Two-seat Su-57 fighter makes maiden flight

Russia's prototype two-seat Su-57D stealth fighter has completed its maiden flight, fulfilling all planned objectives.

Experts from the United Aircraft Corporation (UAC) have commenced flight testing activities with the two-seat Su-57D stealth fighter. The maiden flight, piloted by test pilot Sergei Bogdan, was successfully completed, meeting all planned objectives, UAC announced today.

The released video shows the Su-57D prototype, bearing tail number "055 Blue", during preparation, takeoff, and landing, supervised by a single-seat Su-57 aircraft. Its vertical stabilizer features an image of the two-seat Su-57 variant, alongside symbols of multiple unmanned combat aerial vehicles (UCAVs) like the S-70 Okhotnik and cruise missiles.

The Su-57D prototype takes off for a test flight in an image released on 20/5. *Photo: UAC*

"Beyond its combat characteristics, the Su-57D can also serve as a combat trainer and a command aircraft," noted Russian Deputy Prime Minister Denis Manturov.

Vadim Badeha, UAC's chief executive, stated that the company continues to refine and expand the Su-57's capabilities. He expressed confidence that the two-seat variant will "significantly contribute to the Su-57's success in the export market".

This announcement comes days after images of the Su-57D undergoing high-speed ground tests emerged. While design graphics of the Su-57D were released by Russian media in 2023, this marks the first appearance of the actual aircraft.

The two-seat Su-57D variant takes off for a test flight in a video released on 20/5. *Video: UAC*

The Su-57D is the world's second fifth-generation fighter with a two-seat version. The first was China's J-20S, which first appeared in photos in 2021.

Thomas Newdick, editor of the US military specialized publication War Zone, believes this fighter variant demonstrates Sukhoi's effort to transform the Su-57 into a command and control platform, facilitating future manned-unmanned teaming (MUT) operations with UCAVs.

"Adding a second crew member can reduce pilot workload during high-intensity missions, particularly those involving unmanned aerial vehicle (UAV) swarm control, electronic warfare, and coordinated strikes. The second pilot would likely control S-70 Okhotnik UAV formations, which Russia has previously tested with the single-seat Su-57," Newdick stated.

Technical specifications of the Su-57D fighter. *Graphic: Izvestia*

According to Newdick, the placement of the rear cockpit on the Su-57D will necessitate modifications to the internal avionics bay, mission systems, and fuel tanks. External shape alterations could also impact the aircraft's stealth capabilities and operational performance.

However, the manufacturer appears to accept these trade-offs to enhance the aircraft's combat effectiveness.

The Su-57 is Russia's first fifth-generation fighter, designed to compete with the US F-22 and F-35, and China's J-20. The Su-57 features radar-absorbing materials and an optimized design for stealth against electronic reconnaissance systems. Each aircraft can carry a total of 6 internal weapons: four in two ventral bays and two missiles in two side bays.

The Sukhoi Corporation began developing the upgraded Su-57M variant after the Russian Ministry of Defense signed a contract for 76 Su-57 fighters in 10/2018. The T-50M prototype underwent flight testing in mid-2022, but the start of mass production remains unclear.

Algeria is the first foreign customer to order the Su-57, with a fleet of 12 aircraft. At least two of these fighters have been delivered and test flown.