side of the dovetail and is leaning in the forwarddirection (fig. 2-12). If a leaner is detected, it must beverified and the engine should be removed from service.Airfoil and Tip Tears.—The most critical area of atorn blade is the area around the end of the tear and itslocation on the airfoil. You should inspect this area forcracks that lead from the tear and are susceptible topropagation. This condition could lead to the loss of theairfoil section that would create downstream impactdamage.You should record all information such asstage, blade locations, area of the blade in which thedefect was found, and the condition of the rest of theairfoil and adjacent airfoils. Section A of figure 2-11shows the nomenclature of a blade.Leading and Trailing Edge Damage.— Randomimpact damage can be caused throughout thecompressor rotor stages by FOD and DOD. The leadingand trailing edge of an airfoil is the area of thecompressor blade extending from the edge into theairfoil. You must assess both sides or faces of the airfoilwhen determining the extent of a given defect. If youobserve a defect, estimate the percentage of damagedchord length. Observe the defect and the condition ofthe airfoil area around the defect. If the observeddamage is assessed to be “object damage,” the mostdifficult determination is the differentiation betweencracks, scratches, and marks made by the passingobjects. Cracks are usually tight in the airfoils, but theapex of the damage usually allows viewing into theairfoil thickness. This provides a direct inspection ofthe area around the crack You may have to use all theprobes at varying light levels to determine the extent ofthe damage.Tip Curl.— Compressor rotor blade tip curl is arandom and infrequent observation. tip curl is usuallythe result of blade rub on the compressor case. Tip curlalso can be the result of objects being thrown to the outercircumferential area of the flow path and then beingimpacted by the rotating blade tip (either leading orFigure 2-12.—Compressor blade leaners.2-11
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