TM 1-1520-265-23
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 5.4.3.1 may be used depending primarily on the ease of
accessibility and user friendliness. If the probes are changed, steps 5.4.3.5 b. (1), (2), and (3)
shall be repeated each time a change is made.
5.4.3.7
Marking and Recording of Inspection Results. Mark and record inspection results as required by
paragraph 1.3.
5.4.4
Backup Method. None required.
5.4.5
System Securing. Not applicable.
5.5 AFT ENGINE MOUNT STRUTS (IT).
5.5.1
Description (Figure 5-1. Index No. 5). The aft engine mount struts attach to fittings on the air frame and
links attach to the engine.
5.5.2
Defects. Cracks may occur anywhere on the surface of the aft engine mount struts. No cracks are
allowed.
5.5.3
Primary Method. Magnetic Particle.
5.5.3.1
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
NOTE
Hand-held magnetic coil may be used. Refer to paragraph 1.4.8.1.2 and Figure 1-6.
5.5.3.2 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 applicable positions of this procedure. If required, the struts shall be removed in accordance with the
applicable technical manuals listed in Table 1-1.
5-8
