FLIGHT FINDINGSAVIATION OCCURRENCE MAP
Back to map

LAX91LA008 · Bell 47G4

11 Oct 1990 · Merced, CA, United States

Bell 47G4 · Accident: loss of engine power en route

Report a problem

Event

NTSB case
LAX91LA008
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

Bell 47G4

Aircraft type
Bell 47
Category
Helicopter
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
N477JM
Operator
John W. Myers · 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
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
Loss of engine power
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

  • Reason for occurrence undetermined

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

NTSB narrative

AFTER WASHING THE HELICOPTER THE PILOT TOOK-OFF ON A BUSINESS FLIGHT OVER HIS RANCH. A GROUND WITNESS HEARD THE ENGINE STOP AND OBSERVED THE HELICOPTER ENTER AN AUTOROTATIVE DESCENT. THE HELICOPTER LANDED HARD AND BURST INTO FLAMES. THE WITNESS ESTIMATED THE HELICOPTERS ALTITUDE WAS ABOUT 50 FEET ABOVE THE GROUND WHEN HE FIRST OBSERVED IT. POST ACCIDENT EXAM OF THE HELICOPTER AND ENGINE REVEALED NO EVIDENCE OF A PREIMPACT MECHANICAL MALFUNCTION OR FAILURE.

Probable cause

LOSS OF ENGINE POWER FOR AN UNDETERMINED REASON.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX91LA008
Event ID
20001212X24487
Case number
LAX91LA008
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: 32929b95d247980441837361ce9d3e87a1932bbc6facad909e2a908ea815fceb; retrieved 2026-09-21T15:34:32.939Z.