What was found
FOUND A 17 INCH LONGITUDINAL CRACK, AT THE 12 O'CLOCK POSITION, IN THE TOP SKIN OF SECT 3 OF THE AFT S-DUCT NEAR ANTI-ICE PLENUM, FOUND NUMEROUS STIFFENER ANGLES CRACKED AROUND OUTER CIRCUMFERENCE OF AFT SECT OF DUCT. FALCON JET SB NR 220 ON THIS DUCT, WHICH IF INCORP, WOULD HAVE PREVENTED THIS CRACK FROM OCCURRING. THE NEW REPLACEMENT DUCT, PN F50B258720A2, HAS BEEN MANUFACTURED TO ADDRESS THE PROBLEM AND CONFORMS TO MODIFICATION 1667, WHILE SUPERSEDES MODIFICATION 1666/AND SB 220.