- Date
- July 19, 1989, 16:00 local (21:00 UTC)
- Place
- Sioux City, IA
- Injuries
- 111 fatal, 47 serious, 125 minor, 13 uninjured
- Damage
- Destroyed
- Phase of flight
- Enroute
- Aircraft
- N1819UMcdonnell Douglas DC-10-10
- Weather
- Visual (VMC) · Day
- Status
- Completed · report October 8, 1992
- Report
- Board-adopted at Board Meeting
- Investigation class
- Class 1
- NTSB office
- Major Investigations Division
- Safety recommendations
- Yes
- FAA report
- 19890719023719A
- Case key
- 15920
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
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.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
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)
Aircraft
- Registration
- N1819U
- Reported as
- Mcdonnell Douglas DC-10-10
- Category
- Airplane
- Serial number
- 46618
- Engine
- GE CF6-6D, 51,000 lbs thrust, turbo fan
- Damage
- Destroyed
- Fire
- On-Ground
- Flight
- Part 121
- Operator
- United Airlines
- Airworthiness certificate
- Standard, Transport
- Departed
- DEN · Denver, CO
- Destination
- ORD · Chicago, IL
- Flight plan
- IFR
- Airport
- SUX · Sioux Gateway, runway 22, 6,600 × 150 ft, concrete
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 57
- Certificate
- Airline transport
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--w/ waivers/lim
- Seat
- Left
- Flight hours
- 29,967 total · 7,190 in this make and model · 213 in the last 90 days · 74 in the last 30 days · 2 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 10° at 11 knots
- Visibility
- 15 statute miles
- Lowest ceiling
- 4,000 ft broken
- Temperature
- 81 °F, dew point 57 °F
- Altimeter
- 30.00 inHg
- Observed at
- SUX
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.