Fatal Crash

Federal investigators found signs of metal fatigue and stress fractures in the engine mount of a UPS cargo plane that crashed in Louisville, Kentucky, earlier this month.

Context

The crash occurred on November 4 when a UPS MD-11 freighter attempted to take off from Louisville's Muhammad Ali International Airport. The plane was fully loaded with fuel for a scheduled flight to Honolulu and carried three crew members. The aircraft reached only 30 feet in altitude before crashing into buildings beyond the runway, killing all three crew members and 11 people on the ground.

Engine Detachment

On Thursday, the National Transportation Safety Board released a preliminary report showing that the plane's left engine detached during takeoff.

Video footage captured the engine separating from the wing, flying above the fuselage in flames, and hitting the ground. The aircraft's landing gear then struck a UPS warehouse roof before the plane crashed into an industrial area that included a petroleum recycling facility.

Metal Fatigue Discovered

Investigators found evidence of fatigue cracks and overstress failure in components of the pylon, the structure that connects the engine to the wing.

The report identified cracks in multiple sections that secured the engine, including fractures in two places of the bracket meant to hold the engine in place. The plane had undergone a visual inspection of the left engine mount structure in October 2021, but more intensive inspections were not yet due.

Safety Response

Following the crash, the Federal Aviation Administration (FAA) issued an emergency directive grounding all MD-11 cargo jets pending inspections.

The directive later expanded to other aircraft with similar engine-pylon designs. Both UPS and FedEx grounded their MD-11 fleets before the FAA order. The MD-11, which is over three decades old and no longer in production, is only used for cargo operations today.