TM 1-1520-264-23
3.6.3.8
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.
3.6.4
Backup Method. Fluorescent Penetrant, refer to paragraph 1.4.7.
3.6.5
System Securing. Clean the forward hanger bearing flange 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 forward hanger
bearing flange requires installation in accordance with the applicable technical manuals listed in Table 1-1.
3.7
FORWARD HANGER BEARING SUPPORT (E).
3.7.1
Description (Figure 3-1. Index No. 7). The forward hanger bearing support is an "A" Frame which supports
the sealed bearing.
3.7.2
Defects. This inspection is used to verify crack indications found visually on the forward hanger bearing
support. No cracks are allowed.
3.7.3
Primary Method. Eddy Current.
3.7.3.1
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, and 0.040 EDM notches)
f.
Teflon Tape, refer to Table 1-8
g.
Aircraft Marking Pencil, refer to Table 1-8
3.7.3.2
Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance. A partial inspection
for cause (visual indications, sites of mechanical damage, corrosion, etc.) may be performed on all exposed surfaces of
the installed part using this procedure. If required, the forward hanger bearing support shall be removed in accordance
with the applicable technical manuals listed in Table 1-1.
3.7.3.3
Access. Access is through the deck area doors and fairing (see Figure 1-4, Items T250, T290, and T325).
3.7.3.4
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
3-15
