Abstract: This paper presents a combined finite-element algorthm for non-linear analysis in the process of damage of loaded airframe. On account of the peculiar stressed conditions appeav-ing as yielding and/or buckling in thin sheet, an incremental loading method is used. It is necessary in each loading condition to consider the yielding and/or buckling due to prior stress levels that, decrease airframe loaded capability and lead to geometric changs. The me-thed keforms new stiffness matrix and iterates on the basis of initial stress, then calculates the displacement, strain and stress increments under each incremental load.This method has practically been used in some type of helicopter to describe the whole loading process: initial loading--local damage or crippling and its extension--final damage, and to determine the maximum load and critical failure area of the airframes. The numerical calculation and its comparison with test results are very satisfactary.