Su-57D Two-seat fifth-generation fighter.
The first two-seat prototype of the fifth-generation Su-57D fighter (s/n 055) carried out its
maiden flight on May 19, 2026.
The Su-57D is essentially a modified two-seat version of the Su-57, reportedly developed from the T-50-5R prototype,
which later received the s/n 055.
The second crew member is primarily intended to control accompanying unmanned aerial vehicles (UAVs),
as well as to assist with mission coordination and operational management tasks.
