One of the key stages in achieving autonomy in the production of MS-21 was the task of import substitution of units and systems for this aircraft. The creation of own composite materials for the wing and plumage of the aircraft was a key point after 2018. This work was one of the most complex and required significant investments in scientific and production development. Thanks to the efforts of domestic research centres, Rosatom State Corporation and industrial enterprises, the production of carbon fibres and bonding resins in Russia was launched.
In April of the current year in the Central Aerohydrodynamic Institute (TsAGI) named after Professor N.E. Zhukovsky the static tests of the MS-21 keel made of Russian technologies and domestic polymer composite materials were completed. The customer of the work was the company PJSC Yakovlev. To organise the tests TsAGI specialists designed and manufactured a stand including mechanical and hydraulic loading systems, automated control system, data collection and processing. In the course of the research the static strength of the keel was confirmed.
At the first stage of the research, TsAGI scientists conducted an initial cycle of life tests, during which 10,000 flights were simulated. The keel withstood them without damage. Next, static strength tests were carried out, during which the keel was subjected to two cases of loading: up to the operational level and at loads 1.5 times higher than the calculated ones. The stress state and deformations of the structure under external influences were determined. The obtained results fully confirmed all the design parameters.
During the experiments, the resource loads corresponded to the operational loads, those that affect the aircraft in normal flight. Static loads were applied in accordance with the maximum design loads. Such loads are not experienced by the aircraft in reality, but it must withstand them. If the unit under study fails to cope with such loading during research, its design is further developed in order to strengthen it.
“As for the MS-21 keel made of domestic composites, it has successfully passed all the strength tests,” noted Viktor Tsygankov, deputy head of the static and thermal strength department for the experiment of FAU “TsAGI”.
The results of the tests will be submitted to PJSC Yakovlev to prepare a certification opinion on the strength of the MS-21 keel. The next stage will include static tests of the stabiliser made of Russian materials, as well as import-substituted floors, doors, gangways, windshields and porthole windows of the aircraft’s passenger cabin.
