TM 1-1520-264-23
2.25.3.6
Marking and Recording of Inspection Results. Mark and record the inspection results as required by
paragraph 1.3.
2.25.4
Backup Method. None required.
2.25.5
System Securing. Clean the tail rotor blade to remove inspection media. Refer to Post Cleaning and
Restoration of Part or Area After NDI, paragraph 1.4.16. The tail rotor blade, if removed, requires installation in
accordance with the applicable technical manuals listed in Table 1-1.
2.26 TAIL ROTOR BLADE (VOIDS) (BT).
2.26.1
Description (Figure 2-1. Index No. 26). The tail rotor blade assemblies are rotating airfoils. The blade is
constructed with a stainless steel leading edge. Eleven aluminum honeycomb stiffeners are bonded into the spar, and
the blade skin is aluminum with bonded doublers near the root fitting.
2.26.2
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
subdefinitions 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").
2.26.3
Primary Method. Bond Testing.
2.26.3.1
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
2.26.3.2
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 blades in accordance with
the applicable technical manuals listed in Table 1-1.
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