AD FAA-2013-0975

We are superseding Airworthiness Directive (AD) 2009-18-18 for certain ATR--GIE Avions de Transport R[eacute]gional Model ATR42 and ATR72 airplanes. AD 2009-18-18 required repetitive inspections for damage and absence of repair of the cockpit forward side windows, and replacement if necessary. This new AD requires repetitive detailed inspections of the cockpit forward side window for damage and discrepancies; and replacement if necessary. Replacing both cockpit forward side windows with approved windows terminates the repetitive detailed inspections. This new AD also expands the applicability of AD 2009-18-18. The actions required by AD 2009-18-18 are not required by this AD. This AD was prompted by reports of a cockpit forward right- hand side blow out during flight. We are issuing this AD to detect and correct air/water leakage of the cockpit forward side window, which could lead to rapid cabin decompression, resulting in loss of control of the airplane.