18.104.22.168 Marking and Recording of Inspection Results. Mark and record the inspection results as required by paragraph
22.214.171.124 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 engine nose gearbox input quill shaft 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 engine nose
gearbox input quill shaft requires installation in accordance with the applicable technical manuals listed in Table 1-1.
MAIN TRANSMISSION (ET).
Description (Figure 3-1. Index No. 13). The main transmission is the primary drive for the main rotor, tail
rotor, and accessories. The main transmission is located beneath the main rotor support mast base assembly.
Defects. This inspection is used to verify crack indications found visually on the main transmission. No cracks
Primary Method. Eddy Current.
126.96.36.199 NDI Equipment and Materials. (Refer to Appendix B.)
Eddy Current Inspection Unit
Probe, straight, shielded surface, 1 00 KHz-500 KHz
Probe, right angle, shielded surface, 100 KHz-500 KHz, 90 1/2 inch drop
Reference Block, three-notched aluminum (0.008, 0.020, and 0.040 EDM notches)
Reference Block, three-notched magnesium (0.008, 0.020, and 0.040 EDM notches)
Teflon Tape, refer to Table 1-8
Aircraft Marking Pencil, refer to Table 1-8
188.8.131.52 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 this procedure. If required, the main transmission shall be removed in accordance with the
applicable technical manuals listed in Table 1-1.
184.108.40.206 Access. Access is through the main rotor transmission panel (see Figure 1-4, Items L200
220.127.116.11 Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,