Place probe on a good area in the inspection location-and null. Adjust phase as required
to obtain horizontal lift-off.
Inspect the part.
Any signal similar to the notches in the test block is cause for rejection.
Either probe identified in paragraph 184.108.40.206 may be used depending primarily on the ease of accessibility
and user friendliness. If the probes are changed, steps 220.127.116.11 b. (1), (2), and (3) shall be repeated each
time a change is made.
18.104.22.168 Marking and Recording of Inspection Results. Mark and record the inspection results as required by paragraph
Backup Method. None required.
System Securing. The main rotor mast support base, if removed, requires installation in accordance with the
applicable technical manuals listed in Table 1-1.
INTERMEDIATE GEARBOX (Et).
Description (Figure 3-1. Index No. 19). The intermediate gearbox transmits power from the main transmission
to the tail rotor gearbox. The intermediate gearbox is mounted on the vertical stabilizer.
Defects. This inspection is used to verify crack indications found visually on the intermediate
gearbox. No cracks are allowed.
Primary Method. Eddy Current.
22.214.171.124 NDI Equipment and Materials. (Refer to Appendix B.)
Eddy Current Inspection Unit
Probe, straight, shielded surface, 100 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