111 fatal · MCDONNELL DOUGLAS DC-10-10 · 1989-07-19 · SIOUX CITY, IA, USA
Event
NTSB number
DCA89MA063
Event ID
20001213X28786
Type
Accident
Date
1989-07-19
Location
SIOUX CITY, IA, USA
Injuries
Highest injury
FATL
Fatal
111
Serious
47
Minor
125
Uninjured
13
Total aboard
296
Aircraft
Make
MCDONNELL DOUGLAS
Model
DC-10-10
Registration
N1819U
FAR Part
121
Engines
3
Damage
DEST
Conditions
Light
DAYL
Weather
VMC
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.