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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
~...................................................................... | | LOCATION CHECKED WITH | CONDITION OF | | PROBE | BLADE TOOL | BLADE | ........................................................................ | PWA 75909 | Leading and Trailing Edges | Installed or | | | | Uninstalled | ........................................................................ | PWA 28404 | Leading and Trailing Edges | Uninstalled | | (PWA 75909 OPT) ..................................................... | | Leading Edge Only | Installed | ........................................................................ | PWA 28443 | Trailing Edge Only | Installed | | (PWA 75909 OPT) | | | 2..................…..............................…....................1
 Eddy Current Probe Application Table 604
 (a)  With the PWA75909 or the PWA28404 Probe, move the probe across the leading or trailing edge of the blade. Start at the blade tip and scan the full length of the leading edge. Refer to Table 1.
 NOTE: The speed at which the probe is moved should be
____ sufficiently slow so that the deflection of the meter is clearly different than the normal base indications.
 CAUTION: OBEY THE INSTRUCTIONS WHEN YOU INSTALL THE TRAILING EDGE
_______ PROBE. INCORRECT INSPECTION OF THE BLADE EDGE COULD RESULT.
 (b)  Put the PWA75909 Probe or the PWA28403 Probe on the convex side of the airfoil with the eddy current coil in the lower ear of the probe. Move the probe along the trailing edge of the blade. Start at the blade tip and move the probe along the full length of the trailing edge. Refer to Table 1.
 NOTE: Correct installation of the probe is necessary to
____ inspect the blade root platform as carefully as possible.
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
(c)  
Any spikes which occur is cause for more inspection. Examine this area more carefully to make sure that the spikes are not caused by human error.

 (d)  
Use your fingers to examine for damage on the blade edge.

 (e)  
Small foreign object damage which can be repaired by blending can cause a signal to appear on the meter. This signal can cause a movement of the meter one unit upwards. This will be followed by a movement of the meter down to its original position. Blend this area per AMM 72-31-02/801 and inspect again.

 (f)  
If any one-unit or more movement of the meter occurs in an area which has been blended free of damage, the results should be seen as cracks. 1) Repair the fan blade (AMM 72-31-02/801). 2) If the depth of the crack is more than the limits, keep the

 blade for a possible subsequent repair.
 S 866-068-N00
 (4)  Remove the protective mat from the inlet cowl.
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
SEE A
OUTER PART
OF BLADE
LEADING EDGE
CONCAVE SURFACE
INNER PART
OF BLADE
AIRFOIL ROOT SECTION
1ST-STAGE
(FAN) BLADE
SEE B
BLADE TIP
PART SPAN SHROUD
FRONT AND REAR SHROUD
RADIUS AREA (4 LOCATIONS)

SHROUD TO AIRFOIL RADIUS
(4 LOCATIONS)
MOMENT WEIGHT MARKS
(CONCAVE SIDE)

A
TRAILING EDGE
CONVEX SURFACE
PLATFORM TO AIRFOIL RADIUS
(ALL AROUND BLADE)

PLATFORM AND BLADE ROOT SECTION
PLATFORM SEAL
BLADE AREA NOMENCLATURE
L-A0967
B
Names of 1st-Stage Blade Areas Figure 601
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