TM 1-1520-253-23
2.11.3.7 Marking and Recording of Inspection Results. Mark and record as required by paragraph 1.3.
NOTE
Attention shall be directed to accurately mark the boundaries of all voids on both sides of the
blade. These markings will be needed to determine acceptance or rejection criteria in
accordance with applicable technical manuals.
2.11.4 Backup Method. None required.
2.11.5 System Securing. Secure the forward and aft transmission work platforms.
2.12.1 Description (Figure 2-1. Index No.12).The pitch links are between the swashplates and pitch varying housings.
Tilting a swashplate up or down moves the pitch link and pitch arm in the same direction. This increases or decreases
the blade pitch angle.
2.12.2 Defects. Defects may occur anywhere on the surface of the pitch link. No cracks are allowed.
2.12.3 Primary Method. Magnetic Particle.
2.12.3.1 NDI Equipment and Materials. (Refer to Appendix B.)
a.
Magnetic Particle Inspection Probe/Yoke
b.
Magnetometer
c.
Black Light
d.
Fluorescent Magnetic Particles
e.
Consumable Materials, refer to Table 1-8
f.
Aircraft Marking Pencil, refer to Table 1-8
NOTE
Hand-held coil may be used in lieu of Position 1 only provided the link is detached from one end
or removed from helicopter. Refer to Paragraph 1.4.8.1.2 and Figure 1-6.
2.12.3.2 Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance. 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 links shall be removed in accordance with the applicable
technical manuals listed in Table 1-1.
2.12.3.3 Access. Access is from the forward and aft transmission work platforms. See Figure 1-4 -CH-47: 9, 27, and/or
34; MH-47: 16 and 17.
2.12.3.4 Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
2.12.3.5 NDI Equipment Settings. Refer to Magnetic Particle Method, paragraph 1.4.8.
