an extent as to weaken the structure of the liner weldment.  Buckling of the combustion chamber liner can be corrected  by straightening the liner. Moderate buckling and associated  cracks are acceptable in the row of cooling holes. More severe  buckling that produces a pronounced shortening or tilting  of the liner is cause for rejection. Upon completion of the  repairs by welding, the liner should be restored as closely as  possible to its original shape. Clean all carbon deposits from the nozzles by washing with  a cleaning fluid approved by the engine manufacturer and  remove the softened deposits with a soft bristle brush. It  is desirable to have filtered air passing through the nozzle  during the cleaning operation to carry away deposits as they  are loosened. Make sure all parts are clean. Dry the assemblies  with clean, filtered air. Because the spray characteristics of  the nozzle may become impaired, no attempt should be made  to clean the nozzles by scraping with a hard implement or  by rubbing with a wire brush. Inspect each component part  of the fuel nozzle assembly for nicks and burrs. Many fuel  nozzles can be checked by flowing fluid through the nozzle  under pressure and closely checking the flow pattern coming  for the nozzle. The inspection for cracks is very important because cracks are  not normally allowed. Crack detection, when dealing with the  turbine disk and blades, is mostly visual, although structural  inspection techniques can be used, such as penetrant methods  and others to aid in the inspection. Cracks on the disk  necessitate the rejection of the disk and replacement of the  turbine rotor. Slight pitting caused by the impingement of  foreign matter may be blended by stoning and polishing. Turbine blades are usually inspected and cleaned in the  same manner as compressor blades. However, because of  the extreme heat under which the turbine blades operate,  they are more susceptible to damage. Using a strong light  and a magnifying glass, inspect the turbine blades for  stress rupture cracks and deformation of the leading edge.  [Figures 10-64  and  10-65] Stress rupture cracks usually appear as minute hairline  cracks on or across the leading or trailing edge at a right  angle to the edge length. Visible cracks may range in length  from one-sixteenth inch upward. Deformation, caused by  over-temperature, may appear as waviness and/or areas of  varying airfoil thickness along the leading edge. The leading  edge must be straight and of uniform thickness along its  entire length, except for areas repaired by blending. Do not  confuse stress rupture cracks or deformation of the leading  The turbine blade outer shroud should be inspected for air seal  wear. If shroud wear is found, measure the thickness of the  shroud at the worn area. Use a micrometer or another suitable  and accurate measuring device that ensures a good reading  in the bottom of the comparatively narrow wear groove. If  the remaining radial thickness of the shroud is less than that  specified, the stretched blade must be replaced. Typical blade  inspection requirements are indicated in  Figure 10-66 . Blade  edge with foreign material impingement damage or with  blending repairs to the blade. When any stress rupture cracks  or deformation of the leading edges of the first-stage turbine  blades are found, an over-temperature condition must be  suspected. Check the individual blades for stretch and the  turbine disk for hardness and stretch. Blades removed for  a detailed inspection or for a check of turbine disk stretch  must be re-installed in the same slots from which they were  removed. Number the blades prior to removal. Fuel Nozzle and Support Assemblies Turbine Disk Inspection Turbine Blade Inspection Figure 10-64.  Stress rupture cracks.  10-51