TM 1-1520-265-23
Change 3
2-27
2.13.3.6 Inspection Procedure. Refer to Eddy Current Method, paragraph 1.4.11 and Figure 2-13.
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 2.12.3.1 may be used depending primarily on the
ease of accessibility and user friendliness. If the probes are changed, steps 2.12.3.5
b. (1), (2), and (3) shall be repeated each time a change is made.
2.13.3.7 Marking and Recording of Inspection Results. Mark and record inspection results as
required by paragraph 1.3.
2.13.4 Backup Method. None required.
2.13.5 System Securing. The damper assembly, if removed, requires installation in accordance
with the applicable technical manuals listed in Table 1-1.
2.14 PITCH CONTROL RODS (ET).
2.14.1 Description (Figure 2-1, Index No. 14). The pitch control rods extend from the rotating
swashplate to the blade pitch horn on the spindle. The pitch control rods transmit all movement of
the flight controls from the swashplate to the main rotor blades.
2.14.2 Defects. Defects may occur anywhere on the pitch control rods. All areas where rework
has been performed shall be inspected for cracks. No cracks are allowed.
2.14.3 Primary Method. Eddy Current.
2.14.3.1 NDI Equipment and Materials. (Refer to Appendix B.)
a. Eddy Current Inspection Unit
b. Probe, straight, shielded surface, 2 MHz
c. Probe, right angle, shielded surface, 2 MHz, 90_ 1/2 inch drop
d. Cable Assembly
e. Adapter, probe, 2 MHz
f. Reference Block, three-notched titanium (0.008, 0.020, 0.040 EDM notches)
g. Teflon Tape, refer to Table 1-8
h. Aircraft Marking Pencil, refer to Table 1-8
2.14.3.2 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 pitch
control rods shall be removed in accordance with the applicable technical manuals listed in Table
1-1.
