During the initial stages of the May 2025 conflict with Pakistan, known as Operation Sindoor, the Indian Air Force (IAF) demonstrated the extraordinary reach of its Russian-origin S-400 Triumf air defence system.
Under the command of Group Captain Animesh Patni, an S-400 battery successfully neutralised threats at record-breaking ranges.
After shooting down a Pakistan Air Force (PAF) JF-17 Thunder nearly 200 kilometres away on the conflict's first night (May 7), the crew turned their attention to a far more strategic prize operating deep within enemy airspace.
Relying on the system's sophisticated 91N6E "Big Bird" radar—which can scan hundreds of kilometres across the border—the Indian crew monitored PAF movements in real time.
Over a 48-hour period, they observed repeated enemy strike formations.
These missions involved PAF JF-17s launching Chinese-made CM-400AKG supersonic stand-off missiles. Their targets included the strategic IAF base at Adampur in Punjab, as well as the S-400 battery itself.
However, the radar also picked up a crucial High Value Target (HVT) coordinating these attacks from a safer distance further west.
Continuous tracking confirmed the HVT was a Saab 2000 Erieye Airborne Early Warning and Control (AEW&C) aircraft.
Procured from Sweden, the Erieye serves as the "eyes in the sky" for the PAF, using its powerful radar to direct fighter jets and manage strike missions.
This made it a vital target for the IAF to disrupt. Despite the S-400's capability to hit the aircraft, the crew had to hold their fire for two days.
Various tactical barriers—such as the target's depth within enemy territory, airspace clutter, and unfavourable missile trajectory angles—prevented a clear shot.
The tactical situation finally shifted on the conflict's last day. The Saab 2000 ventured about 300 kilometres away from the Indian S-400 position. This time, all necessary conditions, from tracking coordinates to the engagement envelope, aligned perfectly.
Upon receiving the green light, Group Captain Patni's unit fired the 40N6E—the S-400's premier ultra-long-range interceptor missile, specifically designed to take down support aircraft like AEW&Cs at distances up to 400 kilometres.
The 40N6E missile utilises a unique flight path to hit distant targets. Once launched, it climbs sharply into the upper atmosphere to reduce aerodynamic drag, reaching hypersonic speeds.
Instead of flying straight at the target, it arcs in a ballistic trajectory, cruising at speeds between Mach 9 and Mach 12 during its mid-course phase.
Crucially, the missile flies almost entirely silent for several minutes; it glides passively without turning on its own radar, meaning the enemy aircraft's Radar Warning Receivers (RWR) detect no incoming threat.
This stealthy approach gave the Pakistani crew virtually no time to react.
While the missile took roughly 3.5 to 4.5 minutes to cover the 300-kilometre distance, the Saab 2000's sensors only alerted the crew when the missile's onboard radar finally activated during the last 30 to 40 seconds of flight.
Given the slow speed of the twin-turboprop aircraft and the missile's terminal velocity, evasive manoeuvres were practically impossible.
The destruction of such a crucial command and control aircraft at extreme range highlights the game-changing nature of the S-400 system.
By taking out the adversary's airborne coordinator, the IAF effectively shattered the PAF's ability to organise complex strikes.
This encounter during Operation Sindoor demonstrates how modern air defence relies not just on advanced hardware, but on the patience, precision, and tactical timing required to exploit a brief window of opportunity.
