TM 1-1520-265-235-22 Change 45.13 HIRSS AND NACELLE FAIRING SUPPORT MOUNTS (PT).5.13.1 Description(Figure5-1,IndexNo.13). The hover infrared suppression system is containedwithin the HIRSS module. Parts of the support mounts are: fail-safe plate, rear suppressor supportfitting and link, lower nacelle support fitting and link, and upper nacelle support fitting and link.5.13.2 Defects. Defects can occur anywhere on the surface of the described parts. No cracks areallowed.5.13.3 PrimaryMethod. Eddy Current.5.13.3.1 NDI Equipment and Materials. (Refer to Appendix B.)a. Eddy Current Inspection Unitb. Probe, straight, shielded surface, 100 KHz-500 KHzc. Probe, right angle, shielded surface, 100 KHz-500 KHz, 90_ 1/2 inch dropd. Cable Assemblye. Reference Block, three-notched aluminum (0.008, 0.020, 0.040 EDM notches)f. Teflon Tape, refer to Table 1-8g. Aircraft Marking Pencil, refer to Table 1-85.13.3.2 Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenancein accordance with the applicable technical manuals listed in Table 1-1.5.13.3.3 Access. Not applicable.5.13.3.4 Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part orArea for NDI, paragraph 1.4.4.5.13.3.5 NDI Equipment Settings.a. Make the following initial settings on the Eddy Current Inspection Unit, NORTEC-19eII.Frequency F1 - 200 KHz F2 - offHdB - 57.0VdB - 69.0Rot - 56_ Adjust as neededProbe drive - midLPF - 100HPF - 0H Pos - 80% Adjust as neededV Pos - 20% Adjust as neededb. Refer to Eddy Current Method, paragraph 1.4.11. Set up on test block as follows:(1) .Null probe on test block.(2) .Adjust phase as required to obtain horizontal lift-off.(3) .Move probe over all three notches in test block. Adjust gain to obtain a three block verticalsignal when probe is passed over 0.040-inch notch in test block. (See the standardinstrument display shown in Figure 1-7.)
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