Russia Receives Sixth Su-35S Batch in 2025 Amid VKS Fleet Expansion Push

Milivox analysis: Russia’s receipt of a sixth Su-35S batch in 2025 underscores an accelerated push to modernize its tactical airpower amid ongoing operational demands. The delivery reflects sustained production capacity at KnAAZ and signals the Kremlin’s prioritization of high-end air superiority platforms despite sanctions and resource constraints.

Background

The Sukhoi Su-35S (NATO reporting name: Flanker-E) is Russia’s most advanced serially produced multirole fighter currently fielded by the Russian Aerospace Forces (VKS). Developed by Sukhoi under United Aircraft Corporation (UAC), the Su-35S is a heavily upgraded derivative of the Su-27 platform—classified as a 4++ generation fighter with enhanced avionics, thrust-vectoring engines, and extended range capabilities.

According to official statements from Rostec and UAC released in early November 2025, the sixth batch of Su-35S fighters was delivered to the Ministry of Defense by the Komsomolsk-on-Amur Aircraft Plant (KnAAZ), a key production facility within UAC. The number of aircraft per batch is not officially disclosed but typically ranges between four and eight units per delivery cycle based on historical patterns.

Technical Overview

The Su-35S incorporates several major upgrades over its predecessors:

Engines: Two AL-41F1S turbofan engines with thrust vectoring nozzles provide supermaneuverability and approximately 14.5 tons of thrust each.
Radar: Equipped with the Irbis-E passive electronically scanned array (PESA) radar capable of detecting aerial targets at ranges up to 400 km under optimal conditions.
Avionics Suite: Integrated digital fly-by-wire system, advanced electronic warfare suite including L175M Khibiny-M ECM pods (optional), and GLONASS-aided navigation systems.
Weapons Loadout: Up to 8 tonnes across 12 hardpoints; compatible with R-77/RVV-AE beyond visual range missiles, R-73 short-range IR missiles, Kh-series air-to-surface missiles, guided bombs such as KAB-series munitions.

The aircraft lacks stealth shaping but compensates through high maneuverability and sensor fusion. While not a fifth-generation platform like the Su-57 Felon or F-22 Raptor, it remains a formidable adversary in contested airspace environments when paired with competent tactics and integrated IADS support.

Operational or Strategic Context

The continued delivery of new-build Su-35S fighters comes amid sustained Russian air operations over Ukraine and heightened tensions along NATO’s eastern flank. Since February 2022, VKS assets have been heavily engaged in strike coordination roles using standoff munitions while avoiding close-in dogfights due to Ukrainian MANPADS saturation and Western-supplied IADS systems such as NASAMS and IRIS-T SLM.

The replenishment cycle suggests that attrition or wear-and-tear may be driving increased procurement tempo. Open-source intelligence estimates suggest that at least a dozen Su-35s have been lost since early 2022 due to combat attrition or accidents. Furthermore, Russia may be seeking to bolster its long-term deterrence posture against NATO by maintaining high readiness levels within its elite fighter regiments such as those stationed at Lipetsk or Krymsk airbases.

As assessed by Milivox experts, this sixth batch aligns with Russia’s broader strategy to maintain aerospace parity through incremental modernization rather than leapfrogging into full fifth-gen deployment—given ongoing developmental delays with the Su-57 program and limited serial production rates for stealth platforms.

Market or Industry Impact

The sustained production run for domestic consumption also has implications for export potential. The Su-35 has been marketed globally—most notably to China (24 units delivered between 2016–2018) and Egypt (reportedly ordered ~24 units though deliveries remain opaque). However, Western sanctions imposed post-February 2022 have severely constrained Rosoboronexport’s ability to fulfill contracts involving Western components or banking systems.

This domestic focus may reflect both necessity—due to export limitations—and strategic choice. By keeping KnAAZ lines active for VKS needs instead of foreign customers alone, UAC ensures continuity of skilled labor force retention and industrial base sustainability amid global isolation pressures. However, spare parts availability remains an open question given dependence on some foreign microelectronics pre-sanctions era.

Milivox Commentary

The delivery of six batches within less than eleven months suggests that either production has ramped up significantly post-COVID bottlenecks—or that these aircraft were already in late assembly stages prior to final delivery announcements. This cadence is noteworthy given Russia’s broader economic constraints under sanctions pressure from G7 nations targeting defense-industrial supply chains since early 2023.

According to Milivox analysis, while the Su-35S does not represent a paradigm shift in air combat capability compared to stealth-centric fifth-gen platforms fielded by NATO states or China’s J-20A/B variants—it remains an effective force multiplier when integrated into layered Russian IADS constructs supported by A-50U AWACS coverage and S-series SAM batteries.

A key question moving forward will be whether future batches incorporate any avionics upgrades derived from lessons learned over Ukraine—particularly regarding EW survivability against Western-made radars—or whether these are legacy-configured models fulfilling older MOD contracts signed before full-scale war began in February 2022.