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LAX91FA074 · Cessna 172RG

15 Jan 1991 · Hayward, CA, United States

Cessna 172RG · Accident: in flight encounter with weather en route

From Buchanan Field (CCR) to San Carlos Airport (SQL)

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Event

NTSB case
LAX91FA074
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
1 · 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
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Instrument Meteorological Cond

Cessna 172RG

Aircraft type
Cessna 172
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
N9721B
Onboard fatalities
Unknown
Route
From Buchanan Field (CCR), Concord, CATo San Carlos Airport (SQL), San Carlos, 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 91: General Aviation
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
In flight encounter with weather
Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
Visual flight rules (VFR) flight into instrument meteorological conditions (IMC)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Destroyed

Cause areas

  • Pilot in command › Altitude, not maintained

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

NTSB narrative

THE 1700 HOUR INSTRUMENT RATED PILOT WAS FAMILIAR WITH THE ROUTE OF FLIGHT BETWEEN HAYWARD (HWD) AND SAN CARLOS (SQL) HAVING REPORTEDLY FLOWN THE ROUTE TO WORK OVER 100 TIMES. THE PILOT'S SQL DESTINATION DID NOT HAVE A PUBLISHED INSTRUMENT APPROACH. SO, THE PILOT PLANNED TO EXECUTE AN IFR APPROACH TO HWD AND THEN INITIALLY FLY UNDER SVFR TOWARD SQL. APPROACHING SQL THE PILOT PLANNED TO REQUEST A SVFR CLEARANCE INTO ITS CONTROL ZONE. WHILE FLYING ENROUTE THE PILOT WOULD BE OVER OPEN WATER IN UNCONTROLLED AIRSPACE WHERE ONLY ONE MILE OF FLIGHT VISIBILITY WOULD BE REQUIRED. AFTER EXECUTING THE INSTRUMENT APPROACH TO HWD THE PILOT RECEIVED, AS PLANNED, THE REQUESTED CLEARANCE OUT OF ITS CONTROL ZONE. AFTER RECEIVING A SVFR CLEARANCE INTO SQL'S CONTROL ZONE THE PILOT FAILED TO MAINTAIN ALTITUDE AND HE DESCENDED INTO THE SAN FRANCISCO BAY. AT THE TIME THE PILOT WAS IN HWD'S AIRSPACE, ITS WEATHER WAS, IN PART: 200 FOOT OVERCAST CEILING AND ONE MILE VISIBILITY IN FOG.

Probable cause

THE PILOT'S FAILURE TO MAINTAIN ALTITUDE. CONTRIBUTING FACTORS RELATED TO THE PILOT'S IMPROPER VFR PROCEDURES AND HIS MISJUDGED EVALUATION OF THE WEATHER IN DAYLIGHT CONDITIONS. ADDITIONAL FACTORS RELATED TO THE PRESENCE OF LOW CLOUDS AND TO THE RESTRICTED VISIBILITY.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX91FA074
Event ID
20001212X16324
Case number
LAX91FA074
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: fba21508176c02d2bb364608539899fd680d005b34abf43451d96977dc8444fa; retrieved 2026-09-21T02:01:26.115Z.