Techniques for increasing the life of small jet engine components have been developed. Turbine nozzles have been improved by introducing localized cooling, and by changes in mechanical design. In the bearing area, life has been increased by reduction of axial thrust and vibratory loads, and the total bearing-lubrication system has been improved by changes in sump venting and carbon seal cooling. Rotor vibration problems have been decreased by changes in design assembly and techniques and bearing supports; and the results of vibration on connecting components have been controlled by study and treatment on a system basis. Integration of numerical computation with test results and field experience is presented as a basis for rational life predictions of rotor parts.