TM 1-1520-264-23
a.
Place probe on a good area in the inspection location and null. Adjust phase as required to obtain horizontal
lift-off.
b.
Inspect the part.
c.
Any signal similar to the notches in the test block is cause for rejection.
NOTE
Either probe identified in paragraph 3.7.3.1 may be used depending primarily on the ease of accessibility
and user friendliness. If the probes are changed, steps 3.7.3.5 b. (1), (2), and (3) shall be repeated each
time a change is made.
3.7.3.7
Marking and Recording of Inspection Results. Mark and record the inspection results as required by paragraph
1.3.
3.7.4
Backup Method. Fluorescent Penetrant, refer to paragraph 1.4.7.
3.7.5
System Securing. The forward hanger bearing support, if removed, requires installation in accordance with the
applicable technical manuals listed in Table 1-1.
3.8 AFT HANGER BEARING FLANGE (MT).
3.8.1
Description (Figure 3-1. Index No. 8). The aft hanger bearing flange connects drive shaft 4 and 5. The aft
hanger bearing assembly supports and aligns drive shafts 4 and 5.
3.8.2
Defects. This inspection is used to verify crack indications found visually on the aft hanger bearing flange. No
cracks are allowed.
3.8.3
Primary Method. Magnetic Particle.
3.8.3.1
NDI Equipment and Materials. (Refer to Appendix B.)
a.
Magnetic Particle Inspection Probe/Yoke
b.
Magnetometer
c.
Black Light
d.
Fluorescent Magnetic Particles, refer to Table 1-8
e.
Consumable Materials, refer to Table 1-8
f.
Aircraft Marking Pencil, refer to Table 1-8
3.8.3.2
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 applicable positions of this procedure. If required, the drive shaft shall be removed in accordance
with the applicable technical manuals listed in Table 1-1.
3.8.3.3
Access. Access is through the tail rotor drive shaft fairing (Figure 1-4, Item R410).
3.8.3.4
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
3-17
