Sukhoi Su-35S: Russia’s Fourth-Generation Air Combat Flanker

The Sukhoi Su-35S represents the most advanced and capable evolution of Russia’s famed Flanker family, blending extreme aerodynamic performance with modern sensors, powerful engines and multi-role flexibility. While often described as a “4++ generation” fighter, the Su-35S sits at the very top of non-stealth combat aircraft in service today and remains a cornerstone of the Russian Aerospace Forces (VKS).

The Su-35S traces its lineage to the Su-27, an aircraft originally designed to counter US fourth-generation fighters such as the F-15 and F-16. However, the Su-35S is far more than an upgraded Su-27. It incorporates a redesigned airframe with extensive use of composites, reinforced structures for higher manoeuvre loads, and the removal of canards seen on earlier prototypes to reduce radar cross-section and simplify handling.

Su-27

With an empty weight reduction and improved aerodynamics, the Su-35S delivers exceptional agility, particularly at low speeds and high angles of attack, a hallmark of Sukhoi design philosophy.

At the heart of the Su-35S are two Saturn AL-41F1S engines, each producing approximately 14500 kgf or 32000 pounds of thrust with afterburner. These engines feature three-dimensional thrust-vectoring nozzles, enabling the aircraft to perform dramatic post-stall manoeuvres such as the Pugachev’s Cobra and the Herbst manoeuvre.

While such manoeuvres are often debated in terms of real-world combat value, the thrust-vectoring system provides undeniable advantages in close-range engagements, rapid nose-pointing and energy recovery, especially in within-visual-range (WVR) combat. The engines also give the Su-35S limited supercruise capability, allowing sustained supersonic flight without afterburner under certain conditions.

The Su-35S is equipped with the Irbis-E passive electronically scanned array (PESA) radar, one of the most powerful fighter radars in service. With a quoted detection range of up to 350–400 km against large aerial targets, the Irbis-E enables long-range target tracking and engagement, even in dense electronic warfare environments.

In addition to radar, the aircraft features an advanced infrared search and track (IRST) system, allowing passive detection of airborne targets without emitting radar signals, a valuable capability when facing stealth aircraft or operating in emissions-controlled scenarios.

The cockpit reflects a significant leap forward from earlier Flankers, featuring multifunction displays, hands-on-throttle-and-stick (HOTAS) controls, and improved pilot-vehicle interfaces designed to reduce workload during complex missions.

The Su-35S is a true multi-role fighter, capable of air superiority, strike, and maritime attack missions. It can carry up to 8,000 kg of ordnance across 12 hardpoints. Air-to-air weapons include the long-range R-37M missile, designed to engage high-value targets such as AWACS and tankers, as well as the R-77-1 active radar-guided missile and the highly agile R-73 short-range missile paired with a helmet-mounted sight.

For air-to-ground missions, the Su-35S can deploy a wide array of precision-guided munitions, anti-ship missiles and unguided weapons, making it a flexible platform for both conventional and asymmetric operations.

The Su-35S has seen operational use in Syria and in the Ukraine conflict, where it has been employed in air patrol, escort and strike-support roles. Russian sources credit the aircraft with effective long-range missile employment and strong situational awareness. However, combat operations have also highlighted the realities of modern air warfare, including the growing lethality of surface-to-air missile systems and the importance of integrated air defence networks. Regardless of political context, the Su-35S has provided invaluable real-world data on sensor performance, electronic warfare resilience and tactics in contested environments.

While Russia’s fifth-generation Su-57 remains limited in numbers, the Su-35S continues to serve as the backbone of VKS fighter operations. It also plays a significant role in export strategy, having been delivered to China and Iran and long marketed to other air forces seeking high-end performance without the cost and complexity of stealth aircraft.

Su-57

Serial production of the Su-35S has been centred on the Komsomolsk-on-Amur Aircraft Plant (KnAAZ) in Russia’s Far East, the same facility responsible for earlier Su-27 and Su-30 variants. Deliveries to the Russian Aerospace Forces (VKS) began in 2012, following an initial contract signed in 2009.

To date, approximately 120 Su-35S aircraft have been delivered to the VKS under multiple procurement tranches. These aircraft equip several frontline fighter regiments across Russia’s military districts, including units based in the Western, Southern, Central and Eastern Military Districts, reflecting the type’s role as a nationwide air-superiority platform. The Su-35S has also been regularly deployed forward for air policing, long-range patrols and expeditionary operations.

Production has continued at a steady, if modest, pace, with additional aircraft delivered annually to replace ageing Su-27s and to maintain force levels as Russia’s fifth-generation Su-57 programme matures more slowly than originally planned. As a result, the Su-35S remains the most capable and numerous high-end fighter currently in Russian service.

The Su-35S has achieved limited but strategically significant export success. China became the first foreign customer, signing a contract in 2015 for 24 aircraft, all of which were delivered by 2018. The People’s Liberation Army Air Force (PLAAF) operates the Su-35 primarily in an air-superiority and interceptor role, while also using the aircraft to evaluate engines, avionics and long-range missile integration.

More recently, Iran has emerged as a new Su-35S operator. While neither party has officially confirmed exact figures, multiple credible sources indicate that around 24 aircraft have been transferred or allocated to Iran, reportedly originating from airframes originally built for export customers. These deliveries mark a significant upgrade for the Iranian Air Force, which has long relied on ageing US and Soviet-era fighters.

In March 2025, the Algerian Air Force began operating Su-35S "Super Flanker" fighter jets, with units spotted at Oum El Bouaghi Air Base. These aircraft, originally intended for Egypt but cancelled its 2018 order due to the threat of U.S. CAATSA sanctions, allowed Algeria to effectively "jump the queue".

The Sukhoi Su-35S stands as the definitive expression of the Flanker concept: fast, agile, heavily armed and formidable in air combat. While it lacks the low-observable characteristics of fifth-generation fighters, its sensor suite, weapons load and kinematic performance ensure it remains a serious adversary in any modern battlespace.

Despite international sanctions and geopolitical pressures, the Su-35S production line remains active, primarily supporting domestic requirements. With more than a decade of service experience and continued incremental upgrades, the aircraft is expected to remain in frontline Russian service well into the 2030s, forming a critical bridge between legacy fourth-generation fighters and a future force dominated by the Su-57.

Su-57 and Su-35S