# NTSB DEN84LA239: Aerospatiale 316B, N4246, Naturita, CO, July 26, 1984

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 26, 1984, 07:45 local (13:45 UTC)
- Place: Naturita, CO
- Coordinates: 38.210994, -108.559608 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.2110&lon=-108.5596&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 16446
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN84LA239
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16446/pdf
- Page: https://openairdocs.org/ntsb/DEN84LA239

## 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, cruise
  - compressor assembly,blade - corroded (cause)
  - maintenance,inspection - inadequate, company maintenance personnel (cause)
  - compressor assembly,blade - failure,total (cause)
- Forced landing, descent - emergency
- Hard landing, landing - flare/touchdown

## Analysis

ONE OF THE AXIAL COMPRESSOR BLADES SEPARATED RESULTING IN INTERNAL ENGINE DAMAGE AND LOSS OF ENGINE POWER. EXAMINATION OF THE BLADES SHOWED EVIDENCE OF CORROSION BEYOND ACCEPTABLE LIMITS. THE ENGINE WAS NOT EQUIPPED WITH AN AIR FILTER OR PARTICLE SEPARATOR. HELICOPTER DAMAGE WAS SUSTAINED DURING GROUND CONTACT.

## Aircraft

- Registration: [N4246](https://openairdocs.org/deregistered/N4246-2013-07-02), registration cancelled 2013-07-02, S/N 1884, built 1971 (OpenAirDocs)
- Reported make and model: AEROSPATIALE 316B
- Registry model: [Aerospatiale SE3160 ALOUETTE III](https://openairdocs.org/model/aerospatiale-se3160-alouette-iii) (registry code 8680605) (OpenAirDocs)
- Registry engine: [Turbomeca ARTOUSTEIIIB](https://openairdocs.org/engine/turbomeca-artousteiiib) (registry code 60003, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1884
- Airframe hours: 6253
- Engines: TURBOMECA ARTOUSTE IIB 562 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Other work use, Part 133
- Operator: Alpine Helicopter Services Inc
- Registered owner: Kjerstad Helicopters
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, July 25, 1984, 3 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 8,500 total, 150 in this make and model, 15 in the last 90 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 60 statute miles
- Lowest ceiling: none
- Temperature: 70 °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 19840726034899A](https://openairdocs.org/incident/19840726034899A), Jul 26, 1984: Aerosp SE3160, Naturita, CO, Substantial damage. Crash occurred during autorotation landing. All axial compressor blades had severe erosion. One blade separated.

## Other investigations on N4246 (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 DEN78FTE91](https://openairdocs.org/ntsb/DEN78FTE91), Aug 22, 1978: Aerospatle SA316B (N4246), Norwood, CO, 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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