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tip curling within a one-half inch square area on the leading edge of the blade tip is usually acceptable if the curling is not sharp. Curling is acceptable on the trailing edge if it does not extend beyond the allowable area. Any sharp bends that may result in cracking or a piece breaking out of the turbine blade is cause for rejection, even though the curl may be within the allowable limits. Each turbine blade should be inspected for cracks. 

## Turbine Blade Replacement Procedure 

Turbine blades are generally replaceable, subject to moment- weight limitations. These limitations are contained in the engine manufacturer’s applicable technical instructions. If visual inspection of the turbine assembly discloses several broke n, cracked, or eroded blades, replacing the entire turbine assembly may be more economical than replacing the damaged blades. [Figure 10-67] 

In the initial buildup of the turbine, a complete set of 54 blades made in coded pairs (two blades having the same c ode  letters) is laid out on a bench in the order of diminishing moment-weight. The code letters, indicating the moment- weight balance in ounces, are marked on the rear face of the fir-tree section of the blade (viewing the blade as installed at final assembly of the engine). The pair of blades having the heaviest moment-weight is numbered 1 and 28; the next heaviest pair of blades is numbered 2 and 29; the third heaviest pair is numbered 3 and 30. This is continued until 

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