Individually Owned: 150,657
Corporate Owned: 137,281
Chicago O'hare Airport
Aircraft Accident/Incident Report
Chicago, Illinois 60666
Monday, May 9, 1988 16:35 CDT
NTSB Narrative Summary Released at Completion of Accident
THE ACFT WAS ON FINAL APPROACH TO CHICAGO O'HARE INTER'L AIRPORT WHEN A STRUCTURAL FAILURE OF THE NUMBER THREE FLAP TRACK OCCURRED. THE ACFT SUSTAINED SUBSTANTIAL DAMAGE TO THE LEFT WING, LEFT INBOARD FLAP ASSEMBLY, LEFT INBOARD SPOILERS AND SPOILER SUPPORT BEAM. THE PILOT EXPERIENCED SIGNIFICANT UNCOMMANDED ROLL AND YAW, BUT REGAINED CONTROL OF THE ACFT AND EXECUTED AN UNEVENTFUL LANDING. THE INVESTIGATION HAS REVEALED A HISTORY OF FLAP TRACK CRACKING PROBLEMS ASSOCIATED WITH STRESS CORROSION AND DESIGN INADEQUACY. A DESIGN CHANGE OF THE MEMBER WAS ACCOMPLISHED IN 1971 BY THE MANUFACTURER, BUT FLAP TRACKS OF THE EARLIER DESIGN WERE ALLOWED TO REMAIN IN SERVICE ON 239 AIRCRAFT. THE AIRWORTHINESS DIRECTIVES AND SERVICE BULLETINS APPLICABLE TO THIS PARTICULAR STRUCTURAL MEMBER ARE NOT ADEQUATE IN METHODOLOGY AND PERIODICITY TO ENSURE CRACK DETECTION, AND DO NOT REQUIRE INSPECTION FOR THE CAUSE OF THE CRACK-CORROSION PITS.
NTSB Probable Cause Narrative
FAILURE OF THE NUMBER THREE FLAP TRACK DUE TO STRESS CORROSION CRACKING. FACTORS CONTRIBUTING TO THIS FAILURE ARE INSUFFICIENT DESIGN OF THE MEMBER AND INADEQUATE INSPECTION AND MAINTENANCE PROCEDURES TO DETECT CRACKS BEFORE THEY PROPAGATE TO A CRITICAL LENGTH.
Event Information
| Type of Event | Accident |
| Event Date | 5/9/1988 |
| Event Day of the Week | Monday |
| Time of Event | 1635 |
| Event Time Zone | Central Daylight Time |
| Event City | CHICAGO |
| Event State | ILLINOIS |
| Event Country | -- |
| Zipcode of the event site | 60666 |
| Event Date Year | 1988 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | CHICAGO O'HARE |
| Event Location Nearest Airport ID | ORD |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 5 |
| Degrees magnetic from airport | 90 |
| Airport Elevation | 667 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1650 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | 270 |
| Weather Observation Facility ID | ORD |
| Elevation of weather observation facility | 667 |
| Distance of event from weather observation facility (units?) | 5 |
| Time Zone of the weather observation | CDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 1000 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 3 |
| Air Temperature at event time (in degrees celsius) | 13 |
| Dew Point at event time (in degress fahrenheit) | 13 |
| Wind Direction (degrees magnetic) | 220 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 16 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | 26 |
| Altimeter Setting at event time (in. Hg) | 29 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Moderate |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 304 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 6019 |
| NTSB Notification Source | -- |
| NTSB Notification Date | May 9 1988 12:00AM |
| NTSB Notification Time | 1930 |
| Fiche Number and/or location -used to find docket information | 40016 |
| Date of most recent change to record | Dec 13 2000 11:44AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | GAWND |
| NTSB Number | CHI88FA110 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 129: Foreign |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BOEING |
| Aircraft Model | 747-136 |
| Aircraft Series Identifier | 747-136 |
| Aircraft Serial Number | 19764 |
| Certified Max Gross Weight | 733880 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | Foreign Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 395 |
| Number of Engines | 4 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Mar 9 1988 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 1868 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | BRITISH AIRWAYS |
| Aircraft Owner Street Address | SPEEDBIRD HOUSE, HEATHROW ARPT |
| Aircraft Owner City | HOUNSLOW,MIDDLE |
| Aircraft Owner State | OF |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | |
| Operator is an individual? | -- |
| Operator Name | BRITISH AIRWAYS |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | HEATHROW AIRPORT |
| Operator City | LONDON |
| Operator State | OF |
| Operator Country | |
| Operator Zip code | |
| Operator Code | BRAF |
| 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 | International |
| Operator carrying Pax/Cargo/Mail | Passenger/Cargo |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | EGLL |
| Departure City | LONDON |
| Departure State | OF |
| Departure Country | |
| Departure Time | 1330 |
| Departure Time Zone | GMT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | ORD |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Approach |
| 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 | 27L |
| Runway Length | 10140 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |