RuAviation

Floor panels manufactured from domestically produced polymer composite materials (PCMs) for the MC-21 narrowbody aircraft have successfully completed a full static testing program at the Central Aerohydrodynamic Institute (TsAGI), named after Prof. N.E. Zhukovsky.

The test campaign was conducted on behalf of Yakovlev PJSC, the MC-21 developer, and forms part of a broader import-substitution program aimed at replacing foreign materials and systems across the aircraft structure, TsAGI said in a statement.

Polymer composite materials account for approximately 40% of the MC-21’s structural mass. Transitioning to Russian-made composites required verification of the strength characteristics of key elements of the fuselage load-bearing structure, including passenger cabin floor panels. These components operate under combined load conditions and play an active role in redistributing loads between frames and longitudinal fuselage members.

Prior to the main test phase, TsAGI specialists prepared the test articles by introducing controlled impact damage to selected panels, followed by non-destructive inspection. This approach enabled engineers to assess structural behavior in the presence of localized defects representative of in-service damage. Strain gauges were installed on the panels and supporting structural elements to monitor the stress–strain state during loading.

The test specimens were installed on a full-scale airframe structure. Engineers assembled a dedicated loading system capable of reproducing calculated load cases. Loads were applied in accordance with predefined test programs, while deformation parameters and internal load redistribution were recorded in real time.

Experimental results were compared with outputs from mathematical and finite-element models. This validation confirmed the accuracy of the applied calculation methods and underlying assumptions. Upon completion of the test campaign, the static strength of the import-substituted floor panels made from Russian polymer composite materials was fully confirmed.

The floor panel tests continue a series of structural investigations conducted by TsAGI under the MC-21 import-substitution program. Earlier, the institute completed static and fatigue tests of the vertical tail, using a dedicated test rig equipped with an automated control, data acquisition, and processing system.

In parallel, TsAGI is preparing and conducting tests of other import-substituted airframe components, including the aileron, airbrake, spoiler, doors, flap support beams, and glazing elements. Together, these studies form the experimental basis for substantiating structural strength and service life as the MC-21 transitions to a fully domestic set of materials and systems.