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LAX92FA082 · Cessna 421C

4 Jan 1992 · Mammoth Lakes, CA, United States

Cessna 421C · Accident: in flight collision with object en route

From an unrecorded airport to Brackett Field (POC)

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Event

NTSB case
LAX92FA082
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
4 · 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 421C

Aircraft type
Cessna 421
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
N2654M
Onboard fatalities
Unknown
Route
From not recordedTo Brackett Field (POC), La Verne, 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 · climb to 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 collision with object
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
Tree(s)
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

  • Became lost/disoriented
  • Pilot in command › Preflight planning/preparation, improper

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

NTSB narrative

DUE TO THE IMPENDING ARRIVAL OF A SNOW STORM, THE CERTIFICATED COMMERCIAL PILOT AND 5 PASSENGERS DEPARTED ONE DAY EARLIER THAN PLANNED, FROM AN UNCONTROLLED AIRPORT LOCATED IN MOUNTAINOUS TERRAIN TO BEGIN A NIGHT, CROSS COUNTRY FLIGHT. INSTRUMENT METEOROLOGICAL CONDITIONS PREVAILED. PRIOR TO DEPARTURE, THE PILOT WAS GIVEN AN IFR CLEARANCE VOID TIME FROM AN ARTCC. THE PILOT WAS CLIMBING TOWARD A VOR LOCATED ABOUT 27 MILES SOUTHEAST OF THE DEPARTURE AIRPORT WHILE ATTEMPTING TO CONTACT THE ARTCC TO OPEN HIS INSTRUMENT FLIGHT PLAN. THE PILOT FAILED TO MAINTAIN TERRAIN CLEARANCE, AND BECAME LOST/DISORIENTED. THE AIRPLANE STRUCK TREES AND SNOW COVERED TERRAIN AT 10,200 FEET MSL, 7 NAUTICAL MILES AND ABOUT 22 DEGREES TO THE RIGHT OF THE INTENDED COURSE.

Probable cause

THE FAILURE OF THE PILOT TO PLAN AND CONDUCT HIS DEPARTURE FLIGHT TO AVOID HIGH MOUNTAINOUS TERRAIN, DURING WHICH THE PILOT BECAME LOST/DISORIENTED. CONTRIBUTING TO THE ACCIDENT WAS SELF INDUCED PRESSURE TO DEPART BEFORE THE ARRIVAL OF A SNOW STORM.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX92FA082
Event ID
20001211X13996
Case number
LAX92FA082
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 1992-01-05.
  • API snapshot SHA-256: e85c50156299ace3dfc3be27b72444eeb255fe0e339473b577ced5c3f741117b; retrieved 2026-09-21T01:25:04.945Z.