TM 1-1520-265-23
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 2.10.3.8.
f.
Repeat steps a. through e. for position 2.
2.10.3.7
Marking and Recording of Inspection Results . Mark and record inspection results as required by
paragraph 1.3.
2.10.3.8
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.
2.10.4
Backup Method. None required.
2.10.5
System Securing. Clean the balance weight bracket 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 balance weight
bracket, if removed, requires installation in accordance with the applicable technical manuals listed in Table 1-1.
2.11 SPINDLE HORN (ET).
2.11.1
Description (Figure 2-1. Index No. 11). The spindle horn is attached to the main rotor spindle and
transmits pitch movement from the rotary swashplate, through the pitch control rod to rotate the spindle, and changes the
blade angle.
2.11.2
Defects. Defects may occur anywhere on the surface of the spindle horn. All areas where rework has been
performed shall be inspected for cracks. No cracks are allowed.
2.11.3
Primary Method. Eddy Current.
2.11.3.1
NDI Equipment and Materials . (Refer to Appendix B.)
a.
Eddy Current Inspection Unit
b.
Probe, straight, shielded surface, 100 KHz-500 KHz
c.
Probe, right angle, shielded surface, 100 KHz-500 KHz, 90° 1/2 inch drop
d.
Cable Assembly
e.
Reference Block, three-notched aluminum (0.008, 0.020, 0.040 EDM notches)
f.
Teflon Tape, refer to Table 1-8
g.
Aircraft Marking Pencil, refer to Table 1-8
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