Why Russian fighter jets lack seamless radar-absorbing coatings compared to US jets

American F-35 jets use precise radar-absorbent materials and gap fillers to achieve a seamless exterior, giving them a tiny radar cross-section of 0.001 to 0.005 square metres. In contrast, the Russian Su-57 features visible panel gaps and rivets, raising its radar profile to between 0.1 and 1 square metre. Russian engineers apply these coatings only to key sections to reduce manufacturing complexity.

Russian aviation strategy prioritises extreme speed and manoeuvrability over complete invisibility. The Su-57 achieves a top speed of Mach 2.0 and can supercruise at Mach 1.3 without using fuel-hungry afterburners. The US focuses on remaining unseen, with the F-35 reaching a top speed of Mach 1.6 to destroy targets from long distances.

Applying and maintaining seamless stealth coatings requires immense precision, pushing the F-35's operational cost to roughly $30,000 per flight hour. Russian manufacturers skip these fragile finishes, relying on tough composite materials that require minimal surface care. This strategy helps keep the production cost of an Su-57 between $50 million and $70 million.

Russian military doctrine requires fighter jets to operate from rough, unpaved airfields with minimal infrastructure. Maintaining a delicate, seamless stealth skin at poorly equipped forward bases is practically impossible due to flying debris and a lack of specialized hangars. Instead, the Su-57 features a rugged airframe, allowing frontline ground crews to replace damaged panels quickly.

To compensate for a higher radar profile, the Su-57 uses a multi-array system, including L-band wing radars that offer 270-degree coverage to detect low-observable aircraft. While the F-35 relies on highly advanced sensor fusion to create a comprehensive view of the battlefield, the Russian jet is designed as a defensive interceptor with the kinetic power to counter stealth threats.