Backup Method. None required.
System Securing. Clean the main rotor head hub load plate 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 head hub
load plate requires installation in accordance with the applicable technical manuals listed in Table 1-1.
MAIN ROTOR HUB BRACKETS (MT).
Description (Figure 2-1. Index No. 22). The main rotor hub brackets are attached at the inboard section of the
hub which provides support for the feathering bearing studs.
Defects. This inspection is used to verify crack indications found visually on the main rotor hub brackets. No
cracks are allowed.
Primary Method. Magnetic Particle.
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
Hand-held magnetic coil may be used. Refer to paragraph 188.8.131.52.2 and Figure 1-6.
Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance and the main rotor
hub bracket shall be removed in accordance with the applicable technical manuals listed in Table 1-1.
Access. Not applicable.
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
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 2-22.
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
Inspect for cracks using the black light.