Su-35 Flanker-E: Russia’s Most Feared Fighter Jet Explained

The Su-35 Flanker-E stands as one of the most capable and closely watched combat aircraft flying today. Built by Sukhoi, the Russian aerospace company behind some of the Cold War’s most iconic warplanes, the Su-35 pushes the original Su-27 design to its absolute limits. Equipped with thrust-vectoring engines, a long-range passive radar, and a weapons payload that covers nearly every combat scenario, this aircraft sits at the peak of what’s known as generation 4++ — a tier above conventional 4th-generation jets but short of true 5th-generation stealth fighters. For defense analysts and military enthusiasts alike, understanding the Su-35 is essential to understanding modern air power.

From Cold War Blueprint to Modern Warplane

The Su-27 Legacy: Where It All Began

To understand the Su-35, you have to go back to the late 1970s. The Soviet Union needed a heavy air superiority fighter capable of matching the newly introduced American F-15 Eagle. The answer was the Su-27 Flanker — a large, agile, long-range fighter that became one of the most successful Soviet aircraft ever built. It was fast, maneuverable, and packed serious range. But as technology moved forward, Sukhoi engineers knew the platform could go much further.

Work on a significantly upgraded version began in the late 1980s, under the internal designation Su-27M. The project evolved substantially over the following two decades, with multiple demonstrators and redesigns before the program reached maturity. By the early 2000s, the aircraft had been largely rebuilt from the inside out.

The Su-35S: From Prototype to Front-Line Fighter

The definitive production variant, designated Su-35S, was officially accepted into Russian Air Force service in 2014. The “S” stands for Stroyevoy — Russian for “combat-ready” or “operational.” Earlier demonstrators like the Su-35BM were never mass-produced; they existed primarily to test systems and technologies that eventually found their way into the Su-35S. Total production estimates range between 130 and 151 airframes, depending on the source, with the Russian Air Force holding the vast majority.

Avionics, Sensors, and Electronic Architecture

Irbis-E Radar: Built to Find You First

The Su-35’s primary sensor is the Irbis-E, a passive electronically scanned array (PESA) radar developed by Russia’s Tikhomirov NIIP institute. It can track up to 24 targets simultaneously at ranges exceeding 100 kilometers over complex terrain. By any measure, it is a highly capable radar — though Western analysts consistently note that it lags behind modern active electronically scanned array (AESA) systems like those found in the F-15EX and F-22. The distinction matters: AESA radars are harder to jam, faster to reposition, and generally more resistant to electronic countermeasures.

In addition to the nose-mounted radar, the Su-35 retains a rear-facing radar unit housed in its distinctive tail “sting” — a design inherited from the Su-27 — giving pilots a level of rear-sector situational awareness that most Western fighters simply don’t have.

OLS-35: Hunting Without Emitting

One of the Su-35’s most tactically valuable tools is the OLS-35 infrared search and track (IRST) system. It detects heat signatures from other aircraft — engine exhaust, aerodynamic heating, even solar reflection off airframes — without emitting any radar signal. That means the Su-35 can build a targeting picture on an adversary while remaining electronically silent, giving away nothing to radar-warning receivers. Western air forces have taken note, and several nations have responded by developing their own IRST pods for 4th-generation platforms.

Khibiny Electronic Warfare Suite

The Khibiny electronic warfare system is rarely the headline feature in discussions about the Su-35, but it may be one of its most strategically significant assets. Designed to disrupt the guidance systems of incoming missiles, Khibiny can degrade the effectiveness of radar-guided weapons — including, according to some analyses, the AIM-120 AMRAAM, the standard beyond-visual-range missile used across NATO air forces. The system has been widely discussed in Western defense circles, particularly following Russian operations in Syria.

Thrust-Vectoring Engines: Rewriting the Rules of Agility

Powered by two Saturn AL-41F1S turbofan engines, each producing around 32,000 lbf of thrust in full afterburner, the Su-35 has a thrust-to-weight ratio that exceeds 1.0 — meaning it can accelerate vertically from a standstill. But what truly sets it apart is three-dimensional thrust vectoring: the exhaust nozzles can swivel in any direction, allowing the aircraft to redirect its thrust independently of its flight path.

The result is an aircraft capable of post-stall maneuvers that defy conventional aerodynamics — tight nose-pointing at near-zero airspeed, rapid direction reversals, and sustained high-angle-of-attack flight. These capabilities are particularly dangerous in short-range dogfights, where pointing the nose at a target before the enemy can react is often decisive.

The cockpit reflects the aircraft’s modern pedigree. Multi-function color displays, a wide-angle HUD, and a quadruple-redundant fly-by-wire flight control system give pilots both the information and the control authority they need at any point in the flight envelope.