RuAviation

The SJ-100 aircraft (registration 97021, serial 97001) is currently undergoing certification flights in Zhukovsky to validate a domestically developed automatic landing system. According to the United Aircraft Corporation (UAC), twelve flights have been completed as part of the final flight test program required for certification by aviation authorities. The system has demonstrated compliance with safety and landing precision standards.

Aircraft 97021 is an experimental platform with a mix of domestic and foreign components. While several avionics and systems are Russian-made, key elements, including the powerplant, are sourced internationally. For example, the SaM146 engines were produced in Rybinsk by UEC-Saturn in cooperation with the French company Safran.

The autopilot/flight control system (AP/FCU) was developed jointly by KRET and the Yakovlev Design Bureau, with flight control algorithms created in collaboration with the Moscow Institute of Electromechanics and Automation (MIEA). The system supports flight director mode for takeoff and fully automatic control for all other phases. It enables ICAO Category IIIB automatic landings, including automatic alignment, descent, touchdown, and centerline tracking.

Initial verification and debugging of the control algorithms were performed on the “Electronic Bird” integration bench (a GosNIIAS project). Engineers at Yakovlev conducted statistical simulations of Category IIIA landings using the “Aircraft-AP” model. The software was tested against simulated failures and abnormal flight conditions.

Over three million simulated landings were performed, incorporating randomized initial conditions and atmospheric disturbances. The system consistently met regulatory requirements for automatic landing performance. Completion of bench testing allowed the transition to flight tests, which began in June 2025 with aircraft 97021 in Zhukovsky.

In 2024, algorithm certification included simulations of SJ-100 landings under ICAO Categories IIIA and IIIB. The AP/FCU algorithms are integrated with the autothrottle system, enabling coordinated automatic operation. In flight director mode, the pilot manually follows indicators for heading, altitude, and speed deviations. In semi-automatic mode, the autopilot manages specific parameters, such as thrust or bank angle, while the pilot manually adjusts other control inputs.