TM 1-1520-265-23g.The Bondmaster is programmed to automatically set test parameters to a start-up or initial bond test. Byfollowing the steps outlined above, adjustments to the FREQ, GAIN, and ALARM can help to refine theselectivity in locating defects among differing bonded metallic and composite materials.2.20.3.6 Inspection Procedure. Refer to Bond Testing Method, paragraph 1.4.6 and inspection areas shown in Figure 2-20.a.Skin-to-Honeycomb Voids. Place probe on main rotor blade in location where test for skin-to-honeycomb bondseparation is desired and press NULL. Move probe from good to suspect area and note response. A strongamplitude change and phase shift similar to the standard is indicative of a void. This set-up is very sensitive tothin skin-to-core bonding. Move probe slowly over the skin and note the slight amplitude change (bounce) as theprobe senses alternately the honeycomb cell nodes and cell walls.NOTEThe basic set-up provided above also selects a frequency that provide a satisfactory inspectionfor voids associated with skin-to-spar, skin-to-trailing edge, doubler-to-doubler and doubler-to-skin, and trim tab bonding.b.Use the NULL and GAIN adjustments to reset the ACTIVE screen for the areas to be inspected (do not go backto SET mode). Also, compare similar areas. For example, to check for spar to skin voids, check front and backof blade in the same area, or check another blade in the same area. Observe that, when moving the probechordwise 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 theprobe carefully along the transition using a straight edge or other guide. A localized phase and amplitude shiftsimilar to the test block indicates a void.2.20.3.7 Marking and Recording of Inspection Results. Mark and record as required by paragraph 1.3.NOTEAttention shall be directed to accurately mark the boundaries of all voids. These markings willbe needed to determine acceptance or rejection criteria in accordance with applicable technicalmanuals.2.20.4 BackupMethod. None required.2.20.5 SystemSecuring. None required.2.21 MAIN ROTOR BLADE CUFF ASSEMBLY (ET).2.21.1 Description(Figure2-1.IndexNo.P1). The main rotor blade cuff assembly is bolted and bonded to the inboardend of the main rotor blade. It provides a bolted attachment for the main rotor blade to the main rotor head spindle.2.21.2 Defects. This inspection is used to verify crack indications found visually on the main rotor blade cuff assembly.No cracks are allowed.2-48
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