The National Transportation Safety Board (NTSB) recently released photos of the deadly Nov. 5 plane crash at Louisville Muhammad Ali International Airport (SDF) in Kentucky, capturing the moment a UPS cargo plane's engine fell off and burst into flames shortly after takeoff.
The images were released in the NTSB's preliminary report, which notes SDF surveillance video showed the left engine and pylon separating from the wing shortly after airplane rotation, with a fire igniting on the left engine.
The left engine then crashed onto the ground, and a fire ignited near the left pylon attachment to the wing, which continued until the plane plummeted into a nearby storage yard and two buildings, according to the report.
The MD-11 has three engines - two on the wings and one on the tail. Each wing engine is attached by a pylon connected to the wing through forward and aft mounts.
DRAMATIC VIDEO SHOWS 'CATASTROPHIC' UPS PLANE DISASTER THAT LEFT AT LEAST 3 DEAD, 11 INJURED
During the incident, the left pylon's aft mount broke when both supporting arms snapped, causing the engine to detach, according to the report.
Investigators found the failure began with hidden internal cracks that spread until the metal broke apart.
The NTSB also found tiny cracks that grew over time around boltholes in the mount, until investigators said it failed under normal stress.
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Black box data showed the plane only reached about 30 feet above ground level prior to the crash, which killed 14 people, including the three pilots, and injured 23 others.
The report noted a similar failure happened on May 25, 1979, when American Airlines Flight 191 crashed at Chicago-O'Hare International Airport.
Officials determined the 1979 crash was caused by the separation of the engine and pylon, which also led to catastrophic loss of control, according to the NTSB.
Flight 191 crashed into an open field, and the wreckage scattered into an adjacent trailer park, killing all 271 people onboard the flight and two people on the ground and injuring two others.
Two days after the Nov. 5 crash, UPS grounded its entire MD-11 fleet.
An FAA Emergency Airworthiness Directive issued a day later grounded all MD-11/MD-11F aircraft until inspections were completed.
