TM 1-1520-264-23
6.2.3.6 Inspection Procedure. Refer to Eddy Current Method, paragraph 1.4.11 and Figure 6-2.
a.
Place probe on a good area in the inspection location and null. Adjust phase as required to obtainhorizontal lift-
off.
b.
Inspect the part.
c.
Any signal similar to the notches in the test block is cause for rejection.
NOTE
Either probe identified in paragraph 6.2.3.1 may be used depending primarily on the ease of accessibility
and user friendliness. If the probes are changed, steps 6.2.3.5 b. (1), (2), and (3) shall be repeated each
time a charge is made.
6.2.3.7 Marking and Recording of Inspection Results. Mark and record the inspection results as required by paragraph
1.3.
6.2.4 Backup Method. None required.
6.2.5 System Securing. The bellcrank(s), if removed, require(s) installation in accordance with the applicable technical
manuals listed in Table 1-1.
6.3 MAIN ROTOR SWASHPLATE SHOULDER PIN MATING BORES (ET).
6.3.1 Description (Figure 6-1. Index No. 3).
The task is typical for both the load bearing scissors shoulder pin and the
secondary scissors shoulder pin bores. The bores are located in the swashplate itself and mate with the removed
shoulder pins.
6.3.2 Defects. This inspection is used to verify crack indications found visually on the main rotor swashplate shoulder
pin mating bore and the secondary scissors shoulder pin bore. No cracks are allowed.
6.3.3 Primary Method. Eddy Current.
6.3.3.1 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, and 0.040 EDM notches)
f.
Teflon Tape, refer to Table 1-8
g.
Aircraft Marking Pencil, refer to Table 1-8
6.3.3.2 Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance and the main rotor
swashplate shoulder pin removed in accordance with the applicable technical manuals listed in Table 1-1.
6.3.3.3 Access. Not applicable.
6.3.3.4 Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
6-6
