TM 1-1520-265-235.5.3.3 Access. Access to the aft engine mount strut is through hinged engine cowls (Figure 1-4, Items 3T-5 and 4T-8).WARNINGMaintenance Platforms/WorkstandsUse only appropriate platforms, workstands, or other approved locally procured stands andrestraint equipment when working above 10 feet on helicopters in a nontactical environment.Otherwise, personnel injury could result from accidental falls.5.5.3.4Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,paragraph 1.4.4.5.5.3.5NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.5.5.3.6Inspection Procedure. A magnetic field shall be applied to the part perpendicular to the orientation ofpossible cracks. Positions required for this inspection are illustrated in Figure 5-5.a.Select AC on the AC/DC power switch.b.Place probe/yoke on part in position I 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 5.5.3.8.f.Repeat steps a. through e. for positions 2 and 3.g.Repeat steps a. through f. for each strut.5.5.3.7Marking and Recording of Inspection Results. Mark and record inspection results as required byparagraph 1.3.5.5.3.8Demagnetization. With the switch remaining in the AC position, place the probe/yoke legs in the sameposition used for magnetizing. Press the test switch and withdraw the probe/yoke from the part for a distance of two feetbefore releasing the switch.5.5.4BackupMethod. Fluorescent Penetrant, refer to paragraph 1.4.7.5.5.5SystemSecuring. Clean the struts thoroughly to remove all residual magnetic particle media. Refer toPost Cleaning and Restoration of Part or Area After NDI, paragraph 1.4.f16. The engine mount struts, if removed,requires installation in accordance with the applicable technical manuals listed in Table 1-1.5.6 AFT ENGINE MOUNT FITTINGS (MT).5.6.1Description(Figure5-1.IndexNo.6).The aft engine mount struts are attached to the aft mount fittings(two inboard and one outboard) which are secured to the airframes.5.6.2Defects. Cracks may occur anywhere on the aft engine mount fittings. No cracks are allowed.5-9
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