TM 1-1520-265-23
4.31.3.7. Marking and Recording of Inspection Results. Mark and record inspection results as required by paragraph
1.3.
4.31.4. Backup Method. Fluorescent Penetrant, refer to paragraph 1.4.7.
4.31.5. System Securing. The yoke, if removed, requires installation in accordance with the applicable technical
manuals listed in Table 1-1.
4.32. TAIL LANDING GEAR FORK (ET).
4.32.1. Description (Figure 4-1. Index No. 32). The fork assembly, secured to the yoke assembly is the attachment
point for the tail wheel and allows the wheel to swivel through 360° for ground control.
4.32.2. Defects. Defects may occur anywhere on the surface of the tail landing gear fork. No cracks are allowed.
4.32.3. Primary Method. Eddy Current.
4.32.3.1. 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, 0.040 EDM notches)
f.
Teflon Tape, refer to Table 1-8
g.
Aircraft Marking Pencil, refer to Table 1-8
4.32.3.2. 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 landing gear fork shall be removed in accordance with the
applicable technical manuals listed in Table 1-1.
4.32.3.3. Access. Not applicable.
4.32.3.4. Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
4.32.3.5. NDI Equipment Settings.
a.
Make the following initial settings on the Eddy Current Inspection Unit, NORTEC-19eII.
Frequency F1
- 200 KHz
F2
- off
HdB
- 57.0
VdB
- 69.0
Rot
- 560
Probe drive
- mid
4-74
