UPS MD-11 lost engine during November takeoff at Louisville airport, killing 15

Documents released Wednesday by crash investigators show that UPS did not require detailed inspections of engine-mount bearings on its MD-11 freighters because Boeing had told the carrier that failure of the bearings would not affect flight safety. The plane crashed last fall while accelerating down the runway at Louisville’s Muhammad Ali International Airport, killing all three pilots and 12 people on the ground and injuring 23 others.

The documents indicate Boeing had recommended the inspections years earlier.

Inspection schedule changes Boeing later petitioned the Federal Aviation Administration to extend the inspection interval from every 19,900 cycles to every 29,260 cycles. The change was granted even after seven bearing flaws had already been reported before the original limits were reached.

The crashed aircraft had completed 21,043 cycles, a figure that would have triggered inspection under the original schedule. Three additional bearing flaws were found after the interval was lengthened.

Statements from involved parties In its submission to the National Transportation Safety Board, UPS said it relied on Boeing’s representation that existing inspections were sufficient and therefore made no changes to its maintenance program. Officials from Boeing and the Federal Aviation Administration told investigators they had not understood that bearing failure could break the lugs securing engines to the wings.

Maintenance practices and fleet decisions FedEx and other MD-11 operators reported at least 10 additional bearing or attachment-part failures before the crash. FedEx resumed MD-11 flights in May after the Federal Aviation Administration approved Boeing’s updated safety plan.