AD FAA-2013-0976

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-8 and 747-8F series airplanes. This AD requires repetitive ultrasonic or dye penetrant inspections for cracking of the barrel nuts and bolts, as applicable, on each forward engine mount, and related investigative and corrective actions if necessary. This AD was prompted by a report of cracked barrel nuts found on a forward engine mount. We are issuing this AD to detect and correct cracked barrel nuts on a forward engine mount, which could result in reduced load capacity of the forward engine mount, and could result in separation of an engine under power from the airplane, and consequent loss of control of the airplane.