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United Airlines Boeing 767-222 incident

8 Jan 1993 · Denver, CO, United States

Boeing 767-222 · Incident en route

From Newark Liberty International Airport (EWR) to San Francisco International Airport (SFO)

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Event

NTSB case
DEN93IA025
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 767-222

Aircraft type
Boeing 767
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
N601UA
Onboard fatalities
Unknown
Route
From Newark Liberty International Airport (EWR), Newark, NJTo San Francisco International Airport (SFO), San Francisco, CA
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
En route · cruise
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
Miscellaneous/other
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
None

Cause areas

  • Copilot/second pilot › Incapacitation(other organic problem)

Approximate · Estimated position: the centre of Denver, CO, the place the record names. Not the accident site.

NTSB narrative

WHILE IN CRUISE FLIGHT EN ROUTE FROM NEWARK, NEW JERSEY, TO SAN FRANCISCO, CALIFORNIA, THE FIRST OFFICER SUFFERED A GRAND MAL SEIZURE AND WAS INCAPABLE OF CONTINUING HIS DUTIES. A COMPANY PILOT RIDING AS A PASSENGER CAME TO THE FLIGHT DECK AND ASSUMED THE FIRST OFFICER'S DUTIES, AND THE AIRCRAFT MADE AN UNEVENTFUL PRECAUTIONARY LANDING IN DENVER, COLORADO, WHERE THE INCAPACITATED FIRST OFFICER WAS REMOVED TO MEDICAL FACILITIES.

Probable cause

MEDICAL INCAPACITATION OF THE FIRST OFFICER.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record DEN93IA025
Event ID
20001211X11685
Case number
DEN93IA025
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, damage. Values present in the bulk record are kept.
  • The date is the local date; the NTSB stores the UTC date 1993-01-09.
  • API snapshot SHA-256: 4ef95829ad13a03547c4064a23a5544f929a596586a2d8607611eff8db55583e; retrieved 2026-09-18T18:41:47.135Z.