# NTSB LAX91LA008: Bell 47G4, N477JM, Merced, CA, October 11, 1990

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: October 11, 1990, 10:58 local (17:58 UTC)
- Place: Merced, CA
- Coordinates: 37.350505, -120.419937 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.3505&lon=-120.4199&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report November 9, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 27041
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA008
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27041/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA008

## Probable cause

LOSS OF ENGINE POWER FOR AN UNDETERMINED REASON.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power, cruise
  - reason for occurrence undetermined (cause)
- Forced landing, takeoff - roll/run
- Hard landing, landing - flare/touchdown

## Analysis

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.

## Aircraft

- Registration: [N477JM](https://openairdocs.org/deregistered/N477JM-1993-10-22), registration cancelled 1993-10-22, S/N 3139 (OpenAirDocs)
- Reported make and model: BELL 47G4
- Registry model: [Bell 47G-4](https://openairdocs.org/model/bell-47g-4) (registry code 1181030) (OpenAirDocs)
- Category: Helicopter
- Serial number: 3139
- Engines: LYCOMING VO-540-B1B3 240 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Business, Part 91
- Operator: John W. Myers

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 79; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; flight hours: 15,000 total

## Weather

- Conditions: Visual (VMC), Dawn
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °F

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19901011045159A](https://openairdocs.org/incident/19901011045159A), Oct 11, 1990: Bell 47G4, Merced, CA, Destroyed. Engine failed at low altitude causing ground impact and fire. No defects found.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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