# NTSB DCA89MA063: Mcdonnell Douglas DC-10-10, N1819U, Sioux City, IA, July 19, 1989

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Class 1 · Major · Final report
- Date: July 19, 1989, 16:00 local (21:00 UTC)
- Place: Sioux City, IA
- Location: 42.4013° N, 96.3844° W: Placed by OpenAirDocs at SIOUX GATEWAY/BRIG GENERAL BUD DAY FLD (SUX), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.4013&lon=-96.3844&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 111 fatal, 47 serious, 125 minor, 13 uninjured
- Status: Completed, report October 8, 1992
- Report: Board-adopted at Board Meeting
- Investigation class: Class 1
- NTSB office: Major Investigations Division
- Safety recommendations: Yes
- NTSB case key (mKey): 15920
- NTSB case page: https://www.ntsb.gov/investigations/Pages/DCA89MA063.aspx
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15920/pdf
- Page: https://openairdocs.org/ntsb/DCA89MA063

## 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

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, cruise - normal
  - compressor assembly,forward fan - fatigue (cause)
  - maintenance,overhaul,major - inadequate, company maintenance personnel (cause)
  - inadequate quality control, manufacturer (cause)
  - compressor assembly,forward fan - failure,total (cause)
  - misc,engine uncontained failure
  - hydraulic system,line - overload
  - flight control system - inoperative
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing

## 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](https://openairdocs.org/deregistered/N1819U-1990-06-15), registration cancelled 1990-06-15, S/N 46618 (OpenAirDocs)
- Reported make and model: MCDONNELL DOUGLAS DC-10-10
- Registry model: [Mcdonnell Douglas DC-10-10](https://openairdocs.org/model/mcdonnell-douglas-dc-10-10) (registry code 3022110) (OpenAirDocs)
- Category: Airplane
- Serial number: 46618
- Engines: GE CF6-6D 51000 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

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 57; 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 (OpenAirDocs).

- [Accident 19890719023719A](https://openairdocs.org/incident/19890719023719A), Jul 19, 1989: Doug DC1010, Sioux City, IA, Destroyed, 111 fatal. Engine fan ruptured. Debris cut hydraulic flight controls. Maintenance failed detect fatigue cracks.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.