UPS switched planes hours before an engine fell off its aircraft, leading to a fiery crash that killed 15 people in Louisville, according to investigators. The left engine detached from the MD-11's wing as the aircraft accelerated along the runway at Louisville's Muhammad Ali International Airport in November. The plane barely cleared the airport fence before crashing into nearby businesses in a massive fireball.
All three pilots on board and 12 people on the ground were killed, with a further 23 people sustaining injuries. The National Transportation Safety Board (NTSB) is convening hearings in Washington this week focusing on what led to the tragedy.
Pre-Crash Aircraft Switch
It emerged at Tuesday's hearing that UPS had an issue with a different plane hours before the crash. A preflight inspection found a fuel leak in the first plane loaded for the trip to Hawaii. The cargo was then loaded onto a second plane, and the flight crew shared good-natured banter with the maintenance team during its inspection about "meeting again" so soon. This second plane promptly lost its left engine.
Investigators have uncovered records detailing ten prior flaws in the critical components designed to secure engines to aircraft wings. The majority of these issues were never reported to the Federal Aviation Administration (FAA). Officials from the FAA and UPS indicated that reports they did receive regarding problems with the spherical bearings, a key focus of the investigation, may have lacked sufficient detail.
Bearing Issues Downplayed
David Springer of UPS stated that Boeing's service letters made the bearing issue "sound almost benign" and failed to mention any potential collateral damage to the lugs connecting the engine to the wing. "I think if we would have known that at UPS, I think we would have asked a lot of different questions over the years," Springer said.
The NTSB released over 2,000 pages of documents as it began two days of proceedings to examine the root causes of the crash. Dramatic images released after the crash showed the engine detaching as flames erupted on the wing. The plane was already ablaze as it briefly got airborne, leaving behind trails of smoke.
Maintenance Gaps
Examining the wreckage, investigators found cracks in some of the parts that held the engine to the wing. Those cracks hadn't been caught in regular maintenance, raising questions about the adequacy of the maintenance schedule. The last time those key engine mount parts were examined closely was in October 2021, and the plane wasn't due for another detailed inspection for roughly 7,000 more takeoffs and landings.
All MD-11s and DC-10s were grounded after the Louisville crash. NTSB investigators said Tuesday that similar part flaws were subsequently found in three other UPS planes and a DC-10.
Past Problems Unreported
NTSB member Tom Chapman said investigators found ten different earlier examples of flaws in MD-11s, dating back more than 15 years, involving the same key part that failed in Louisville, but only four were reported to the FAA. Chapman said all of them should have been reported. FAA officials testified Tuesday that four, spread over years, would not have been enough to demonstrate a problem trend.
Boeing determined that those flaws "would not result in a safety of flight condition," so the plane maker didn't require plane owners to make repairs. The FAA never issued an airworthiness directive that would have ensured that was done. Instead, Boeing just recommended replacing the bearings with a redesigned part that was less likely to fail.
Historical Parallels
The Louisville disaster was reminiscent of a 1979 crash in Chicago involving a DC-10. The left engine also fell off in that crash, which killed 273 people and led to the worldwide grounding of 274 DC-10s. The airliner returned to the skies because the NTSB determined that maintenance workers had damaged the plane that crashed while improperly using a forklift to reattach the engine. However, even at that point, McDonnell Douglas raised concerns about the spherical bearing that helps hold the engines to the wings. McDonnell Douglas later merged with Boeing.
MD-11s Back in Service
Some MD-11s, a workhorse of the cargo fleet, are now back in the air after the FAA approved Boeing's plan to replace the spherical bearing on each aircraft and increase inspections. FedEx resumed using the planes to deliver packages on May 10, but UPS has said it plans to retire its fleet of MD-11s. Western Global also uses MD-11s but hasn't said what it plans to do.
Some experts speculated after the crash that the MD-11s might never fly again if the repair proved to be more expensive than it was worth in these older planes. But Boeing said it found a way to address the safety concerns simply by replacing the bearing and stepping up inspections.
