Satellite images confirm damage at Russia’s Su-57 plant

Satellite images published Tuesday provide the first visual confirmation that the April 11 fire at Russia’s Komsomolsk-on-Amur Aviation Plant — known as KnAAZ — caused significant structural damage to the workshop responsible for manufacturing the composite airframe components of the Su-57 Felon stealth fighter.

The images, released by the OSINT group Exilenova+, show multiple roof spans of Shop No. 46 collapsed inward, suggesting the internal damage to the facility is far more severe than the absence of any official Russian statement would imply.

The satellite imagery puts a visual face on what had previously been reconstructed only from social media videos and ground-level footage. Several bays of the workshop’s roof have caved in — a pattern of structural failure consistent with an intense, sustained fire rather than a localized incident. KnAAZ, its parent company Sukhoi, the United Aircraft Corporation, and Russian emergency services have issued no official statement about the fire or its aftermath. Moscow’s silence is now being tested against photographic evidence that tells its own story.

Shop No. 46 is not a warehouse or an administrative annex. According to the assessment published by the open-source intelligence community Cyberboroshno, which analyzed Russian military-industrial activity using the available footage and social media posts, the workshop is the dedicated production facility for polymer composite material components used throughout the Su-57 airframe. The workshop specializes in producing polymer composite parts for the Su-57, including about 300 components, around 100 of them large, such as aileron panels, air intakes, flaperons, flooring, and wing tips. Those parts are not interchangeable with metal equivalents and cannot be quickly sourced from an alternative domestic supplier. Losing even partial access to that output directly disrupts Su-57 airframe assembly at its earliest and most critical stage.

Understanding why this matters requires a brief explanation of what makes the Su-57 different from older Russian combat aircraft — and why composite materials are inseparable from the platform’s core purpose. The Felon is Russia’s only fifth-generation stealth fighter, designed to reduce radar visibility and compete with Western aircraft such as the American F-22 and F-35. Achieving low radar cross-section depends on extensive use of polymer composite panels throughout the airframe — materials that are lighter than metal, shaped in geometries that scatter rather than reflect radar energy, and that cannot simply be replaced with aluminum without gutting the aircraft’s stealth characteristics entirely. Shop No. 46 was the only place in Russia where those parts were being produced at scale for the program.

Production inside Shop No. 46 is largely manual, with only partial automation introduced as recently as 2016, including a laser material marking system. That reliance on skilled manual labor and specialized tooling means that even rebuilding the physical structure of the workshop does not automatically restore its manufacturing output — the equipment, tooling, and workforce trained to operate it must also be reconstituted. KnAAZ operates under extensive Western sanctions — the United States sanctioned the plant in March 2022, and the European Union followed with its own designations — making foreign equipment replacement effectively impossible through legal channels. Any machinery destroyed in the fire cannot be legally replaced with Western industrial equipment, pushing Russia toward slower and more expensive domestic alternatives at a moment when the production line can least afford the delay.

The Su-57 program was already struggling to meet its own delivery obligations before this week. A contract signed in 2019 covers 76 airframes to be delivered by 2027–2028, with the Russian Aerospace Forces standing as the sole operator. Unofficial estimates as of late 2025 placed the total number of Su-57s in service at between 20 and 25 aircraft — a fraction of what Moscow originally envisioned for a program that entered flight testing in 2010. The plant delivered just two Su-57 fighter jets to the Russian Armed Forces in 2025. At two aircraft per year, the gap between the contracted 76 airframes and what KnAAZ has actually been able to produce is already enormous, and the 2027–2028 deadline was looking unrealistic even before fire tore through the composite workshop.

The damage to Shop No. 46 also carries consequences beyond the Su-57 line. Workshop No. 46 is a critical part of serial production for both the Su-57 and Su-35S, though damage there affects Su-57 output more, as it relies far more on composite parts. The Su-35S has been one of Russia’s primary tools for replacing Aerospace Forces losses sustained in Ukraine, and any slowdown in that aircraft’s production adds further pressure to an already stretched aviation industrial base. KnAAZ has been operating at full capacity to meet a long-term state defense order announced in 2024, with deliveries scheduled through 2030. A fire that collapses multiple roof spans of a critical workshop does not arrive at a convenient time.

The KnAAZ plant has faced mounting pressure from multiple directions over the past year. In September 2025, Ukraine struck the Skif-M tooling facility in Belgorod — a supplier whose products feed directly into Sukhoi aircraft manufacturing — with domestically produced Flamingo cruise missiles. Satellite imagery confirmed that all four missiles hit the Skif-M facility, with analysts noting that recovery would be lengthy and complex given the damage to the primary production zone. That strike, combined with the April 11 fire at KnAAZ itself, represents a compounding series of blows to the supply chain sustaining Russia’s most advanced fighter program.