Mathematical models creation for calculating dimensional accuracy at the construction stages of an analytical standard using the chain method

The object of research is the process of forming a mathematical model (MM) for calculating accuracy at the stages of construction an analytical standard (AS) using the chain method, the application of which is shown on the example of an aviation object (AO). The analysis of the investigated AO, namely the helicopter stabilizer, was carried out using modern 3D scanners and the creation of its analytical portrait (AP). The problem is to create the most similar AP and compare it with AS, taking into account the results of the calculations. The following results were obtained: the AS was built and the AP of the stabilizer geometry was created, a comparative analysis of the AP and AS was carried out, and the results of the accuracy of the object geometry calculations were obtained. Aerodynamic calculations of stabilizer characteristics were also carried out, analysis of standardized aerodynamic profiles was carried out taking into account the accepted limitations for forming the stabilizer AS. The scientific and practical novelty of the obtained results is as follows: the created MM for calculating the accuracy of the dimensions of the unit contour using the chain method made it possible to estimate the tying errors that occur when using the loft-template method. This made it possible to choose equipment and software for construction the AS stabilizer. The selection of improved values of the object's aerodynamic characteristics made it possible to build an AS based on the standardized NACA 0012 profile. This can be used as an information basis for the organization of small-scale production of the object under study. That is, in general, the process of reverse engineering made it possible to conduct a detailed analysis of sections, aerodynamic characteristics and improve them for the future improved profile. This design approach provides wider opportunities, eliminates intermediate links and maintains high accuracy of object parameters during its manufacture, which is one of the main requirements in aircraft construction.