Figure 2-1.—Geometric orientation of the LM2500 GTEThe following section discusses the borescopeprocedures used to inspect the LM2500 GTE. Theinspection procedures and the knowledge gained fromdamage evaluation may also be applied to the borescopeinspection of the Allison 501-K17 GTE.GENERAL INSPECTION PROCEDURESIt is a good engineering practice to review themachinery history of an engine before you conduct aninspection Various component improvement programswill eventuallyy effect all engines in service. A rebuilt ormodified engine may contain improved parts that differfrom the original. An example of this is the first-stagecompressor midspan damper that may have its originalcoating, an improved coating, or a carboloy shoe weldedon at the midspan damper interface. If you review themachinery history, you will discover the status of thoseparts that have been changed or modified.Assuming that the engine history is normal andFOD is not suspected, you should be aware of thefollowing factors when conducting a borescopeinspection:Know your equipment.Locate all inspection areas and ports.Figure 2-2.—Example of radial and axial cracking.2 - 2
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business