What was found
RIGHT UPPER FUSELAGE SKIN CRACKED JUST ON FRAME 75 AT FIRST FASTENER BELOW STRINGER 2R, CRACK IS APPROX 3/8" IN LENGTH. USED FREQ=400KHZ, V-GAIN=76.0, H-GAIN=64.0, LPF=100, 50-500KHZ PROBE. ACCOMPLISHED REPAIR TO RT UPPER FUSELAGE SKIN CRACKED JUST ON FRAME 75 AT FIRST FASTENER BELOW STRINGER 2R IAW ERS-EM-53MR-1413.