# NTSB SEA93LA209: Aerospatiale SA 315B, N351RM, Avery, ID, September 24, 1993

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: September 24, 1993, 16:00 local (22:00 UTC)
- Place: Avery, ID
- Coordinates: 47.17068, -115.800125 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.1707&lon=-115.8001&mi=10
- Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 2 minor
- Status: Completed, report September 26, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 41775
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA93LA209
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41775/pdf
- Page: https://openairdocs.org/ntsb/SEA93LA209

## Probable cause

THE PILOT'S IMPROPER USE OF THE CYCLIC CONTROL.

## Sequence of events

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

- On ground/water collision with object, standing - engine(s) operating
  - object - tree(s)
  - cyclic - improper use of, pilot in command (cause)

## Analysis

THE HELICOPTER WAS ON A NARROW PAD WITH THE ENGINE RUNNING WHEN THE MAIN ROTOR BLADES STRUCK A NEARBY TREE STUMP. THE HELICOPTER BEGAN SPINNING AND PITCHED OVER THE SIDE OF THE LANDING PAD AND COLLIDED WITH A TREE.

## Factual narrative

On September 24, 1993, at 1600 mountain daylight time, the main rotor blades on an Aerospatiale, SA 315B Lama, N351RM, struck a tree stump while standing on a narrow landing pad near Avery, Idaho.  The pilot was unable to maintain control of the helicopter as it pitched over and rolled down the steep hill.  Visual meteorological conditions prevailed at the time and no flight plan was filed.  The helicopter was substantially damaged and the certificated commercial pilot was seriously injured.  The two passengers received minor injuries.

The operator reported that the helicopter had been conducting logging operations throughout the day.  At the end of the day, the helicopter landed on the narrow pad to pick up and transport personnel from the logging site.  As the helicopter was standing with the engine running, one passenger was strapped into her seat, the other passenger was just boarding, when a loud bang was heard.  The helicopter suddenly started to spin around and the one boarding passenger was thrown out of the helicopter.  The pilot was unable to maintain control, and the helicopter travelled over the edge of the pad and rolled down the hill.

It was later found that the main rotor blade struck a tree stump that was in close proximity to the pad and approximately five feet, two inches above the skids.

## Aircraft

- Registration: [N351RM](https://openairdocs.org/deregistered/N351RM-2013-05-30), registration cancelled 2013-05-30, S/N 2502, built 1977 (OpenAirDocs)
- Reported make and model: AEROSPATIALE SA 315B
- Registry model: [Aerospatiale SA315B](https://openairdocs.org/model/aerospatiale-sa315b) (registry code 8680615) (OpenAirDocs)
- Registry engine: [Turbomeca ARTOUSTEIIIB](https://openairdocs.org/engine/turbomeca-artousteiiib) (registry code 60003, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2502
- Airframe hours: 14550
- Engines: TURBOMECA ARTOUSTE IIIB 858 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Positioning, Part 91
- Operator: Rocky Mountain Helicopters
- Registered owner: Burr, James B.
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, September 21, 1993, 61 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 3,900 total, 55 in this make and model, 3,800 as pilot in command, 115 in the last 90 days, 55 in the last 30 days, 8 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 360° at 10 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 63 °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 19930924036409A](https://openairdocs.org/incident/19930924036409A), Sep 24, 1993: Aerosp SA315B, Avery, ID, Substantial damage. While loading personnel from logging site idlin rotors struck tree stump. Helicopter began spin. Rolled down hills.

## Other investigations on N351RM (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 SEA90FA158](https://openairdocs.org/ntsb/SEA90FA158), Aug 7, 1990: Aerospatiale SA315B (N351RM), Cougar, WA, destroyed. Probable cause: LOSS OF POWER DUE TO CONTAMINATION IN THE ENGINE SPEED GOVERNOR.

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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