What was found
(CAN) WHILE PERFORMING AD CF-1997-07R2, NDT INSP OF FRONT AND REAR SPAR WING TO FUSELAGE FRAME ANGLES A CRACK WAS DETECTED ON THE REAR LT OB ANGLE. THE CRACK ORIGINATED AT THE TOP HI-LOK AND WAS HEADED UP ABOUT .1250 TH OF AN INCH. IT COULD NOT BE DETECTED BY THE NAKED EYE. THE AD WAS ACTUALLY DUE AT A/F TIME 2573.4 AND WATER DROPS 9726. WE PERFORMED IT DURING WINTER MAINT AT A/F 2530.8 AND 9521 WATER DROPS. APPROVED REPAIRS WILL BE CARRIED OUT AND THE AC RELEASED FOR SERVICE. (TC NR 20080331001)