TM 1-1520-264-23
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.)
2.17.3.6
Inspection Procedure. Refer to Eddy Current Method, paragraph 1.4.11 and Figure 2-17.
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 is cause for rejection.
NOTE
Either probe identified in paragraph 2.17.3.1 may be used depending primarily on the ease of accessibility and user
friendliness. If the probes are changed, steps 2.17.3.5 b. (1), (2), and (3) shall be repeated each time a change is
made.
2.17.3.7
Marking and Recording of Inspection Results. Mark and record the inspection results as required by
paragraph 1.3.
2.17.4
Backup Method. None required.
2.17.5
System Securing. The main rotor feathering bearing housing, if removed, requires installation in accordance with
the applicable technical manuals listed in Table 1-1.
2.18
MAIN ROTOR STRIKER PLATE AND SHIMS (MT).
2.18.1
Description (Figure 2-1. Index No. 18). The main rotor striker plate and shims attach to the feathering bearing
housing providing a contact point for the main rotor droop stop follower.
2.18.2
Defects This inspection is used to verify crack indications found visually on the main rotor striker plate and shims.
No cracks are allowed.
2.18.3
Primary Method. Magnetic Particle.
2.18.3.1
NDI Equipment and Materials. (Refer to Appendix B.)
a.
Magnetic Particle Inspection Probe/Yoke
b.
Magnetometer
c.
Black Light
d.
Fluorescent Magnetic Particles, refer to Table 1-8
e.
Consumable Materials, refer to Table 1-8
f.
Aircraft Marking Pencil, refer to Table 1-8
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