After the cessation of foreign component supplies, a significant part of the MS-21's structure and systems had to be adapted to Russian materials and equipment. The Russian industry had to master the production of composite structures on a scale that had not existed before, explained Andrey Voropaev, test pilot of the Yakovlev Design Bureau.
According to him, after the departure of foreign suppliers, the aircraft industry had to replace materials and build its own production base.
If you look at the aircraft, only the landing gear struts and fuselage are iron. Everything else is composite: fairings, wing, stabilizers, keel. No one in the country had done this on such a scale before, so materials for composite production were purchased abroad.
This refers to the most prominent structural elements: official Yakovlev data indicates that the share of composite materials in the MS-21's design exceeds 30%.
Now the MS-21 is undergoing certification tests in a new configuration. The aircraft is being checked especially thoroughly: for a passenger liner, it is necessary to confirm the safety of a large number of systems and operating modes.
Viktor Gorbachev, head of the Airport association, also urged not to rejoice too much after the first flight of the serial MS-21. According to him, it is still necessary to establish real operation with passengers on board.