# NTSB ANC89FA092: Aerospatiale AS350B, N160EH, Puntilla Lake, AK, June 15, 1989

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 15, 1989, 09:40 local (17:40 UTC)
- Place: Puntilla Lake, AK
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report July 9, 1990
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5113
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC89FA092
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5113/pdf
- Page: https://openairdocs.org/ntsb/ANC89FA092

## Probable cause

THE PILOT CONTINUED VFR FLIGHT INTO INSTRUMENT METEOROLOGICAL CONDITIONS (IMC) AND FAILED TO MAINTAIN SUFFICIENT ALTITUDE TO CLEAR THE MOUNTAINOUS TERRAIN.  THE WEATHER AND TERRAIN CONDITIONS WERE CONTRIBUTING FACTORS.

## Sequence of events

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

- In flight encounter with weather, cruise
  - terrain condition - high terrain (contributing factor)
  - weather condition - clouds (contributing factor)
  - weather condition - low ceiling (contributing factor)
  - weather condition - fog (contributing factor)
  - weather condition - rain (contributing factor)
  - vfr flight into imc - continued, pilot in command (cause)
- In flight collision with terrain/water, cruise
  - terrain condition - mountainous/hilly (contributing factor)
  - terrain condition - rising (contributing factor)
  - proper altitude - not maintained, pilot in command (cause)

## Analysis

THE AIR TAXI PLT WAS RETURNING THE HELICOPTER TO ITS BASE CAMP AFTER TRANSPORTING PASSENGERS & PARTS TO A REMOTE DRILLING SITE IN RURAL ALASKA. WHILE EN ROUTE, THE HELICOPTER COLLIDED WITH THE ROCK FACE OF A 3900 FT RIDGE AT THE 3500 FT LEVEL. THE WX IN THE AREA WAS RPRTD TO BE OVERCAST BTN 3000 & 3500 FT MSL WITH LIGHT TO OCCASIONALLY HEAVY RAIN. THE PLT HAD AN INSTRUMENT RATING FOR AIRPLANES, BUT NOT FOR HELICOPTERS. HE WAS RPRTDLY IN THE HABIT OF FLYING OVER THE RIDGES, WHEN WX PERMITTED, TO MINIMIZE FLT TIME, INSTEAD OF FOLLOWING LOWER TERRAIN IN NEARBY VALLEYS.

## Aircraft

- Registration: [N160EH](https://openairdocs.org/deregistered/N160EH-1992-04-23), registration cancelled 1992-04-23, S/N 2071 (OpenAirDocs)
- Reported make and model: AEROSPATIALE AS350B
- Registry model: [S N I A S AS-350B ECUREUIL](https://openairdocs.org/model/s-n-i-a-s-as-350b-ecureuil) (registry code 8680801) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2071
- Airframe hours: 680
- Engines: TURBOMECA ARRIEL 1B 650 horsepower turbo shaft
- Damage: Destroyed
- Fire: On-Ground
- Flight: Part 135
- Registered owner: Era Aviaiton
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, April 13, 1989, 82 hours before
- Departed: NONE, PUNTILLA LAKE, AK
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 52; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; toxicology performed; flight hours: 12,400 total, 2,500 in this make and model

## Weather

- Conditions: Day
- Temperature: 39 °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 19890615015679A](https://openairdocs.org/incident/19890615015679A), Jun 15, 1989: Snias AS350B, Puntilla Lake, AK, Destroyed, 1 fatal. Impacted rock face of a ridge in level flight. Cloud base known to be near ridges. Light to moderate rain existed.

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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