The National Transportation Safety Board (NTSB) has revealed Boeing knew about a faulty part on the MD-11 flown by UPS that crashed in Louisville in November. In 2011, Boeing stated that the failure of the part “would not result in a safety of flight condition.”

The NTSB report says Boeing knew there was a structural flaw with the part for almost 15 years. While not officially cited as a cause of the crash in Kentucky that killed 15 people, the NTSB said that cracks in the assembly holding the left-side engine in place may have contributed to the crash.

According to the New York Times, the part had fractured in a similar fashion on at least four other occasions, on three different airplanes, and twice on the same plane. Boeing even wrote a letter to operators about it in 2011, saying it was aware of the part’s failures.

In November, the NTSB reported that parts of the bearing assembly connecting the left engine to the cargo plane’s wing had fractured and showed signs of “fatigue cracks” and “overstress failure.”

According to the new NTSB report, Boeing recommended in its 2011 letter that the maintenance team inspect the part every 60 months as part of a general visual inspection. A maintenance team last conducted a general visual inspection on the UPS plane 49 months prior to the crash.

Boeing has a long history of suspicious incidents involving their planes

In May 2024, one of Boeing’s 767 cargo planes crash landed on a runway in Istanbul after its landing gear failed. That same month, a Boeing 737-300 skidded off the runway while on fire at Blaise Diagne International Airport in Dakar, Senegal. On that same day, a Boeing 737 broke its nose landing gear while landing in Turkey, causing one of the plane’s tires to burst.

In April of 2024, multiple passenger videos revealed the terrifying moment that an engine cover was ripped off a Boeing 737-800 during takeoff from Denver International Airport. Also in April, a Boeing 767 passenger jet had its emergency slide deploy and fall to the ground shortly after taking off from JFK Airport in New York.

That March, a United Airlines Boeing 777 lost a tire after takeoff, damaging several vehicles on the ground. In January of that same year, a door plug on Alaska Airlines flight 1282 blew off the Boeing 737 while flying at about 16,000 feet.

Those incidents caused such concern that they led to the creation of a website where travelers could check whether their flight would be on a Boeing plane. Also around that same time, two Boeing whistleblowers died suddenly and under mysterious circumstances after they publicly questioned the causes of safety failures on multiple Boeing jets. One of the dead whistleblowers had raised several concerns about the 787-8 Dreamliner, the same plane that crashed in India, killing 241 people in June of 2025.