UPS Plane That Crashed Had ‘Fatigue Cracks’ in Engine Mount
(Bloomberg) — Preliminary report on crash that killed 14 people, United Parcel Service Inc. It revealed that the cargo ship showed fatigue cracks in various sections securing the turbine as a result of its left engine separating shortly after takeoff this month.
National Transportation Safety Board inspectors found “evidence of fatigue cracks in addition to areas of surge failure,” the National Transportation Safety Board said in findings released Thursday.
The McDonnell Douglas MD-11F lost its left engine during takeoff from the courier’s headquarters in Louisville, Kentucky, and did not climb more than 30 feet before crashing, the report said. The dead included the crew and people on the ground.
Dramatic images in the preliminary report show the engine and its pylon separating immediately after takeoff and shooting into the air in a ball of fire. The report is the first detailed account of the November 4 crash.
Jeff Guzzetti, former chief of accident investigation for the U.S. Federal Aviation Administration, said the circumstances surrounding the UPS crash date back to 1979 when American Airlines Group Inc. He said it was “eerily similar” to the crash in which the McDonnell Douglas DC-10 flown by McDonnell Douglas crashed shortly after takeoff after the left engine separated from the aircraft. But he said the structural failure occurred in slightly different locations.
Additionally, the NTSB determined that the American Airlines crash was caused by damages resulting from improper maintenance. But Guzzetti said the agency’s initial findings in the UPS investigation did not indicate any damage caused by obvious external factors other than aging.
Following the UPS crash, the FAA has temporarily grounded all MD-11F cargo jets, pending inspections and some corrective action by operators.
This directive has since been extended to other aircraft with similar engine pylon designs. The grounding affects about 9% of UPS’s fleet and about 4% of rival FedEx Corp.
UPS said Thursday it was grounding its fleet of MD-11s “out of an abundance of caution” ahead of the FAA’s directive. The carrier and Boeing Co., which acquired McDonnell Douglas in 1997, said they would continue to support the investigation.
Investigators are trying to determine how the engine and pylon separated so soon after takeoff. They have previously stated that they examined a number of areas as part of their probe, including maintenance carried out on the aircraft several weeks ago.
The NTSB’s report indicates that a detailed visual inspection of the left engine mount structure was conducted in October 2021. A more intensive examination of the specific part that failed in the accident did not require another 8,000 takeoffs and landings.
“The initial design and maintenance requirements called for it,” Guzzetti said. “But that part failed long before that interval,” he said.
Although the preliminary report provides clues as to how the crash occurred, it may take one to two years to reach definitive conclusions.
The aircraft involved in the accident was built for Thai Airways International in the early 1990s and was converted into a freighter about 20 years ago. The plane was boarded by three General Electric Co. The CF6 engine provided power.
The MD-11 has long been out of production and today flies only for cargo operations. The last passenger flight took place more than a decade ago.
(Updated with security expert’s comment in fifth paragraph.)
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