TM 1-1520-253-23
2.12.3.6 Inspection Procedure. A magnetic field shall be applied to the part perpendicular to-the orientation of possible
cracks. Positions required for this inspection are illustrated in Figure 2-12.
a.
Select AC on the AC/DC power switch.
b.
Place probe/yoke on part at Position 1 as shown.
c.
Press the test switch and apply a light coat of magnetic particle media at the same time. Remove the media
momentarily before removing the current. Current should be applied for no more than five seconds.
d.
Inspect for cracks using the black light.
e.
Premagnetize before moving to the next position. Refer to paragraph 2.13.3.8.
f.
Repeat steps a. through e. for Positions 2 and 3.
2.12.3.7 Marking and Recording of Inspection Results. Mark and record the inspection results as required by paragraph
2.12.3.8 Demagnetization. With the switch remaining in the AC position, place the probe/yoke legs in the same position
used for magnetizing. Press the test switch and withdraw the probe/yoke from the part for a distance of two feet before
releasing the switch.
2.12.5 System Securing. Clean the pitch link thoroughly to remove all residual magnetic particle media. Refer to Post
Cleaning and Restoration of Part or Area After NDI, paragraph 1.4.16. If removed, the pitch link requires installation in
accordance with the applicable technical manuals listed in Table 1-1. Secure the forward and aft transmission work
platform.
2.13 BALL SPHERICAL BEARING (ET).
2.13.1 Description (Figure 2-1. Index No. 13). The ball spherical bearing is a bearing surface for the sleeve bearings of
the stationary swashplate ring assemblies, both forward and aft.
2.13.2 Defects. Defects may occur anywhere on the surface of the spherical bearing. No cracks are allowed.