TM 1-1520-265-23
b.
Refer to Eddy Current Method, paragraph 1.4.11. Set up on test block as follows:
(1)
Null probe on test block.
(2)
Adjust phase as required to obtain horizontal lift-off.
(3)
Move probe over all three notches in test block. Adjust gain to obtain a three block vertical signal when
probe is passed over 0.040-inch notch in test block. (See the standard instrument display shown in Figure
1-7.)
4.18.3.6. Inspection Procedure. Refer to Eddy Current Method, paragraph 1.4.11 and Figure 4-18.
a.
Place probe on a good area in the inspection location and null. Adjust phase as required to obtain horizontal lift-
off.
b.
Inspect the part.
c.
Any signal similar to the notches in the test block are cause for rejection.
NOTE
Either probe identified in paragraph 4.18.3.1 may be used depending primarily on the ease of
accessibility and user friendliness. If the probes are changed, steps 4.18.3.5 b. (1), (2), and (3)
shall be repeated each time a change is made.
4.18.3..7 Marking and Recording of Inspection Results. Mark and record inspection results as required by paragraph
1.3.
4.18.4. Backup Method. None required.
4.18.5. System Securing. The tail pylon lower step, if removed, requires installation in accordance with the applicable
technical manuals listed in Table 1-1.
4.19. STABILATOR ATTACH FITTING (ET).
4.19.1. Description (Figure 4-1. Index No. 19). The stabilator attach fitting is integrated into the aft end of the tail pylon
on both the right and left side. The horizontal stabilator is attached to these fittings.
4.19.2. Defects. This inspection is used to detect cracks in the lug area of the left and right fittings. No cracks are
allowed.
4.19.3. Primary Method. Eddy Current.
4.19.3.1. NDI Equipment and Materials. (Refer to Appendix B.)
a.
Eddy Current Inspection Unit
b.
Probe, straight, shielded surface, 100 KHz-500 KHz
c.
Probe, right angle, shielded surface, 100 KHz-500 KHz, 90° 1/2 inch drop
d.
Cable Assembly
e.
Reference Block, three-notched aluminum (0.008, 0.020, 0.040 EDM notches)
f.
Teflon Tape, refer to Table 1-8
g.
Aircraft Marking Pencil, refer to Table 1-8
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