Su-27 Flanker vs Su-35 Flanker-E

Sukhoi’s Su-27 and its Su-35 derivative track the evolution of Russian air combat doctrine from late-Cold War interceptor to contemporary multirole strike fighter. The Su-27 entered service in 1984 to counter the F-15, focusing on kinematic performance and dogfighting. Thirty years later, the Su-35 was fielded as a stopgap, layering active sensors, thrust-vectoring, and electronic warfare suites onto the Flanker airframe to survive in sensor-dense airspaces.

Development and Design

The Su-27 airframe integrates a blended wing-body and large leading-edge root extensions to maximize lift and internal fuel volume, allowing a 3,530 km range without external tanks. Its analog fly-by-wire system enabled high-angle-of-attack aerodynamics. The Su-35 retains this outer mold line but replaces the internal architecture. Sukhoi deleted the Su-27's dorsal airbrake, integrated digital fly-by-wire, and upgraded the sensory baseline. The Su-35 swaps the Su-27's legacy N001 radar for the Irbis-E passive electronically scanned array (PESA), transitioning the platform from a ground-controlled interceptor to an autonomous battlespace manager.

Specifications and Performances

While both airframes share a Mach 2.25 to 2.35 top speed class, their mass and thrust profiles diverge. The Su-35 adds 2,100 kg in empty weight (18,400 kg vs the Su-27's 16,300 kg) to support heavier radar arrays and structural reinforcements. To compensate, Sukhoi integrated Saturn AL-41F1S engines. This alters the kinematic baseline:

• The Su-35 generates 27,400 kgf of thrust, an increase over the Su-27’s 15,340 kgf baseline, yielding higher thrust-to-weight margins.
• Payload capacity rises to 8,000 kg across 12 hardpoints, compared to the Su-27's 10 hardpoints.
• The Su-35 maintains a 3,600 km range despite the heavier empty weight, aided by improved engine specific fuel consumption.

Deployment and usage

Post-Cold War, Ethiopian Su-27s scored kills against Eritrean MiG-29s in 1999. In the Russo-Ukrainian War, both sides deploy legacy Su-27s. Ukrainian Flankers operate in low-altitude defensive counter-air and AGM-88 HARM-launching roles, constrained by their reliance on older R-27 semi-active radar missiles. The Su-35 entered combat in Syria in 2016 flying patrols, but its primary operational data comes from Ukraine. Russian Aerospace Forces use the Su-35 for long-range offensive sweeps, firing R-37M and R-77-1 active-radar missiles at Ukrainian aircraft from stand-off distances. However, the Su-35 has suffered documented losses to ground-based air defenses, indicating limitations in its Khibiny electronic warfare suite against layered surface-to-air missile networks. Export momentum for the Su-35 collapsed post-2022; Indonesia and Egypt canceled orders due to CAATSA sanctions and VKS combat attrition data.

Conclusion

The Su-35 has the edge in beyond-visual-range (BVR) engagements and multirole strike capacity. Its Irbis-E PESA radar and R-37M missile integration allow it to dictate engagements from standoff distances. The baseline Su-27 is obsolete in contested airspace; its reliance on semi-active radar missiles forces pilots to illuminate targets until impact, guaranteeing reciprocal vulnerability. The Su-27 retains utility strictly in peacetime air policing or asymmetric theaters devoid of active-radar missiles. Against a peer adversary, the baseline Su-27 is a liability, whereas the Su-35 functions as an effective BVR platform.