Plane whose engine flew off before it exploded in fireball and killed 14 was suffering from 'metal fatigue'

The US National Transportation Safety Board (NTSB) has identified "metal fatigue" in an engine mount as the probable cause of the fatal UPS cargo plane crash in Louisville, Kentucky, which killed 14 people. A preliminary report details that the 34-year-old McDonnell Douglas MD-11 sustained critical cracks in the hardware connecting its left engine to the airframe. This structural failure led to the engine detaching during takeoff from Louisville Muhammad Ali International Airport, resulting in a catastrophic fire and the aircraft's subsequent crash.

Following the incident, UPS proactively grounded its entire MD-11 fleet, demonstrating immediate concern for operational safety. The US Federal Aviation Administration (FAA) swiftly issued an Emergency Airworthiness Directive (EAD) for the MD-11, mandating inspections and potential repairs for all aircraft of this type, citing the unsafe condition's likelihood across similar designs. This directive later expanded to include nine additional models, signaling a broader industry concern regarding aging aircraft components and maintenance protocols. The grounding and required inspections pose significant operational and financial challenges for major cargo carriers like UPS and FedEx, which utilize these aircraft extensively.

The NTSB's findings raise critical questions about the efficacy of current maintenance schedules and inspection methods. While UPS had reportedly conducted inspections within required timeframes, including a visual check of the pylon just seven days before the crash, the fatigue cracks went undetected. Aviation experts, including former federal crash investigator Jeff Guzzetti, suggest the FAA will now scrutinize the adequacy of these inspection intervals. The incident draws parallels to a 1979 American Airlines DC-10 crash, highlighting a recurring vulnerability in engine pylon attachments for these aircraft types, prompting calls for advanced detection technologies beyond visual inspections.