Figure 2-22. Tail Rotor Blade (Voids)
The basic set-up provided above also selects a frequency that provides a satisfactory inspection
for voids associated with skin-to-spar, skin-to-trailing edge, doubler-to-doubler and doubler-
to-skin, and trim tab bonding.
Use the NULL and GAIN adjustments to reset the ACTIVE screen for the areas to be inspected (do not go back
to SET mode). Also, compare similar areas. For example, to check for spar to skin voids, check front and back
of blade in the same area, or check another blade in the same area. Observe that, when moving the probe
chordwise from the spar to the trailing edge, the transitions at the spar-to-honeycomb and the honeycomb-to-
trailing edge strip are easily detected. When inspecting these areas, adjust the NULL and GAIN and move the
probe carefully along the transition using a straight edge or other guide. A localized phase and amplitude shift
similar to the test block indicates a void.
220.127.116.11 Marking and Recording of Inspection Results. Mark and record as required by paragraph 1.3.
Attention shall be directed to accurately mark the boundaries of all voids. These markings will
be needed to determine acceptance or rejection criteria in accordance with applicable technical
2.22.4 Backup Method. None required.
2.22.5 System Securing. The tail rotor blade, if removed, requires installation in accordance with the applicable technical
manual listed in Table 1-1.