# NTSB LAX85FA101: Bell 206B, N59549, Trimmer, CA, January 8, 1985

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Field investigation · Final report
- Date: January 8, 1985, 09:15 local (17:15 UTC)
- Place: Trimmer, CA
- Location: 36.9049° N, 119.2962° W: Placed by OpenAirDocs: center of Trimmer, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=36.9049&lon=-119.2962&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 24455
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX85FA101
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24455/pdf
- Page: https://openairdocs.org/ntsb/LAX85FA101

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, climb
  - fuel system,fuel control - undetermined (cause)
- Forced landing, descent - emergency
  - autorotation - performed, pilot in command
- On ground/water encounter with terrain/water, landing
  - terrain condition - downhill (contributing factor)
  - directional control - not possible, pilot in command

## Analysis

THE PLT STATED THE HELICOPTER LOST PWR DURING CRUISE WHEN HE ATTEMPTED TO ADD PWR TO CLIMB. HE STATED THAT N2 DECREASED ALONG WITH THE ACTIVATION OF VISUAL AND AUDIO ENGINE OUT WARNINGS. AN AUTOROTATION WAS PERFORMED TO A ROAD, HOWEVER, THE HELICOPTER SLID OFF THE ROAD AND DOWN A 50 DEG SLOPE IN THE TERRAIN BEFORE COMING TO REST. POST ACCIDENT TESTS REVEALED THE FUEL GOVERNOR, P/N 104100A12-A8, HAD AN EXCESSIVE LEAKAGE RATE AT THE BYPASS VALVUE AND THE DECELERATION AND SLOPE TESTS WERE OUT OF LIMITS. WHEN RETESTED, THE GOVERNOR WAS FOUND CAPABLE OF NORMAL OPERATION.

## Aircraft

- Registration: [N59549](https://openairdocs.org/deregistered/N59549-2012-09-27), registration cancelled 2012-09-27, S/N 1387, built 1974 (OpenAirDocs)
- Reported make and model: BELL 206B
- Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs)
- Registry engine: [Allison 250 SER 400HP](https://openairdocs.org/engine/allison-250-ser-400hp) (registry code 03013, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1387
- Airframe hours: 4813
- Engines: ALLISON 250-C20B 317 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Positioning, Part 91
- Registered owner: Rogers Helicopter, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, December 7, 1984, 11 hours before
- Departed: FRESNO, CA
- Destination: LAKE WISHON, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 4,820 total, 850 in this make and model, 4,620 as pilot in command, 76 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 48 °F, dew point 43 °F
- Altimeter: 30.00 inHg
- Observed at: FAT, 22 nm away

## 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 19850108025839A](https://openairdocs.org/incident/19850108025839A), Jan 8, 1985: Bell 206B, Trimmer, CA, Substantial damage. Engine quit, landed on road then slid down slope. Fuel governor bypass valve leaking, but able to operate normally.

## Other investigations on N59549 (1)

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.

- [NTSB OAK76FVG27](https://openairdocs.org/ntsb/OAK76FVG27), Oct 4, 1975: Bell 206B (N59549), Alder Springs, CA, substantial damage

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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