We have carried out investigation of the helicopter MI-26T used in industry, construction studies and technical resources to determine the status of the helicopter. We have analyzed the elements of the force helicopter tail of local-controlled helicopter, and found defect in the resource and the safe zone. The obtained test results allowed to identify the critical elements of a helicopter tail sites and resources, and to adjust for the repairs. On the basis of the mathematical model a possible flaw location has been found. The results obtained allow to increase the helicopter MI-26T secure resources, provided the use of the model formulated by the force helicopter tail elements of the repair and strengthening of the planned repairs at the time of the force elements of the planned repairs