TM 1-1520-253-23
3.11.3.2
Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance and the slider
shaft removed in accordance with the applicable technical manuals listed in Table 1-1.
3.11.3.3
Access. Not applicable.
3.11.3.4
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
3.11.3.5
NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
3.11.3.6
Inspection Procedure. A magnetic field shall be applied to the part perpendicular to the orientation of
possible cracks. Positions for this inspection are illustrated in Figure 3-11.
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 3.11.3.8.
f.
Repeat steps a. through e. for Positions 2 and 3.
