TM 1-1520-265-234.5.3.2Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance. A partial inspectionfor cause (visual indications, sites of mechanical damage, corrosion, etc.) may be performed on all exposed surfaces ofthe installed part using applicable positions of this procedure. If required, the vibration absorber shall be removed anddisassembled in accordance with the applicable technical manuals listed in Table 1-1.4.5.3.3Access. Location of these parts varies considerably. Refer to Figure 1-4 and Table 1-2 to locate applicableaccess provisions.4.5.3.4Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,paragraph 1.4.4.4.5.3.5NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.4.5.3.64.5.3.6 Inspection Procedure. A magnetic field shall be applied to the part perpendicular to the orientation ofpossible cracks. Typical springs and positions required for this inspection are illustrated in Figure 4-5.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 mediamomentarily 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 4.5.3.8.f.Repeat steps a. through e. for positions 2 and 3.4.5.3.7Marking and Recording of Inspection Results. Mark and record inspection results as required by paragraph1.3.4.5.3.8Demagnetization. With the switch remaining in the AC position, place the probe/yoke legs in the same positionused for magnetizing. Press the test switch and withdraw the probe/yoke from the part for a distance of two feet beforereleasing the switch.4.5.4 BackupMethod. None required.4.5.5 SystemSecuring. Clean the spring thoroughly to remove all residual magnetic particle media. Refer to PostCleaning and Restoration of Part or Area After NDI, paragraph 1.4.16. The vibration absorber, if removed, requiresassembly and installation in accordance with the applicable technical manuals listed in Table 1-1.4-14
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