FLIGHT FINDINGSAVIATION OCCURRENCE MAP
Back to map

LAX92LA360 · SOCATA TB-10

22 Aug 1992 · BIG BEAR, CA, United States

General aviation SOCATA TB-10 · Accident: in flight collision with object en route

From L35 to Fullerton Municipal Airport (FUL)

Show on map Search Wikipedia NTSB source dataset
Report a problem

Event

NTSB case
LAX92LA360
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
General aviation
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

SOCATA TB-10

Aircraft type
Socata TB-10
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
N20BN
Onboard fatalities
Unknown
Route
From L35To Fullerton Municipal Airport (FUL), Fullerton, 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

  • Pilot in command › Altitude, inadequate
  • Pilot in command › In-flight planning/decision, improper

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

NTSB narrative

IN HIS WRITTEN STATEMENT THE PILOT SAID THAT AFTER DEPARTURE ON RUNWAY 25 HE TURNED IN A SOUTHWEST DIRECTION TO CROSS A RIDGE LINE AT AN ALTITUDE OF ABOUT 7,900 FEET MSL. HE SAID THAT NEAR THE RIDGE LINE THEY ENCOUNTERED A SUDDEN DOWN DRAFT AND HE COULD NOT ARREST THE DESCENT PRIOR TO COLLIDING WITH TREES. AN EYE WITNESS TO THE CRASH SAID THE AIRCRAFT NEVER ACHIEVED MORE THAN ABOUT 300 FEET AGL AT ANY TIME AFTER TAKEOFF. THE WITNESS OBSERVED THE AIRCRAFT IN A NOSE HIGH ATTITUDE BEGIN A RIGHT TURN, THEN IT DESCENDED BELOW THE TOPS OF SOME TREES AND OUT OF VIEW. TWO OTHER WITNESSES REPORTED HEARING THE SOUNDS OF A LOUD AND STRONG ENGINE UNTIL THE SOUNDS OF TREE IMPACTS WERE HEARD. THE AIRPORT IS IN A MOUNTAIN VALLEY AT AN ELEVATION OF 6,750 FEET. MOUNTAIN RIDGES AND PEAKS RISE AN AVERAGE OF 2,000 FEET ABOVE THE VALLEY FLOOR ON ALL SIDES OF THE AIRPORT. THE AIRPORT IS AT THE EAST END OF THE VALLEY AND A LARGE LAKE. A DAM IS AT THE WEST END OF THE VALLEY AT A 'V' NOTCH IN THE SURROUNDING MOUNTAINS. WEST OF THE DAM THE TERRAIN DROPS OFF RAPIDLY TO THE GREATER LOS ANGELES BASIN. THE DENSITY ALTITUDE WAS CALCULATED TO BE ABOUT 9,400 FEET. OTHER PILOTS WHO DEPARTED FROM THE AIRPORT REPORTED THAT TURBULENCE EXISTED OVER THE VALLEY NEAR THE SURROUNDING RIDGES.

Probable cause

THE PILOTS DECISION TO ATTEMPT CROSSING A RIDGE LINE AT AN ALTITUDE INSUFFICIENT TO ALLOW FOR CONTINGENCY ACTIONS IN THE EVENT OF AN ENCOUNTER WITH DOWN DRAFTS OR TURBULENCE. FACTORS IN THE ACCIDENT WERE THE HIGH DENSITY ALTITUDE AND THE FLIGHT'S ENCOUNTER WITH A DOWN DRAFT.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX92LA360
Event ID
20001211X15456
Case number
LAX92LA360
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 1992-08-23.
  • API snapshot SHA-256: bd0ec72bf5e4fe81f2a61fd901c8602e6df94aea1cb7badd8419c8188f1dfeea; retrieved 2026-09-21T23:09:15.254Z.