Refer to Eddy Current Method, paragraph 1.4.11. Set up on test block as follows:
Null probe on test block.
Adjust phase as required to obtain horizontal lift-off.
Move probe over all three notches in test block. Adjust gain to obtain a three block vertical signal when
probe is passed over 0.040-inch notch in test block. (See the standard instrument display shown in Figure
188.8.131.52 Inspection Procedure. Refer to Eddy Current Method, paragraph 1.4.11 and Figure 4-32.
Place probe on a good area in the inspection location and null. Adjust phase as required to obtain horizontal lift-
Inspect the part.
Any signal similar to the notches in the test block are cause for rejection.
Figure 4-32. Tail Landing Gear Fork