TM 1-1520-265-23
2.22 TAIL ROTOR BLADE (VOIDS) (BT).
2.22.1 Description (Figure 2-1. Index No. 92). The tail rotor blade is built around two graphite composite spars running
from tip-to-tip and crossing each other at the center to form the four blades. The blade spars are covered with cross ply
fiberglass to form the airfoil shape.
2.22.2 Defects. Void damage may occur anywhere on both sides of the blade.
NOTE
A void is defined as an unbonded area that is supposed to be bonded. Many sub-definitions of
voids are given, such as lack of adhesive, gas pocket, misfit, etc. However, this manual makes no
distinction among these, instead grouping them all under one general term ("void").
2.22.3 Primary Method. Bond Testing.
2.22.3.1 NDI Equipment and Materials. (Refer to Appendix B.)
a.
Bond Test Unit
b.
Probe, Mechanical Impedance Analysis
c.
Probe Holder
d.
Cable Assembly
e.
Test Block, metal honeycomb with skin thickness closest to that of the panel to be inspected.
f.
Test Block, Composite Defect Standard #1
g.
Test Block, Composite Defect Standard #3
h.
Teflon Tape, refer to Table 1-8
i.
Aircraft Marking Pencil, refer to Table 1-8
2.22.3.2 Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance. Partial inspection for
cause (visual indications, sites' of mechanical damage, corrosion, etc.) may be performed on all exposed surfaces of the
installed part using applicable positions of this procedure. If required, remove the tail rotor blade in accordance with
applicable technical manuals listed in Table 1-1.
2.22.3.3 Access. Not applicable.
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.
2.22.3.4 Preparation of Part. The components shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,
paragraph 1.4.4.
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