TM 1-1520-265-23
3.5 TAIL ROTOR DRIVE SHAFT SUPPORTS (ET).
3.5.1 Description (Figure 3-1. Index No. 5). The tail rotor drive shaft support attaches the tail rotor drive shafts to the
airframe throughout the tail cone section of the helicopter.
3.5.2 Defects. This inspection is used to verify crack indications found visually on the tail rotor drive shaft supports. No
cracks are allowed.
3.5.3 Primary Method. Eddy Current.
3.5.3.1 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
3.5.3.2 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 drive shaft shall be removed in accordance with the applicable
technical manuals listed in Table 1-1.
3.5.3.3 Access. Access to the tail rotor drive shaft supports varies considerably. Refer to Figure 1-4 and Table 1-2 to
locate applicable access provisions.
WARNING
Maintenance Platforms/Workstands
Use only appropriate platforms, workstands, or other approved locally procured stands and
restraint equipment when working above 10 feet on helicopters in a nontactical environment.
Otherwise, personnel injury could result from accidental falls.
3.5.3.4 Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
3.5.3.5 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
3-11
