Methods for detecting defects in an anisotropic rotor blade using a phased array ultrasound system

A method for detecting defects in an anisotropic rotor blade using a phased array ultrasound system, the anisotropic rotor blade extending along an axial centerline and comprising a mounting portion and an airfoil, the method comprising:

• positioning a probe of the phased array ultrasound system on the mounting portion of the anisotropic rotor blade at the axial centerline;
• scanning a sector of the anisotropic rotor blade along the axial centerline with the probe of the phased array ultrasound system, a geometric fiducial marker disposed at least partially within the sector of the anisotropic rotor blade;
• determining a magnitude and a time delay of an echo signal corresponding with the geometric fiducial marker;
• adjusting a position of one of the anisotropic rotor blade or the probe based on the magnitude of the echo signal corresponding with the geometric fiducial marker;
• and
• repeating the scanning, determining, and adjusting steps until the magnitude and the time delay of the echo signal corresponding with the geometric fiducial marker is within a predetermined maximum echo range;
• and
• scanning the anisotropic rotor blade for defects.