Category: navion, hartzell, propeller
Applicability: All models equipped with Hartzell propeller blade models 8428, 8428C, 8428R having serial numbers below 61000
Supersedes: n/a
Compliance: Compliance required by April 15, 1948
Procedure: Examine all Model 8428, 8428C, and 8428R blades having Serial Numbers below 61000 in bright daylight or strong artificial light on the front face in the area approximately 4 inches outboard of the blade clamp. Any fillers used in the blade will be discernible to the naked eye. If fillers are found in this area, the paint should be carefully removed and the fillers removed from the blade.
Defects that can be eliminated by removing material to form a shallow saucer not over 1/8 inch at its deepest point, 3/8 inch in width overall, and 1 inch in length overall, should be repaired. Following removal of the defects, the area from which paint has been removed should be repainted and the propeller rebalanced before being returned to service. Blades having defects that cannot be repaired by the above method or by methods described in the applicable portions of CAM 18, should be returned to the propeller manufacturer. The exact location and the extent of rework necessary to remove any defect should be recorded in the log book. Areas having maximum material removed may not have additional material removed for subsequent injuries.
AD-48-06-03