The National Transportation Safety Board (NTSB) is conducting a formal inquiry into the November 4, 2025, crash of UPS Flight 2976 at Louisville Muhammad Ali International Airport, which resulted in 15 fatalities.

美國國家運輸安全委員會 (NTSB) 正就 2025 年 11 月 4 日在路易維爾穆罕默德·阿里國際機場發生的 UPS 2976 號航班墜機事故進行正式調查，該事故導致 15 人死亡。

The incident commenced during takeoff when the left engine and pylon detached from the wing of the 34-year-old aircraft. This separation was attributed to metal fatigue within the engine mount, specifically involving the failure of a steel bearing and metal sheath. The resulting crash caused significant casualties among the three crew members and twelve individuals on the ground, while the high fuel volume—approximately 38,000 gallons—exacerbated the subsequent conflagration.

該事件發生在起飛過程中，當時一架機齡 34 年之飛機的左側引擎與吊架從機翼脫落。此次脫落被歸因於引擎安裝座的金屬疲勞，具體涉及一個鋼製軸承與金屬護套的失效。隨後的墜機導致三名機組人員及地面的十二名人士重大傷亡，而約 38,000 加侖的高燃油量更加劇了隨後的大火。

Central to the NTSB's inquiry is the relaxation of maintenance protocols. In 2015, the Federal Aviation Administration (FAA) approved a Boeing request to extend the inspection interval for these critical components from 19,900 to 29,260 cycles. Evidence suggests that Boeing utilized antiquated data from the 1980s and failed to disclose seven known instances of bearing failure prior to this request. Had the original schedule been maintained, the subject aircraft—which had completed 21,043 cycles—would have undergone a comprehensive inspection before the failure occurred.

NTSB 調查的核心在於維修協定的放寬。2015 年，美國聯邦航空管理局 (FAA) 批准了波音的請求，將這些關鍵部件的檢查間隔從 19,900 次循環延長至 29,260 次循環。證據顯示，波音使用了 1980 年代的陳舊數據，且在提出此請求前未披露七起已知的軸承失效案例。若維持原定時程，該架已完成 21,043 次循環的飛機在失效前應已接受全面檢查。

Stakeholder positioning reveals a complex distribution of responsibility. The NTSB has questioned the FAA's lack of skepticism regarding Boeing's request and the manufacturer's lack of transparency. Boeing officials acknowledged a failure to communicate known risks, though some records from the original McDonnell Douglas era are unavailable. UPS maintained that it adhered to federally approved schedules and asserted that a 2011 Boeing notice regarding structural failures did not mandate specific action. Furthermore, it was disclosed that the flight crew had been reassigned to this aircraft after their previous vessel was sidelined due to a fuel leak.

相關利益方的立場揭示了複雜的責任分佈。NTSB 質疑 FAA 對波音的請求缺乏懷疑態度，以及製造商缺乏透明度。波音官員承認未能溝通已知風險，儘管部分麥道時期的紀錄已不可得。UPS 主張其遵守聯邦核准的時程，並聲明波音 2011 年關於結構失效的通知並未要求採取特定行動。此外，據披露，該飛行機組在之前的飛機因燃油洩漏而停飛後，才被重新指派至此架飛機。

The NTSB investigation remains active, while the FAA has approved a revised safety plan involving bearing replacements every 4,000 cycles, allowing some operators to return the MD-11 to service.

NTSB 的調查仍持續進行中，而 FAA 已批准一項修訂後的安全計劃，要求每 4,000 次循環更換軸承，允許部分營運商恢復 MD-11 的服務。