TM 1-1520-253-23
COMPOSITE PYLON HINGED FAIRINGS (WORK PLATFORM) (BT).
4.13.1 Description (Figure 4-1. Index No. 13). The work platforms are located on each side of the pylon which provides
access to rotor shaft.
4.13.2
Defects. Void damage may occur on any area of the skin/honeycomb structure.
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, grouping them all under one
general term ("void").
4.13.3 Primary Method. Bond Testing.
4.13.3.1
NDI Equipment and Materials. (Refer to Appendix B.)
a.
Bond Test Unit
b.
Probe, Mechanical Impedance Analysis
c.
Probe Holder
d.
Cable Assembly (compatible with Bond Testing Unit)
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.
Teflon Tape, refer to Table 1-8
h.
Aircraft Marking Pencil, refer to Table 1-8
4.13.3.2
Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance. If required, the
work platforms shall be removed in accordance with applicable technical manuals listed in Table 1-1.
4.13.3.3
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.
4.13.3.4
Preparation of Part. The components shall be thoroughly cleaned. Refer to Preparation of Part or Area for
NDI, paragraph 1.4.4.
