United Air Lines Flight 267
Airbus Industrie A320-232 · Incident: airframe, component or system failure during landing
From Seattle–Tacoma International Airport (SEA) to Chicago, IL
Event
- NTSB case
- CHI08IA026
- 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
- Unknown
- 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
Airbus Industrie A320-232
- Aircraft type
- Airbus A320
- 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
- N431UA
- Operator
- United Air Lines
- Onboard fatalities
- Unknown
- Route
- From Seattle–Tacoma International Airport (SEA), Seattle, WATo Chicago, IL
- 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
- Landing
- 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, anti-skid brake system › Misrouted
- Landing gear, normal brake system › Locked
- Other maintenance personnel › Brakes, anti-skid, reversed
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The airplane's left main landing gear inboard and outboard anti skid tachometers wiring were reversed during scheduled maintenance at a vendor. During landing, the inboard left main landing gear's wheels went to a high braking level and the outboard wheel did not apply braking. The airplane sustained minor damage when it exited the runway and impacted runway lighting. Post incident examination of the airplane and brake components revealed no further anomalies. The vendor that performed the scheduled maintenance indicated that their personnel did not understand that the built in test equipment test they performed did not check for cross-wired tachometers. A different specified test called out in the airplane maintenance manual and in an operator's reference document indicated this specified check would verify a cross-wired condition. The operator reported that the reference documentation associated with the scheduled maintenance involving both of the left main landing gear's tachometers was unclear and that the procedure for that maintenance was revised.
Probable cause
The misrouted and reversed antiskid wiring by vendor maintenance personnel leading to the runway excursion. Contributing to the incident were the runway sign, the vendor's maintenance personnel not understanding the entire maintenance procedures in the dual tachometer replacement, and the operator's maintenance procedures being unclear to the maintenance personnel.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI08IA026
- Event ID
- 20071023X01635
- Case number
- CHI08IA026
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2007-10-10.
- API snapshot SHA-256: a7f00ab33fafb00bf74d215068b004fdf9e5dd2d1173d78d2530d3e6e7487532; retrieved 2026-09-18T14:41:11.605Z.