TM 1-1520-253-23
NDI_CH/MH-47F3_19
3.19.3.7 Marking and Recording of Inspection Results. Mark and record as required by paragraph
3.19.4 Backup Method. Fluorescent Penetrant, refer to paragraph 1.4.7.
3.19.5 System Securing. If removed, install the engine transmission as required in accordance
with the applicable technical manuals listed in Table 1-1. Secure the aft transmission work platform.
TRANSMISSION OIL COOLER ASSEMBLIES (PT).
3.20.1 Description (Figure 3-1, Index No. 20). This inspection is applicable to the forward, aft,
combining and engine transmission oil cooler assemblies to verify all indications found visually.
3.20.2 Defects. Defects may occur anywhere on the surface of the oil cooler. Any damaged area
shall be inspected both before and after rework. No cracks are allowed.
3.20.3 Primary Method. Fluorescent Penetrant.
3.20.3.1 NDI Equipment and Materials. (Refer to Appendix B). Inspection is listed in Table 1-7.
AMS-2644, level 3 penetrant materials shall be selected from the approved list in Table 1-8. Parts
requiring fluorescent penetrant inspection shall be cleaned prior to inspection with n-Propyl Bro-
mide (vapor degreasing only) (Table 1-8). DS-108 (Table 1-8), DS-108, Electron, Positron must be
followed by an Acetone (Table 1-8) or Isopropyl Alcohol (Table 1-8) rinse or wipe; or drying until
there is no visible solvent residue left on parts.
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