Place probe on a good area in the inspection location and null. Adjust phase as required to obtain horizontal lift-
Inspect the part.
Any signal similar to the notches in the test block is cause for rejection.
Either probe identified in paragraph 188.8.131.52 may be used depending primarily on the ease of accessibility and user
friendliness. If the probes are changed, steps 184.108.40.206 b. (1), (2), and (3) shall be repeated each time a change is
Marking and Recording of Inspection Results. Mark and record the inspection results as required by paragraph
Backup Method. None required.
System Securing. The catwalk, if removed, requires installation in accordance with the applicable technical
manuals listed in Table 1-1.
4.7 EMPENNAGE FRAME ASSEMBLIES F.S. 530 AND F.S. 547 AND ATTACHED STRINGERS (ET).
Description (Figure 4-1. Index No. 7). The frame assemblies are located within the tailboom and form the four
attaching points for the vertical stabilizer. Each of the attaching points protrudes through the tailboom skin at two points
at F.S. 530 and two points at F.S. 547. The stringers are attached to the inner surface of the tailboom skin along the
length of the stringers and are sandwiched between the skin and the frame flanges.
Defects. Defects can occur anywhere on the surface of the empennage frame assemblies and attached
stringers. No cracks are allowed.
Primary Method. Eddy Current.
220.127.116.11 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)
Teflon Tape, 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.