TM 1-1520-264-23
5.5.3
Primary Method. Fluorescent Penetrant.
5.5.3.1
NDI Equipment and Materials. (Refer to Appendix B.) Inspection equipment is listed in Table 1-7. MIL-I-25135
level 3 penetrant materials shall be selected from the approved list in Table 1-8.
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 this procedure. If required, the part(s) shall be removed in accordance with the applicable
technical manuals listed in Table 1-1.
5.5.3.3
Access. Refer to Figure 1-4 as applicable.
5.5.3.4
Preparation of Part. Refer to Preparation of Part or Area for NDI, paragraph 1.4.4.
5.5.3.5
Inspection Procedure. Perform fluorescent penetrant inspection. Refer to Fluorescent Penetrant Method,
paragraph 1.4.7 and Table 1-5. Inspect area of concern. See Figure 5-5.
5.5.3.6
Marking and Recording of Inspection Results. Mark and record the inspection results as required by paragraph
1.3.
5.5.4
Backup Method. None required.
5.5.5
System Securing. Clean the part(s) to remove inspection media. Refer to Post Cleaning and Restoration of
Part or Area After NDI, paragraph 1.4.16. The part(s), if removed, requires installation in accordance with the applicable
technical manuals listed in Table 1-1.
5.6
AIR INLET ASSEMBLY (ET).
5.6.1
Description (Figure 5-1. Index No. 6)
. The aluminum air inlet assembly is at the front of the engine through
which air is directed into the engine.
5.6.2
Defects. This inspection is used to verify crack indications found visually on the air inlet. No cracks are
allowed.
5.6.3
Primary Method. Eddy Current.
5.6.3.1
NDI Equipment and Materials. (Refer to Appendix B.)
a.
Eddy Current Inspection Unit
b.
Probe, straight, shielded surface, 100 KHz-500 KHz
c.
Probe, right angle, shielded surface, 100 KHz-500 KHz, 90
° 1/2 inch drop
d.
Cable Assembly
e.
Reference Block, three-notched aluminum (0.008, 0.020, and 0.040 EDM notches)
f.
Teflon Tape, refer to Table 1-8
g.
Aircraft Marking Pencil, refer to Table 1-8
5.6.3.2
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 air inlet assembly shall be removed in accordance with the
applicable technical manuals listed in Table 1-1.
5-10
