TM 1-1520-265-234.19.3.2. Preparation of Helicopter. The helicopter shall be prepared for safe ground maintenance. A partial inspectionfor cause (visual indications, sites of mechanical damage, corrosion, etc.) may be performed on all exposed surfaces ofthe installed part using this procedure. If required, the horizontal stabilator shall be removed in accordance with theapplicable technical manuals listed in Table 1-1.4.19.3.3. Access. Access is obtained by removing provisions (Figure 1-4, Items 5B-45 and 6B-46).4.19.3.4. Preparation of Part. The part shall be thoroughly cleaned. Refer to Preparation of Part or Area for NDI,paragraph 1.4.4.4.19.3.5. NDI Equipment Settings.a.Make the following initial settings on the Eddy Current Inspection Unit,NORTEC-19el1.Frequency F1- 200 KHzF2- offHdB- 57.0VdB- 69.0Rot- 56°Probe drive- midLPF- 100HPF- 0H Pos-80%V Pos-20%b.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 vertical signal whenprobe is passed over 0.040-inch notch in test block. (See the standard instrument display shown in Figure1-7.)4.19.3.6. Inspection Procedure. Refer to Eddy Current Method, paragraph 1.4.11 and Figure 4-19.a.Place probe on a good area in the inspection location and null. Adjust phase as required to obtain horizontal lift-off.b.Inspect the part.c.Any signal similar to the notches in the test block are cause for rejection.NOTEEither probe identified in paragraph 4.19.3.1 may be used depending primarily on the ease ofaccessibility and user friendliness. If the probes are changed, steps 4.19.3.5 b. (1), (2), and (3)shall be repeated each time a change is made.4-46
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
