Critical components of the crashed freighter in the United States were found to show signs of metal fatigue.

On November 20th local time, it was reported that the National Transportation Safety Board of the United States stated that evidence of metal fatigue cracks was found in key parts of the fuselage of the crashed McDonnell Douglas MD-11 freighter. A McDonnell Douglas MD-11 cargo plane operated by United Parcel Service crashed shortly after takeoff from Louisville International Airport in Kentucky on the 4th, resulting in 14 fatalities. The NTSB pointed out that most of the structure of the left engine pylon remained attached to the engine during the accident but had separated from the wing. Investigators found signs of metal fatigue cracks on components connecting the engine to the wing.