If, during setup, the flying spot deflects upward or to the side when the probe passes
over the bad part instead of the desired down deflection toward the alarm box, press
SPCL and toggle to a different phase setting (90, 180, or 270), and repeat steps d. and
e. Continue to try phase setting until the flying spot moves in the desired down direction.
Place probe on good area of test block and press RUN. Flying spot should be near the top-center of the ACTIVE
screen. If not, press NULL. Slide probe from good to void area and note response from flying spot. This
response should provide both amplitude (vertical) and phase (horizontal) movement. The default gate/alarm
setting may be incorrect for this setup. Turn off or reset gate/alarm as desired.
The Bondmaster is programmed to automatically set test parameters to a start-up or initial bond test. By
following the steps outlined above, adjustments to the FREQ, GAIN, and ALARM can help to refine the
selectivity in locating defects among differing composite materials.
220.127.116.11 Inspection Procedure. Refer to Bond Test Method, paragraph 1.4.6 and inspection areas shown in Figure 2-4.
Skin-to-Honeycomb Voids. Place probe on main rotor blade in location where test for skin-to-honeycomb bond
separation is desired and press NULL. Move probe from good to suspect area and note response. A strong
amplitude change and phase shift similar to the standard is indicative of a void. This setup is very sensitive to
thin skin-to-core bonding. Move probe slowly over the skin and note the slight amplitude change (bounce) as the
probe senses alternately the honeycomb cell nodes and cell walls.
The basic setup provided above also selects a frequency that provide 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.
18.104.22.168 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 manuals.