An aircraft that crashed in Kentucky in November, resulting in 15 fatalities, had a structural flaw known to Boeing for 15 years, according to a report by the U.S. National Transportation Safety Board (NTSB). The UPS MD-11F freighter crashed after one of its engines detached from the wing during takeoff preparations at Louisville. The aircraft briefly became airborne before crashing into an industrial area, killing the three crew members and 12 people on the ground.

The NTSB's update report revealed that cracks were discovered in the engine mounting assembly, a problem previously observed in other aircraft of the same model. Boeing, the manufacturer responsible for the aircraft, had determined at the time of the initial discovery that the issue "would not result in a safety of flight condition," according to the NTSB report.

The MD-11 is an older aircraft design originally manufactured by McDonnell Douglas. Boeing acquired McDonnell Douglas in 1997 and continued to provide parts and service support for the MD-11 even after the last one was produced in 2001. The crash has raised questions about the long-term maintenance and safety oversight of aging aircraft, particularly freighters that often operate under intense schedules and in diverse environments globally.

The incident has prompted scrutiny from aviation safety experts worldwide. Concerns have been raised about the potential for similar structural issues in other MD-11 aircraft still in operation, primarily as cargo carriers. The MD-11, while no longer in production, remains a workhorse for several international cargo airlines, connecting trade routes across continents.

The NTSB investigation is ongoing, and the final report will likely include recommendations for Boeing, the Federal Aviation Administration (FAA), and operators of MD-11 aircraft. These recommendations could include enhanced inspection procedures, modifications to the engine mounting assembly, or other measures to prevent similar accidents in the future. The findings are expected to have implications for the broader aviation industry, particularly regarding the maintenance and monitoring of aging aircraft fleets.