Russian airline S7 will start testing the new APD-520 “Leader” aircraft engine during the summer of 2025, according to Russian media.
The APD-520 engine has been developed in-house by S7 Technics, a subsidiary of Russia’s largest private airline, in order to power the “Tango” light aircraft.
This new four-seater, composite-made aircraft has been developed by Spectra Aircraft Design Bureau, which is also part of the S7 group. It will have a weight of 1,200 kg and be able to reach speeds of up to 241 km/h. Its maximum range will be 1,100 km.
The Tango, which had its maiden test flight in September 2024 and is still under development, was originally fitted with a Belgian-made UL Power UL520is engine, but, back in November 2024, it was reported that S7 had decided to replace it with a domestically produced engine.
The new APD-520 engine is similar in performance to the one it replaces. It is an air-cooled, six-cylinder, 5.2-liter engine producing 200 hp and a service life of 1,500 hours between overhauls. Although the final specifications will be confirmed after the completion of the test phase.
Serial production of the ADP-520, which was publicly presented at Russia’s National Aviation Infrastructure Salon in February 2025, is expected to start in 2026, with the production of 30 units being planned for the first year.
The Tango has been designed primarily with the flight training market in mind. It is expected that its primary customer will be the Russian Ministry of Transport, which runs more than half of the country’s flight schools through Russia’s aviation agency and regulator, Rosaviatsia.
According to Russian media reports, up to 250 Tango trainers may be ordered by governmental organizations to replace and supplement foreign made aircraft currently in use, such as the Cessna 172 or the Diamond DA40, for which it has become difficult to source parts and spares due to the sanctions regime currently in place.
In addition to the Tango and APD-520 program, S7 has also been actively involved in import substitution projects aimed at replacing Western-made parts and components for larger airliners. In October 2024, the airline group began the production of jet engine fan blades in Novosibirsk, Siberia, and had also considered building an engine parts factory in Saint Petersburg but the project was suspended in early 2025.
