the damage. After removal of metal, measure
carefully any blade that has a finished depression.
Send blades with depressions exceeding repair
Cuts, scars, scratches, surface cracks, nicks,
limits to overhaul.
etc., are common types of damage. Repair by
First, measure the depth of each damaged area
forming a "saucered out" depression smoothly
with a dial gauge. Raised edges may interfere with
blended into the blade surface. Carefully examine
the setting of the knife edge of the gauge. Using
the area with no less than a three-power magnify-
aluminum oxide paper, remove any raised edges
ing glass. Use the magnifying glass to make certain
adjacent to the damaged area. Set the base of the
the bottom of the damage is completely removed.
gauge parallel to the longitudinal axis of the blade.
Use local etching to be sure there are no cracks
Gouge depth is the difference between the deepest
at the bottom of-the rework. To avoid removing
point in the damaged area and the adjacent blade
excessive metal, make a local etching check at
surface. In a reworked area, it is the difference
regular intervals during the process of removing
Figure 8-16.-Propeller blade damage rework limits.