TM 1-1520-253-23
ENGINE TRANSMISSION ADAPTER (MT).
3.9.1 Description (Figure 3-1, Index No. 9). The engine transmission adapter is externally splined
and connects the engine to the engine driveshaft.
3.9.2 Defects. Defects may occur anywhere on the surface of the adapter. Particular attention
shall be given to areas around bolt holes. No cracks are allowed.
3.9.3 Primary Method. Fluorescent Penetrant.
3.9.3.1 NDI Equipment and Materials. (Refer to Appendix B.)
a. Fluorescent Penetrant
b. Black Light
c. Consumable Materials, refer to Table 1-8
3.9.3.2 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 this procedure. If required, the
engine transmission adapter shall be removed in accordance with the applicable technical manuals
listed in Table 1-1.
3.9.3.3 Access. Access is through the engine driveshaft hinged panels. See Figure 1-4 - CH-47:
5 and 6; MH-47: 26 and 27.
3.9.3.4 Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or
Area for NDI, paragraph 1.4.4.
3.9.3.5 Marking and Recording of Inspection Results. Mark and record the inspection results as
necessary per paragraph 1.3.
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