In a notable change in military strategy, Russian Su-35S fighter jets have begun conducting airborne radar reconnaissance missions in Ukraine, a task typically assigned to the larger, specialized A-50U airborne early warning and control aircraft.
This information, shared by the Russian aviation-oriented Telegram channel Fighterbomber and sourced from within Russia’s military aviation sector, highlights the shifting dynamics of the ongoing conflict in Ukraine as of April 2025.
This transition occurs as Russia reduces the operations of its A-50U fleet, reportedly due to losses and the necessity of keeping these vital assets further from the front lines. The involvement of the Su-35S in this unconventional capacity raises questions regarding the operational and strategic consequences for Russia’s air campaign and the overall direction of the war.
The Fighterbomber Telegram channel, which has connections to the Russian Aerospace Forces, remarked, “The Su-35S has taken over the role of the A-50, albeit out of necessity, with confidence and vigor. The results are evident in the news.” Although this assertion lacks official validation from the Russian Ministry of Defense, it suggests a practical adaptation driven by urgent needs.
Before the conflict, Russia’s A-50U fleet was estimated to consist of eight aircraft, which have suffered considerable losses. At least one A-50U was destroyed by a Ukrainian SCALP missile in January 2024, and others have been targeted at airfields, leading Moscow to relocate these high-value assets to safer locations.
The Su-35S, a multirole fighter known for its sophisticated radar and combat capabilities, has stepped in as a temporary solution to address the reconnaissance shortfall. This development not only underscores Russia’s resource limitations but also demonstrates its capacity to adapt existing platforms under challenging circumstances.
To grasp the importance of this transformation, it is crucial to analyze the Su-35S and its features comprehensively. The Sukhoi Su-35S, known by NATO as the “Flanker-E,” is a single-seat, twin-engine fighter jet renowned for its supermaneuverability, developed by the Sukhoi Design Bureau and manufactured by the United Aircraft Corporation.
As an advanced variant of the Soviet-era Su-27, the Su-35S is categorized as a 4++ generation fighter, equipped with state-of-the-art avionics, improved maneuverability, and a formidable arsenal. With a length of 71 feet and a wingspan of 50 feet, the aircraft is powered by two Saturn AL-41F1S turbofan engines, each capable of producing 30,900 pounds of thrust with afterburners.
This configuration enables the Su-35S to achieve speeds of Mach 2.25 (approximately 1,500 miles per hour) and operate within a combat radius that exceeds 900 miles. Its supermaneuverability, facilitated by thrust-vectoring nozzles and an advanced fly-by-wire system, positions it as one of the most agile fighters in Russia’s inventory, capable of enduring up to 10 Gs during maneuvers.
Central to the Su-35S’s enhanced capabilities is its Irbis-E radar, a passive electronically scanned array (PESA) system that serves as the foundation of its N035 avionics suite. The Irbis-E can identify airborne targets at distances of up to 400 kilometers (250 miles) and can simultaneously track 30 targets while engaging eight of them.
The jet’s capability to scan beneath the horizon significantly improves its ability to identify ground targets, positioning it as a feasible, albeit limited, alternative to the radar functions of the A-50U. Additionally, the Su-35S is equipped with an infrared search-and-track system for passive targeting and can carry a wide range of payloads, weighing up to 17,600 pounds, which includes R-77 and R-73 air-to-air missiles, precision-guided munitions, and electronic warfare pods.
In contrast to Western aircraft such as the U.S. F-35 Lightning II, which utilizes an active electronically scanned array (AESA) radar and incorporates stealth features, the Su-35S emphasizes sheer performance and firepower rather than low visibility. While the F-35’s radar provides enhanced resolution and resistance to jamming, the long-range detection capabilities of the Irbis-E radar make the Su-35S a powerful asset for reconnaissance and air superiority operations.
Since its introduction in 2014, the Su-35S has played a vital role in Russia’s air operations. It has been actively involved in missions in Syria, executing precision strikes and providing bomber escort, as well as in Ukraine, where it has been utilized for long-range strikes and air patrols.
Its adaptability has established it as a reliable asset for the Russian Aerospace Forces, with around 100 Su-35S aircraft reported to be in service as of early 2025, according to open-source intelligence from Oryx. However, its new function as a radar reconnaissance platform is a novel development.
Unlike the A-50U, which employs the Shmel-M radar for comprehensive 360-degree coverage and manages extensive air operations with a crew of 15, the Su-35S operates as a single-pilot fighter with a more limited radar field of view and reduced endurance.
The A-50U has the capability to remain airborne for extended periods, identifying threats such as cruise missiles and aircraft from distances of up to 600 kilometers. In contrast, the Su-35S, despite its notable range, faces limitations due to fuel constraints and pilot fatigue. This disparity highlights the challenges Russia must address as it adjusts to losses on the battlefield.
Built on the Ilyushin Il-76 airframe, the A-50U is an essential component of Russia’s aerial strategy. It is outfitted with sophisticated radar and infrared technology, functioning as a mobile command center that orchestrates missile strikes, coordinates air defense systems like the S-400, and offers real-time situational awareness.
The potential loss or limited availability of the A-50U poses a significant risk, as seen in Russia’s careful redeployment of these aircraft. The choice to utilize the Su-35S in this capacity indicates a strategic shift, likely motivated by the necessity to maintain situational awareness in contested airspace while minimizing exposure of the remaining A-50Us to Ukrainian air defenses.
Ukraine has enhanced its military capabilities with Western-provided systems such as the Patriot and NASAMS, which have effectively targeted Russian aircraft. In February 2024, Ukrainian forces reported the downing of two Su-35S jets, underscoring the dangers faced by Russian pilots operating close to the front lines.
From an operational perspective, deploying Su-35S jets for radar reconnaissance changes the landscape of Russia’s air operations in Ukraine. These fighters are probably assigned to specific reconnaissance tasks, such as locating Ukrainian aircraft or directing other jets to targets, rather than offering the extensive command and control capabilities of an A-50U.
This transition places additional demands on Su-35S pilots, who are already managing air superiority, ground attack, and escort missions. The increased responsibilities may strain Russia’s pilot resources and lead to accelerated wear on the Su-35S fleet, which has already experienced losses. According to Oryx, at least seven Su-35S jets have been lost since the conflict began in 2022, due to Ukrainian air defenses, friendly fire incidents, or crashes.
The heightened presence of Su-35S jets in contested airspace increases their susceptibility, especially as Ukraine utilizes electronic intelligence and drones to monitor Russian activities. Ukrainian forces may take advantage of this situation by targeting Su-35S jets during their predictable reconnaissance missions, potentially employing long-range missiles or ambush tactics with newly acquired F-16 fighters.
In a broader strategic context, Russia’s military aviation faces significant challenges. The diminishing A-50U fleet highlights a larger problem: Russia’s difficulty in replacing high-value assets due to Western sanctions that limit access to essential components.
The production of new A-50Us, which depend on sophisticated electronics, is a lengthy and expensive endeavor, further complicated by supply chain issues. This stands in stark contrast to NATO’s strong airborne early warning capabilities, as seen in the U.S. E-3 Sentry and the more modern E-7 Wedgetail, both of which provide enhanced endurance and coordination.
For example, the E-3 can monitor hundreds of targets at once and manage complex air operations, a capability that Russia struggles to match with the Su-35S. This difference highlights NATO’s superiority in networked warfare, where integrated sensors and command systems offer a significant advantage.
Nevertheless, Russia’s adaptability shows a level of resilience. By reconfiguring the Su-35S, Moscow is decentralizing its reconnaissance operations, which may lessen its dependence on vulnerable centralized platforms like the A-50U. This strategy reflects historical examples, such as the U.S. Navy’s deployment of F-14 Tomcats equipped with AIM-54 Phoenix missiles for limited air dominance during the Cold War.
Russia’s innovative approach represents a compromise that falls short of fully replicating the capabilities of the A-50U. The Su-35S fighter jet lacks the necessary crew and systems for effective large-scale coordination, which diminishes its performance in complex operations. Additionally, the aircraft’s high operational demands may put pressure on maintenance and logistics, particularly as Russia focuses on producing new Su-35S and Su-57 fighters to recover from losses.
The ongoing conflict in Ukraine has emerged as a proving ground for military innovation, with Russia’s deployment of the Su-35S for reconnaissance serving as an example of adaptation under pressure. In response, Ukraine is bolstering its air capabilities. Alongside F-16s, Kyiv is expected to receive Saab-340 AEW&C aircraft, which will connect with NATO’s Link-16 network to enhance coordination.
These developments indicate an intensifying air conflict, with both sides adjusting to technological and tactical challenges. Ukraine’s ability to exploit weaknesses in Russia’s strategy, such as targeting Su-35S jets during reconnaissance, could alter the dynamics in critical areas of the front.
Looking forward, Russia’s dependence on the Su-35S for radar reconnaissance raises concerns about the viability of its air strategy. Can Moscow sustain this makeshift approach without jeopardizing other essential missions? Will Ukraine take advantage of this shift to disrupt Russian air operations?
The answers hinge on factors beyond the battlefield, including Russia’s industrial capabilities and Ukraine’s access to Western assistance. Currently, the Su-35S’s new function highlights both Russia’s resourcefulness and its limitations, providing insight into the changing landscape of modern warfare. As the conflict continues, the skies over Ukraine will serve as a testing ground for the boundaries of technology, tactics, and resilience.
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