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LAX93LA124 · Bertone CHALLENGER II CHALLENGER

18 Feb 1993 · Boulder City, NV, United States

Bertone CHALLENGER II CHALLENGER · Accident: loss of control in flight

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Event

NTSB case
LAX93LA124
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
Visual Meteorological Cond

Bertone CHALLENGER II CHALLENGER

Aircraft type
Bertone CHALLENGER
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
N4391V
Operator
Frank D. Graham · private individual
Onboard fatalities
Unknown
Route
From not recordedTo not recorded
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
Unknown
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
Loss of control 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
Destroyed

Cause areas

  • Pilot in command › Aircraft control, not maintained
  • Pilot in command › Impairment(drugs)
  • Pilot in command › Physical impairment(other cardiovascular)

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

NTSB narrative

THE PILOT HAD CALLED ANOTHER PILOT ON THE RADIO AND SAID THAT HE WAS 5 MI SOUTH OF THE AIRPORT AND RETURNING TO LAND. WHEN THE PILOT DID NOT RETURN, THE OTHER PILOT TOOK OFF TO SEARCH FOR THE PILOT. THE AIRPLANE WAS LOCATED 3 MI SOUTH OF THE AIRPORT. EXAMINATION OF THE AIRPLANE REVEALED THE AIRPLANE IMPACTED THE TERRAIN NOSE FIRST AT A 40-45 DEG ANGLE. THE PROPELLER APPEARED NOT TO HAVE BEEN TURNING AT IMPACT. AN EXAM OF THE ENGINE FOUND NO MECHANICAL DISCREPANCIES. TOXICOLOGICAL RESULTS WERE POSITIVE: BLOOD SCREEN - 1026 NG/ML DIAZEPAM, 1142 NG/ML NORDIAZEPAM; URINE SCREEN - METHAMPHETAMINE, AMPHETAMINE, OXAZEPAM, TEMAZEPAM, AND NORDIAZEPAM IDENTIFIED. THE LEVEL OF DIAZEPAM WOULD INDICATE THAT THE PILOT WAS TAKING THE TRANQUILIZER VALIUM AT A LEVEL OF AT LEAST TWICE THE NORMAL THERAPEUTIC CONCENTRATION. IN ADDITION, THE AUTOPSY REVEALED A SEVERE OCCLUSION OF THE LEFT ANTERIOR DESCENDING ARTERY, AT ITS ORIGIN. THE DEGREE OF OCCLUSION WAS SUFFICIENT TO HAVE CAUSED ARRHYTHMIA, INFARCT OR EVEN DEATH AT ANY TIME.

Probable cause

THE PILOT'S LOSS OF AIRPLANE CONTROL DUE TO PHYSICAL IMPAIRMENT AS A RESULT OF EITHER DRUGS OR OTHER CARDIOVASCULAR REASONS, OR BOTH.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX93LA124
Event ID
20001211X11847
Case number
LAX93LA124
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: 54bc198a4e2b2ae4c3c4efa6cb959d8891659d3a15bdbd71af498825661bd1b3; retrieved 2026-09-21T00:42:16.600Z.