What was found
(CAN) PILOT FELT A VIBRATION AND UPON LANDING CHECKED MAIN ROTOR BLADES. A CRACK APPROXIMATELY 18 INCHES FROM THE ROOT, RUNNING PERPENDICULAR TO THE TRAILING EDGE WAS DISCOVERED. IT APPEARS AS IF THE BLADE DEBONDED AT A RIB, AS THE CRACK FOLLOWS STRAIGHT FROM THE RIB TOWARD THE C-CHANNEL BEFORE IT TRAILS OFF TO THE SIDE. MDHI )OEM) HAS SUGGESTED THAT THE CAUSE WAS TOO MUCH TENSION ON THE BLADES AT TIE-DOWN, OIL-CANNING BETWEEN THE RIBS PUTTING PRESSURE ON THE BOND. (TC NR 20070309003)