TM 1-1520-265-23
4.14.3.6 Marking and Recording of Inspection Results. Mark and record inspection results as required by paragraph
1.3.
4.14.4
Backup Method. None required.
4.14.5
System Securing. Clean the door assembly to remove inspection media. Refer to Post Cleaning and
Restoration of Part or Area After NDI, paragraph 1.4.16. The door assembly, if removed, requires installation in
accordance with the applicable technical manuals listed in Table 1-1.
4.15
TAIL PYLON ATTACH FITTING (ET).
4.15.1
Description (Figure 4-1. Index No. 15). The tail pylon is attached to the tail cone by a hinge
assembly mounted on the cone. This inspection is applicable to the pylon and cone attaching structures, and in particular
for cracks in the surface around the lower barrel nut holes in the tail rotor gear-box fitting.
4.15.2
Defects. This inspection is used to verify crack indications found visually on the pylon/cone attaching
structures. No cracks are allowed.
4.15.3
Primary Method. Eddy Current.
4.15.3.1 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
4.15.3.2 Preparation of Helicopter. The helicopter shall be prepared for safe groundmaintenance in accordance with
the applicable technical manuals listed in Table 1-1.
4.15.3.3 Access. Open the tail pylon.
4.15.3.4 Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
4.15.3.5 NDI Equipment Settings.
a.
Make the following initial settings on the Eddy Current Inspection Unit, NORTEC-19e".
Frequency F1
-200 KHz
F2
- off
HdB
- 57.0
VdB
- 69.0
Rot
- 56°
4-36
