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United Airlines Boeing 737-322 accident

6 Jun 1996 · San Francisco, CA, United States

Boeing 737-322 and American Airlines Boeing 767-223 · Accident: collision between aircraft (not in flight) during pushback

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Event

NTSB case
LAX96LA222
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

Aircraft 1 · Boeing 737-322

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
N371UA
Onboard fatalities
Unknown
Route
From San Francisco International Airport (SFO)To Seattle–Tacoma International Airport (SEA), Seattle, WA
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
Pushback/towing
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
Collision between aircraft (not in flight)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Aircraft 2 · Boeing 767-223

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
N335AA
Onboard fatalities
Unknown
Route
From San Francisco International Airport (SFO)To John F. Kennedy International Airport (JFK), New York City, NY
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
Taxi · to runway
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
Collision between aircraft (not in flight)
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

  • Driver of vehicle › Visual lookout, inadequate

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

At night, a tail-to-tail ground collision occurred in an alleyway between an outbound United Boeing 737, N371UA, and an outbound American Boeing 767, N335AA. At the time, the B-737 was under tug control while being pushed back without the aid of wing walkers from gate number 77. The United B-767 was beginning to taxi from the same alleyway following its earlier uneventful pushback with the aid of wing walkers from gate number 63. According to the B-737's tug driver, during pushback she had observed a nearby food service truck and had initially slowed her speed to ensure its passage. Thereafter, she continued pushing the B-737 toward the designed alleyway location. Suddenly, an impact occurred and the tug driver for the first time observed an American B-767 was already located in the alleyway. United management reported that during pushback operations it was the tug driver's responsibility to ensure that adequate clearance existed. Nine months earlier United management was aware that aircraft utilizing its gate number 77 did not have the minimum 25-foot aircraft wing tip clearance as required by the City of San Francisco. City personnel agreed to allow United gate usage provided United 'guarantee the use of wing walkers.'

Probable cause

inadequate visual lookout by the United Airlines tug driver during the pushback operation. Contributing factors were: the driver's reduced ability to observe the American B-767 due to the nighttime condition, and United Airlines management's failure to ensure that safety procedures were followed.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX96LA222
Event ID
20001208X06027
Case number
LAX96LA222
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 1996-06-07.
  • API snapshot SHA-256: d62d1082fafed159fa117127b6234741f319ca55d59ee3e018402313358fd132; retrieved 2026-09-18T17:49:57.746Z.