TM 1-1520-264-23
3.22.3
Primary Method. Eddy Current.
3.22.3.1
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.
Reference Block, three-notchedmagnesium (0.008, 0.020, and 0.040 EDM notches)
g.
Teflon Tape, refer to Table 1-8
h.
Aircraft Marking Pencil, refer to Table 1-8
3.22.3.2
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 tail rotor gearbox shall be removed in accordance with
the applicable technical manuals listed in Table 1-1.
3.22.3.3
Access. Access is through the tail rotor transmission fairings (Figure 1-4, Items L540 and L546).
Maintenance Platforms/Workstands
Use only appropriate platforms, workstands, or other approved locally procured stands and restraint equipment when
working above 10 feet on helicopter in a nontactical environment. Otherwise, personnel injury could result from
accidental falls.
3.22.3.4
Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
3.22.3.5
NDI Equipment Settings.
a.
Make the following initial settings on the Eddy Current Inspection Unit, NORTEC-19e11.
Frequency F1
- 200 KHz
F2
- off
HdB
- 57.0
VdB
- 69.0
Rot
- 560
Probe drive
- mid
LPF
- 100
HPF
-0
H Pos
- 80%
VPos
-20%
3-50
