TM 1-1520-253-23
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. (Refer to standard instrument display shown in Figure
3.2.3.6
Inspection Procedure. Refer to Eddy Current Method, paragraph 1.4.11 and Figure 3-2.
a. Place probe on part in the inspection location and null. Adjust phase as required to obtain horizontal lift-off.
b. Inspect the part. (Rotation of blades may be necessary.)
c.
Any signal similar to the notches in the test block is cause for rejection.
NOTE
Either probe identified in paragraph 3.2.3.1 may be used depending primarily on the ease of
accessibility and user friendliness. If the probes are changed, steps 3.2.3.5 b. (1), (2), and (3)
shall be repeated each time a change is made.
3.2.3.7 Marking and Recording of Inspection Results. Mark and record as required by paragraph 1.3.
3.2.4 Backup Method. Fluorescent Penetrant, refer to paragraph 1.4.7.
3.2.5 System Securing. If removed, install the adapters in accordance with the applicable technical manual listed in
Table 1-1. Secure the cabin crown tunnel covers.
3.3.1 Description (Figure 3-1. Index No. 3). This inspection is applicable to the steel adapters contained within the
forward and aft driveshafting. The adapters are on the aft ends of the forward shafts 1 through 6 and aft shaft number 8.
3.3.2 Defects. Defects may occur anywhere on the surface of the adapters. Particular attention shall be given to areas
around bolts. No cracks are allowed.
3.3.3 Primary Method. Magnetic Particle.
3.3.3.1 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
