TM 1-1520-264-23
4.12.3.2
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 rotor support mixer assembly shall be removed in
accordance with the applicable technical manuals listed in Table 1-1.
4.12.3.3
Access. Access is through the main transmission access panels (Figure 1-4, Items L200 and R200).
4.12.3.4
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
4.12.3.5
NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
4.12.3.6
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 4-12.
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 4.12.3.8.
f.
Repeat steps a. through e. for position 2.
Figure 4-12. Rotor Support Mixer Assembly and Mounting Surfaces
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