TM 1-1520-253-23
a. Select AC on the AC/DC power switch.
b. Place probe/yoke on part in 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. Demagnetize before moving to the next position. Refer to paragraph 2.7.3.8.
f. Repeat steps a. through e. for Position 2.
g. Rotate the probe legs 90 degrees and repeat steps a. through e. for Position 3.
2.7.3.7 Marking and Recording of Inspection Results.
Mark and record the inspection results as necessary per
2.7.3.8 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.
2.7.4 Backup Method. Fluorescent Penetrant, refer to paragraph 1.4.7.
2.7.5 System Securing. Clean the bore liner thoroughly to remove all residual magnetic particle media. Refer to Post
Cleaning and Restoration of Part or Area After NDI, paragraph 1.4.16. The pitch varying shaft requires installation in
accordance with the applicable technical manuals listed in Table 1-1.
2.8.1 Description (Figure 2-1, Index No. 8). The horizontal hinge pin is a hollow steel pin which connects the pitch
varying shaft assembly to the rotary-wing hub assembly.
2.8.2 Defects. Defects may occur anywhere on the surface of the pin. No cracks are allowed.
2.8.3 Primary Method. Magnetic Particle.
2.8.3.1 NDI Equipment and Materials. (Refer to Appendix B.)
a.
Magnetic Particle Inspection Probe/Yoke
b.
Magnetometer
c.
Black Light
d.
Fluorescent Magnetic Particles
e.
Consumable Materials, refer to Table 1-8
f.
Aircraft Marking Pencil, refer to Table 1-8
