Federal safety investigators have opened two days of hearings into last year's fatal UPS cargo plane crash that killed 15 people in an inquiry that seeks to understand why an engine detached from the aircraft, causing it to plunge from the sky.
The engine separated from the MD-11's wing as it accelerated down the runway at Louisville’s Muhammad Ali International Airport last November. The crash killed three pilots on board and 12 people on the ground and more were injured.
Jennifer Homendy, chair of the National Transportation Safety Board, addressed victims' families in her opening remarks: "Please know: Your loved ones are the reason we’re here. We want to find out what happened."
The hearings, involving NTSB staff, Boeing, UPS, labour unions, and other parties, will conclude on Wednesday. A final NTSB report is not expected for over a year as investigators examine every potential factor.
The crash
The UPS plane, which was headed for Hawaii loaded with packages and fuel, had barely left the ground and cleared the airport fence when it crashed into several nearby Louisville businesses and created a massive fireball.
Dramatic photos the NTSB released after the crash showed the engine detaching and flying up and over the wing as flames erupted on the wing. The final images show the plane ablaze as it briefly gets airborne, leaving behind trails of smoke.
All MD-11s and DC-10s, a predecessor aircraft, were grounded after the crash. NTSB investigators said Tuesday that similar part flaws were found in three other UPS planes and a DC-10.
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. That meant the crash wasn’t caused by a fatal design flaw even though there had already been a number of accidents involving DC-10s.
But even at that point, the plane's manufacturer, McDonnell Douglas, raised concerns about the spherical bearing that helps hold the engines to the wings. McDonnell Douglas later merged with Boeing.
Past problems with these planes
The NTSB said shortly after the Louisville crash that investigators had found cracks in some of the parts that held the engine to the wing.
Those cracks hadn’t been caught in regular maintenance done on the plane, which raised 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.
Boeing had documented in 2011 there were four previous failures on three different planes of a part that helps secure the MD-11’s engines to the wings, but at that point the plane manufacturer “determined it would not result in a safety of flight condition.”
The service bulletin that Boeing issued didn’t require plane owners to make repairs like an FAA airworthiness directive would, and the agency didn’t issue such a directive. At that point, Boeing just recommended replacing the bearings with a redesigned part that was less likely to fail.
MD-11 planes flying again
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 that 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.
