Russia has begun testing a two-seat variant of the Su-57 stealth fighter, with images first published by the Fighterbomber Telegram channel.

The aircraft’s designation remains uncertain, with possibilities including Su-57UB, Su-57D, or Su-57ED, and its development appears linked to both Russian requirements and renewed Indian interest.

The Fighterbomber channel, which is closely connected to Russian Aerospace Forces units, released the first image of the twin-seat Su-57 on 16 May 2026, followed by further confirmation of taxi trials.

The cockpit design is visibly larger, with a canopy extended to accommodate a second crew member, resembling the Su-30 Flanker’s configuration.

This marks a significant development, as the Su-57 becomes only the second fifth-generation fighter to feature a twin-seat variant, following China’s J-20S unveiled in 2021.

Speculation surrounds the aircraft’s designation. Fighterbomber suggested names such as Su-57UB, Su-57D, or Su-57ED, though no official confirmation has been provided. The blurred background of the leaked image makes it difficult to verify its location, and identification markings appear to have been deliberately obscured.

Aviation researcher Andreas Rupprecht noted that the aircraft bore the bort number “055 Blue,” previously associated with the T-50-5 prototype, which was damaged by fire in 2014 and later rebuilt as T-50-5R. This raises questions about whether the new twin-seat variant is based on a modified prototype rather than a fresh build.

The two-seat Su-57 concept is not entirely new. It was originally explored under the joint Russian-Indian Fifth Generation Fighter Aircraft (FGFA) program in the 2010s. India’s Hindustan Aeronautics Limited (HAL) was expected to contribute avionics, cockpit displays, and self-defence systems, while Sukhoi handled the remainder.

Although India withdrew from FGFA in 2018 citing concerns over stealth and sensor performance, the Su-57D project may have drawn upon earlier design work from that collaboration. Renewed Indian interest in the Su-57, particularly after declining the US F-35, has revived speculation that New Delhi could consider a customised two-seat variant for training, mission flexibility, and integration with indigenous systems.

The appearance of a two-seat Su-57 also has operational implications. A second crew member could manage complex sensor fusion, electronic warfare, or unmanned wingman coordination, enhancing the aircraft’s role as a command node in future manned-unmanned teaming operations.

This aligns with Russia’s ongoing work on pairing the Su-57 with the S-70 Okhotnik drone, where the fighter acts as a controller while the unmanned system penetrates contested airspace.

The Su-57 twin-seat variant may also serve export ambitions. Algeria, Iran, and Vietnam have all been linked to potential acquisitions of the Su-57, and a two-seat version could appeal to air forces seeking advanced training platforms or enhanced mission versatility.

For India, the option of licensed production and deeper technology transfer remains on the table, with Moscow signalling willingness to share source codes and allow customisation.

At present, the authenticity of the leaked images cannot be fully verified, but multiple sources report them as genuine. The absence of clear markings and the reuse of prototype identifiers suggest that Russia is still in the early testing phase.

Nevertheless, the emergence of a two-seat Su-57 marks a notable milestone in the evolution of fifth-generation fighters, potentially reshaping both Russian and international procurement strategies.

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