Aerospace Instrument-Making Annotation << Back Ensuring the Quality of Operation of an Aircraft based on Continuous Monitoring of its Service Life using in-kind Strain Gauge Methods Shilin S.A. To ensure the quality of aircraft operation, the possibility of actively monitoring the service life of the center wing of a non-maneuverable aircraft is being considered. In-kind strain gauge methods are used. During service life testing, the elastic-plastic boundary of the structural material is constructed based on the trend in the output electrical voltage of the strain gauge network, which is a consequence of residual deformations occurring in the center wing elements as their service life is exhausted. This tool is used to justify and schedule maintenance and preventive measures to replace the most critical components before they reach accelerated service life, thereby increasing the overall service life of the product. This preventive approach reduces the scope, duration, and labor intensity of inter flight aircraft maintenance. Keywords: aircraft center section, methods of in-kind strain measurement, the most critical structural elements, the elastic-plastic limit of the structural material. DOI: 10.25791/aviakosmos.5.2026.1559 Pp. 49-54.