefore appears to be a utopia for the moment. This delay can partly be explained by the fact that the izdeliye 30 is an AL-41 equipped with a gas generator which has few common elements with the original turbojet, whose design does not is not strictly speaking recent for the latter. The development of the AL-41F stems from a program that dates back to the mid-1980s. That of the Su-57 begins almost thirty years later. Rather than a redesigned version of the Su-57, the Su-57M would, according to some, only be a Su-57 benefiting only from a “simple” re-motorization.
Only from Russian airspace
This situation did not, however, prevent the Russians from having put into service – like the Americans with the F-35; the Su-57 before the start of mass production. From 2012, the Akhtubinsk air base (Astrakhan oblast, Russia) underwent several changes to accommodate the Su-57s. Satellite images will confirm the presence of several prototypes on the site. A satellite image from December 4, 2022 identifies at least five Su-57s on taxiways and parking lots, alongside numerous combat and transport aircraft and even the S-70 Okhotnik-B combat drone demonstrator.
However, according to British intelligence, this base has been used since June 2022 for the projection of Su-57s not far from Ukraine, while nevertheless being located more than 620 km from Ukrainian forces. The Felons are not used on the front line or behind Ukrainian lines but from Russian airspace by being equipped with long-range air-to-air missiles. This doctrine of standoŸff use is a double-edged sword: it makes it possible to prevent a Su-57 from crashing in Ukrainian territory and from leaking the secrets of this combat aircraft to hostile countries while keeping its reputation intact.
From T-50 to Su-57
Conversely, it is also an admission of weakness; so the plane is not able to fly over enemy lines? What are his real combat abilities? A look back at a device whose gestation was both long and complex. In 2001, the Russian Aerospace Forces (VKS, acronym for Vozdushno-Kosmicheskiye Sily) launched the PAK FA project with a view to acquiring a 5th generation multirole aircraft. The objective is to allow the retirement of certain models of combat aircraft that have become obsolete, such as the MiG-29 and Su-27. Their renewal project, initiated at the end of the 1980s but severely delayed by the collapse of the Soviet bloc, resulted in two prototypes between which Russia will have to choose: the E-721 of Mikoyan-Gurevich (MiG) and the T- 50 from Sukhoi.
Two years later, the Russian government chose the T-50 and voted a budget including the development of the device and the construction of five prototypes (T-50-1 to -5). The aircraft is promising: multirole, stealth, high maneuverability, etc. It will also be compared to the American F-22 Raptor, although the latter is more specialized in the acquisition of air superiority. After seven years of development, the first flight took place on January 29, 2010, but the prototypes turned out to be defective. It takes, for example, a year to repair major structural problems on the T-50-1. The Russian government then placed a second order for revised prototypes.
A difficult development
India became involved in the project very early on, with the signing of an agreement in 2010. It allows India to assume 25% of the aircraft’s development burden and should lead to the acquisition of 166 single-seater and 48 two-seater aircraft. But in 2012, the cost of the program soared to $30 billion and the six billion invested by India is no longer enough. In addition, Russia is struggling to ensure its share of development, with in particular the burning of the T-50-5 in June 2014 and the implementation of Western sanctions on the country following its annexation of Crimea in 2014, to the point to envisage a 50/50 sharing of development between the two countries in 2015.
The components of the T-50-6 are then used to repair the T-50-5 (became T-50-5R). The T-50-6-2, the first revised T-50, took off in April 2016. In 2017, the T-50 officially became the Su-57. The prototypes are then tested by the Russian Air Force and accepted a year later. But, behind the scenes, India is growing impatient because it quickly needs good operational planes. The comparison between the theoretical Su-57 and the Rafale, bought in 2016 by India, deals the final blow to the joint program †: † India withdraws from the program in April 2018 and openly reveals its criticisms. The Su-57 is too expensive and poorly designed, its engines are based on old technology and are unreliable, the radar is unsuitable for missions and its avionics are outdated, the quality of industrialization is not of a level allowing to produce the expected stealth aircraft.…
India withdraws from the program
India’s withdrawal, international sanctions and then the crash of the T-50S-1 during its acceptance flight by the Russian Air Force in 2019, further caused a slowdown in the program despite the downward revision of its ambition (disappearance of the two-seater version in particular). The figure of 52 devices targeted in 2020 will never be reached. The second pre-production T-50S is completed in 2020 and an order for 76 Su-57s is ordered by the Kremlin, with the last aircraft delivered no later than 2028. The VKS must therefore wait until 2020 to receive its first T-50S.
The various images and videos available already confirm that the stealth of the Su-57 is not that of Western models. For example, a video from the channel† RT reveals many defects on the wing of the aircraft, such as the presence of a high number of visible screws and nuts. Conversely, the wings of the F-35 use much less thanks to its industrialization and a specially developed glue, while the screws and nuts used are covered with a paint that absorbs the waves of enemy radars.
The issue of non-stealth wings does not seem to have been taken into account. Worse still, the future Su-75 Checkmate derived from the Su-57 and presented as a rival of the F-35 Lightning †II, also has a significant number of visible attachments on the wings, despite a promise of stealth. Moreover, some experts estimate that the Felon would have a radar equivalent surface (SER) ranging from 0.1†m² (at best) to 1†m² (at worst). This figure is disappointing because the Rafale F3R, simply considered discreet, already has a SER of 0.5†m² while the standard† F4 should allow a SER of 0.1†m². By way of comparison, the F-22† Raptor, recognized as totally stealthy, would have an SER of 0.0001†m² and would therefore be 1,000 to 10,000 times more discreet than a Su-57.
Stealth in question, industrial grade issues
That’s not all, the indices are hardly more encouraging on the industrial or quality control level†: †the Felon production lines seem underdeveloped and have not integrated industry 4.0, the need to import semiconductors and equipment of high technological value, a production quality that can be called into question with regard to the rare shared images of the aircraft, etc. A video of the Russian Air Force thus revealed defects during the production of the canopy, undetected in the control process.
Difficulties in the development of the aircraft such as the Russian inability to produce a high-tech device in large series has already forced the Russian Air Force to order other 4th generation aircraft, reducing the number of expected Su-57s. Thus, the Su-30, Su-34 and Su-35 will form the backbone of the Russian Air Force for many years. However, these devices have clearly shown their limits in international competitions, being systematically considered inferior to their Western competitors in South Korea, Brazil or Indonesia. It is even possible that the Chinese 5th generation aircraft will overtake the Su-57, further reducing potential export customers.