Russia flies rebuilt Su-57 prototype in two-seat configuration

Russia’s United Aircraft Corporation confirmed the new Su-57 prototype’s maiden flight, with test pilot and Hero of Russia Sergei Bogdan at the controls in a sortie described by officials as proceeding normally in accordance with its test plan.

Denis Manturov, Russia’s First Deputy Prime Minister, announced the milestone, describing the aircraft as a platform combining combat capability with the functions of a trainer and an airborne battle management system for coordinating mixed formations of crewed and uncrewed aircraft.

When photographs of the two-seat variant first emerged on May 16, Russian military aviation blogger Ilya Tumanov of the Fighterbomber channel confirmed the aircraft had completed ground taxi runs and noted the final designation remained undecided: “Will it be called Su-57D or Su-57UB, we’ll see. As an option — Su-57ED.” The Telegram channel Voyevoda Veshchayet added at the time that the two-seat modification is “intended primarily for export.” Three days later, the aircraft was airborne.

Military aviation researcher Andreas Rupprecht identified the aircraft as carrying bort number “055 Blue,” the same number previously assigned to the fifth flying Su-57 prototype, T-50-5, which was severely damaged by an engine fire on the runway at Zhukovsky in 2014, reportedly in full view of an Indian delegation, and subsequently rebuilt as T-50-5R. That bort number strongly suggests Russia produced the two-seater by taking an existing prototype airframe that had already participated in the Su-57 flight test program and restructuring its forward fuselage to accommodate a second crew member, rather than investing in a clean-sheet design.

The cockpit arrangement closely resembles the tandem configuration of the Su-30 family, with the rear seat positioned significantly higher than the front to give the second crew member adequate forward visibility, a layout that has proven itself across decades of Su-30 operations in more than a dozen air forces worldwide.

Rostec’s first-flight announcement framed the two-seater’s role in language that goes considerably further than a standard combat trainer. According to the state defense conglomerate’s statement, the aircraft “can be used not only for pilot training but also for organizing and managing combat operations of a combined group of manned and unmanned aviation with the formation of a unified information and control space.” That description positions the rear-seat occupant as a dedicated mission commander overseeing drone operations alongside the crewed fighter, a concept the Chinese air force has been developing with the two-seat J-20S since 2021. The new tail logo visible on the prototype, depicting both the Su-57 silhouette and the S-70 Okhotnik stealth drone, visually confirms the pairing Rostec described in words.

The India connection running through this program is difficult to ignore. In 2010, Russia and India signed a contract for preliminary design of the Fifth Generation Fighter Aircraft, a joint program between Sukhoi and Hindustan Aeronautics Limited based on the T-50 prototype, and the Indian Air Force specifically required a two-seat variant of that aircraft. India walked away from the FGFA in 2018 after years of disputes over cost, workshare, and concerns about the aircraft’s stealth performance. The incident in 2014 when the T-50-5 prototype burned on the runway at Zhukovsky with Indian officials watching did nothing to build confidence. Yet the aircraft Russia is now flying bears a striking resemblance to what that abandoned two-seat FGFA would have looked like, and Moscow has spent much of 2026 actively pitching the two-seat Su-57 to New Delhi as a bridge capability while India’s indigenous Advanced Medium Combat Aircraft program works toward a projected first flight in 2029. Russia presented the offer at the Wings India 2026 exhibition in Hyderabad, including full technology transfer and the ability to integrate Indian-origin weapons such as BrahMos and Astra missiles, per Indian defence reporting. India has not indicated whether it will accept.

The single-seat Su-57 fleet that the two-seater builds upon has been growing slowly under sustained pressure from Western sanctions and wartime production demands. As The Defence Blog previously reported, Russia has lost at least four Su-57 aircraft since the full-scale invasion of Ukraine began, with all confirmed losses occurring on the ground as a result of Ukrainian long-range drone strikes against Russian airbases deep inside Russian territory. None of the losses occurred in air-to-air or air defense engagements, raising questions not about the aircraft’s airborne survivability but about Russia’s ability to protect its most advanced combat aircraft from Ukrainian unmanned systems operating hundreds of kilometers inside its territory. The operational export front has been more encouraging for Moscow: Algeria, which signed a contract for 14 Su-57s in 2019, confirmed its first aircraft in early 2026, with photographs and video of Algerian-marked Felons operating over Africa appearing in Russian state media in March and April.

The prototype that flew on May 19 is the beginning of a test campaign that typically takes years before a variant reaches export-ready status. Russia has disclosed no production timeline or procurement quantity for the two-seat Su-57. What the first flight confirms is that a program Russia had been marketing to potential customers for years, including to an India that once abandoned exactly this concept, now has a flying aircraft to show — built not with new resources but with an old prototype airframe that survived a fire, was rebuilt, and has now been reshaped into something Russia hopes will reopen doors that slammed shut in 2018.