The paper presents a method for calculating the durability of structure regular zones in view of working stresses and aircraft routine flight profile. Application of the method is advisable at the early design stages. The method is based on the discrete atmospheric turbulence model and dependence model for durability calculation by nominal stresses. Fatigue damage for a routine flight has been determined as the amount of damage due to accidental loads and the damage resulting from enveloping ground-air-ground cycle, naturally repeated during each flight. It has been noted that the consideration of the fatigue curve break point in the low-stress area leads to an increase in the calculated durability by 10-15%. A comparison has been made of the calculated durability values for two airplanes with the experimental data of TsAGI. The correlation is satisfactory enough.