NTSB CAROL · Event
Event DCA89MA063
Aircraft involved
Probable cause & findings
THE INADEQUATE CONSIDERATION GIVEN TO HUMAN FACTORS LIMITATIONS IN THE INSPECTION AND QUALITY CONTROL PROCEDURES USED BY UNITED AIRLINES' ENGINE OVERHAUL FACILITY WHICH RESULTED IN THE FAILURE TO DETECT A FATIGUE CRACK ORIGINATING FROM A PREVIOUSLY UNDECTECTED METALLURGICAL DEFECT LOCATED IN A CRITICAL AREA OF THE STAGE 1 FAN DISK THAT WAS MANUFACTURED BY GENERAL ELECTRIC AIRCRAFT ENGINES. THE SUBSEQUENT CATASTROPHIC DISINTEGRATION OF THE DISK RESULTED IN THE LIBERATION OF DEBRIS IN A PATTERN OF DISTRIBUTION AND WITH ENERGY LEVELS THAT EXCEEDED THE LEVEL OF PROTECTION PROVIDED BY DESIGN FEATURES OF THE HYDRAULIC SYSTEMS THAT OPERATED THE DC-10'S FLIGHT CONTROLS.
Factual narrative
The Safety Board's full report on this investigation is provided as Aviation Accident Report number AAR-90/06. To obtain a copy of this report, or to view the executive summary online, please see the Web site at http://www.ntsb.gov/publictn/publictn.htm UNITED AIRLINE FLT 232 WAS CRUISING AT FL 370, WHEN THERE WAS A CATASTROPHIC FAILURE OF THE # 2 (TAIL MOUNTED) ENG. THIS WAS DUE TO SEPN, FRAGMENTATION & FORCEFUL DISCHARGE OF THE STAGE 1 FAN ROTOR ASSEMBLY PARTS FM THE #2 ENG (UNCONTAINED FAILURE), WHICH LED TO LOSS OF THE 3 HYD SYSTEMS THAT POWERED THE FLT CTLS. THE FLIGHTCREW EXPERIENCED SEVERE DIFFICULTIES CTLG THE ACFT, WHICH SUBSEQUENTLY CRASHED DRG AN EMERG LNDG AT SIOUX CITY. AN INV REVEALED EVIDENCE CONCERNING LIMITATIONS IN INSPN & QUALITY CTL PROC USED DRG ENG OVERHAUL, WHICH RESULTED IN A FAILURE TO DETECT A FATIGUE CRACK, ORIGINATING FM A PREVIOUSLY UNDETECTED METALLURGICAL DEFECT IN A CRITICAL AREA OF THE STATE 1 FAN DISK. (SEE: NTSB/AAR-90/06) Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1989_DCA89MA063.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
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Related research
What the literature says.
Academic papers and agency reports matching this event's aircraft type or causal vocabulary (human factors). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
- Embry-Riddle Scholarly Commons 2024 · Conference paper
A Comparative Study of eVTOL Inceptor Variations and Lessons Learned Through Human Factors Research
Electric vertical take-off and lift (eVTOLs) aircraft are dominating the future of Urban Air Mobility (UAM). These aircraft introduce the need for pilots to learn how to operate an aircraft that can b…
- Embry-Riddle Scholarly Commons 2024 · Conference paper
Up in the Air: A Human Factors Approach to Enhancing eVTOL Passenger Experience
Although electric vertical take-off and landing (eVTOL) vehicles are an emerging mode of transportation, current research indicates that the general public may be unwilling to ride in them due to unfa…
- Embry-Riddle Scholarly Commons 2024 · Journal article (JAAER)
Human-AI Teams in Aviation: Considerations from Human Factors and Team Science
Artificial Intelligence (AI) has transformed the way human-computer interaction (HCI) teams can collaborate and coordinate in various domains, including aviation and crew resource management (CRM).
- Embry-Riddle Scholarly Commons 2023 · Faculty research project
Human Factors Awareness Training for FAA Aviation Safety Specialists Within Aircraft Certification and FAA Flight Standards
In this project, which is funded by the FAA, Embry-Riddle and Kent University will develop training for individuals within the FAA’s Aviation Safety Flight Standards Service who have expertise and job…
- Semantic Scholar 2023 · Article (The International Journal of Aerospace Psychology)
Qualitative Analysis of General Aviation Pilots’ Aviation Safety Reporting System Incident Narratives Using the Human Factors Analysis and Classification System
ABSTRACT NASA's Aviation Safety Reporting System (ASRS) gathers data from voluntary aviation safety reports for nonfatal accidents and incidents.
- Semantic Scholar 2023 · Article (Safety)
SHIELD Human Factors Taxonomy and Database for Learning from Aviation and Maritime Safety Occurrences
Human factors (HF) in aviation and maritime safety occurrences are not always systematically analysed and reported in a way that makes the extraction of trends and comparisons possible in support of e…
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