Southwest Airlines Flight 866
Boeing 737-3H4 · Incident: airframe, component or system failure during takeoff
From Lubbock Preston Smith International Airport (LBB) to Albuquerque International Sunport (ABQ)
Event
- NTSB case
- FTW95IA348
- 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
- Incident
- 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 737-3H4
- Aircraft type
- Boeing 737
- 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
- N309SW
- Operator
- Southwest Airlines
- Onboard fatalities
- Unknown
- Route
- From Lubbock Preston Smith International Airport (LBB)To Albuquerque International Sunport (ABQ), Albuquerque, NM
- 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 121: Air Carrier
- 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
- Takeoff · roll/run
- 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
- Minor
Cause areas
- Landing gear, wheel › Failure
- Landing gear, wheel › Incorrect
- Other maintenance personnel › Maintenance, rebuild/remanufacture, improper
Approximate · Estimated position: the centre of Lubbock, TX, the place the record names. Not the accident site.
NTSB narrative
During takeoff at Lubbock, Texas, the number three wheel assembly separated from the axle. The aircrew continued the flight and landed uneventfully at Albuquerque, New Mexico. Company maintenance records indicated the wheel assembly was last replaced on August 16, 1995. Examination of the aircraft revealed that the axle nut was intact on the axle along with the tang washer. The axle nut locking ring was also in place. The outer bearing was found deteriorated with only its inner race remaining, and the inner bearing remained intact on the axle. Examination of the components revealed that, an incorrect inner bearing had been installed inadvertently by the wheel assembly supplier on the number three wheel assembly. A Timkin part number 594 bearing was installed in lieu of the correct Timkin part number 596 bearing.
Probable cause
installation of an incorrect bearing in the number three main wheel by the wheel assembly supplier, which led to subsequent failure of the wheel bearing and separation of the wheel during takeoff.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW95IA348
- Event ID
- 20001207X04228
- Case number
- FTW95IA348
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- 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: 56a4d96aadafb81bb571caa30418fd59313fea9a7d64255da30bd5d0c40fc60f; retrieved 2026-09-18T17:58:04.410Z.
- The NTSB's operator name is blank for N309SW; the operator shown is the name the NTSB's other records give its FAA operator code, SWAA.