220.127.116.11 NDI Equipment and Materials. (Refer to Appendix B.)
Magnetic Particle Inspection Probe/Yoke
Fluorescent Magnetic Particles, refer to Table 1-8
Consumable Materials, refer to Table 1-8
Aircraft Marking Pencil, refer to Table 1-8
18.104.22.168 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 main rotor droop stop ring shall be removed in
accordance with the applicable technical manuals listed in Table 1-1.
22.214.171.124 Access. Not applicable.
126.96.36.199 Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
188.8.131.52 NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
184.108.40.206 Inspection Procedure. A magnetic field shall be applied to the part perpendicular to the orientation of possible
cracks. The position required for this inspection is illustrated in Figure 2-3.
Select AC on the AC/DC power switch.
Place probe/yoke on part in position 1 as shown.
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.
Inspect for cracks using the black light.
220.127.116.11 Marking and Recording of Inspection Results. Mark and record the inspection results as required by paragraph
18.104.22.168 Demagnetization. With the switch remaining in the AC position, place the probe/yoke legs in the same position
used for magnetizing. Press the test switch and withdraw the probe/yoke from the part for a distance of two feet before
releasing the switch.
Backup Method. None required.
System Securing. Clean the main rotor droop stop ring thoroughly to remove all residual magnetic particle
media. Refer to Post Cleaning and Restoration of Part or Area After NDI, paragraph 1.4.16. The main rotor droop stop
ring, if removed, requires installation in accordance with the applicable technical manuals listed in Table 1-1.