Individually Owned: 150,657
Corporate Owned: 137,281
Chicago Ohare Airport
Aircraft Accident/Incident Report
Chicago, Illinois 60666
Monday, April 28, 1997 13:00 CDT
NTSB Narrative Summary Released at Completion of Accident
The airplane experienced an uncontained failure of the 10th stage compressor disk in the right engine. The flight crew aborted the takeoff, and an emergency evacuation was conducted after an engine fire was reported to the flight crew. Metallurgical inspection of the disk revealed that it had received insufficient nickel plating when it was reworked at the operator's facility 38 flight hours and 33 cycles prior to the incident. This resulted in cadmium embrittlement of the steel. The investigation revealed the operator had no written procedures to outline the process parameters and rectifier set-ups to be used during the NiCad plating process. NiCad plating line personnel also did not have any means of checking the thickness of the nickel plating during the plating process.
NTSB Probable Cause Narrative
inadequate nickel plating was applied to the compressor disk during the rework process at the operator's overhaul facility, which resulted in a brittle fracture in the disk and an uncontained engine failure. A factor was the operator's lack of written procedures and guidance for personnel on the NiCad plating line, along with their failure to supply a method of measuring the thickness of nickel applied.
Event Information
| Type of Event | Incident |
| Event Date | 4/28/1997 |
| Event Day of the Week | Monday |
| Time of Event | 1300 |
| Event Time Zone | Central Daylight Time |
| Event City | CHICAGO |
| Event State | ILLINOIS |
| Event Country | -- |
| Zipcode of the event site | 60666 |
| Event Date Year | 1997 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | CHICAGO OHARE |
| Event Location Nearest Airport ID | ORD |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | 667 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1250 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | ORD |
| Elevation of weather observation facility | 667 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | CDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 4000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 16 |
| Dew Point at event time (in degress fahrenheit) | 7 |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 0 |
| Wind Velocity Indicator | Calm |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | Minor |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | 2 |
| Injury Total None | 56 |
| Injury Total Serious | -- |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5027 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Apr 28 1997 12:00AM |
| NTSB Notification Time | 1330 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 12:12PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N9063U |
| NTSB Number | CHI97IA117 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | Minor |
| Aircraft Fire | Ground |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Boeing |
| Aircraft Model | 737-200 |
| Aircraft Series Identifier | 737-200 |
| Aircraft Serial Number | 19944 |
| Certified Max Gross Weight | 109000 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 116 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | UNITED AIRLINES |
| Aircraft Owner Street Address | O'HARE AIRPORT PO BOX 66100 |
| Aircraft Owner City | CHICAGO |
| Aircraft Owner State | IL |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 60666 |
| Operator is an individual? | -- |
| Operator Name | |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | |
| Operator City | |
| Operator State | |
| Operator Country | |
| Operator Zip code | |
| Operator Code | |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | Scheduled |
| Indicates Domestic or International Flight | Domestic |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | ORD |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 1300 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | PHL |
| Destination City | PHILADELPHIA |
| Destination State | PA |
| Destination Country | |
| Specific Phase of Flight | Takeoff |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:30AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 32L |
| Runway Length | 13000 |
| Runway Width | 200 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |