(c)  
These repairs must not have less than the limits of the minimum edge thickness in Figure 801.

 (d)  
Compare all of the blend limits to the initial edge contour of the blade. 1) Add together all of the blends in one location.

 NOTE: For an example, the limit for a blend depth is
____ 0.500 inch (12.700 mm) and you make a 0.200 inch
 (5.080 mm) blend. All the repairs that follow cannot be more than 0.300 inch (7.620 mm) at that location.
 (e)  
Add the blends that are directly opposite on the leading and trailing edges. 1) The sum of the depths must not be more than the trailing

 edge blend limit for that location on the blade.

 (f)  
The blends with a maximum depth on the leading and trailing edges must have a minimum separation. 1) This separation is equal to the mean chordal length of the

 blade (Fig. 802).

 (g)  
Do these steps to make an estimate of the depth of the blend. 1) Put a straight edge along the leading or trailing edge of the blade.

 2)  Measure the maximum distance between the straight edge and the blend.

 (h)  
Make sure that all the edges have satisfactorily rounded radii with a smooth surface.

 (i)  
If you blend the surface with a power tool, remove the last

 0.060 inch (1.524 mm) in depth with a hand tool.
 (j)  
Make sure the radial length-to-depth ratio of the blends to the airfoil is in the limits (Fig. 805).

 B.  
Standard Tools and Equipment

 (1)  
File - for blend repair

 (2)  
Stone - Fine, for blend repair and finishing

 C.  
References

 (1)  
AMM 70-31-01/201, Fluorescent Penetrant Inspection

 (2)  
AMM 71-00-00/501, Power Plant

 (3)  
AMM 72-31-02/401, 1st-Stage (Fan) Blade

 (4)  
AMM 72-31-02/601, 1st-Stage (Fan) Blade

 (5)  
IPC 72-31-02 Fig. 5

 D.  
Access

 (1)  
Location Zone
 412 Engine No. 1
 422 Engine No. 2
 432 Engine No. 3
 442 Engine No. 4

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 72-31-02
 ALL  ú ú N02 Page 812 ú Oct 18/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
E.  Procedure
 S 358-016-N00
 (1)  
If the cracks and damage are more than the applicable limits, do a blend repair of the area.

 (a)  
Blend the damage, to the bottom of the damage.

 (b)  
Blend repair the long dents (with a dented center and high edges) and all the damage with a small radius and rough edges on the blade.

 NOTE: Remove only the edges of the damaged area, when the
____ dents are smooth and rounded bottomed.
 (c)  
Before the subsequent seventh flight cycle, do an eddy current inspection (recommended) or a fluorescent penetrant inspection (FPI) (alternative) to check for cracks.

 (d)  
Before the subsequent 121st hour of operation, do an eddy current inspection to check for cracks.

 NOTE: If you did an eddy current inspection before the
____ subsequent seventh flight cycle, you do not need to do another eddy current inspection before the subsequent 121st hour of operation.
 S 258-013-N00
 (2)  Do an eddy current inspection of the damaged area to check for cracks (AMM 72-31-02/601).
 NOTE: The eddy current inspection is recommended compared to
____
 the FPI.

 (a)  If you do not find a crack, blend the area to a depth that is
 0.020 inch (0.508 mm) more than the depth of the damage,
 (b) If you find a crack, make a mark around the crack.
 1)  Blend the area to a depth that is 0.020 inch (0.508 mm) more than the depth of the crack.
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

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 ALL  ú ú N01 Page 813 ú Oct 15/98
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
　
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