British Airways Boeing 747-136 accident
Boeing 747-136 · Accident: airframe, component or system failure on approach
From London Heathrow Airport (EGLL) to Chicago O'Hare International Airport (ORD)
Event
- NTSB case
- CHI88FA110
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Boeing 747-136
- Aircraft type
- Boeing 747
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- GAWND
- Operator
- British Airways
- Onboard fatalities
- Unknown
- Route
- From London Heathrow Airport (EGLL), LondonTo Chicago O'Hare International Airport (ORD)
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 129: Foreign
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Approach · IFR final approach
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Flight control, flap attachment › Failure, total
- Flight control, flap attachment › Stress corrosion
- Manufacturer › Acft/equip, inadequate design
Approximate · Estimated position: the centre of Chicago, IL, the place the record names. Not the accident site.
NTSB narrative
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.
Probable cause
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI88FA110
- Event ID
- 20001213X25642
- Case number
- CHI88FA110
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: e1675eed0e91cfe86026991bad582bf36ca899f999b85fd9c74b13ead1c1738d; retrieved 2026-09-18T19:22:35.867Z.