# NTSB LAX92LA014: Aerospatiale AS-350D, N35961, Hilo, HI, October 14, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 14, 1991, 10:25 local (20:25 UTC)
- Place: Hilo, HI
- Coordinates: 19.689092, -155.079833 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=19.6891&lon=-155.0798&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 7 uninjured
- Status: Completed, report July 13, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27477
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92LA014
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27477/pdf
- Page: https://openairdocs.org/ntsb/LAX92LA014

## Probable cause

1) A LOSS OF ENGINE POWER DUE TO THE INGESTION OF GASSES FROM THE ACTIVE VOLCANO VENT, AND 2) THE PILOTS INFLIGHT DECISION TO HOVER DOWNWIND IN CLOSE PROXIMITY TO THE VENT.

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, hover
  - weather condition - unfavorable wind (cause)
  - compressor assembly - stall (cause)
  - in-flight planning/decision - poor, pilot in command (contributing factor)
- Hard landing, descent - emergency

## Analysis

THE HELICOPTER WAS HOVERING NEAR THE EDGE OF THE VOLCANICALLY ACTIVE CRATER AT 15 TO 20 FEET ABOVE GROUND LEVEL.  THE HELICOPTER WAS HOVERING DOWNWIND OF THE VENT.  SEVERAL LOUD POPPING SOUNDS WERE HEARD COMING FROM THE ENGINE AND THE PILOT SENSED A LOSS OF POWER.  THE PILOT AUTO ROTATED TO A DOWN SLOPE HARD LANDING AND THE MAIN ROTOR CONTACTED THE TAIL BOOM. AFTER RECOVERY FROM THE ACCIDENT SITE, THE ENGINE WAS EXAMINED WHILE STILL IN PLACE IN THE HELICOPTER. FUEL SAMPLES WERE REMOVED FROM THE TANK AND SUMP, AND FOUND TO BE CLEAR.  ALL PC AIR LINES WERE PRESSURE CHECKED, WITH A SMALL LEAK DETECTED ON THE INLET SIDE OF THE PC FILTER.  THE ENGINE WAS STARTED AND TEST RUN IN THE AIRFRAME UP TO 72% N1, WITH NO ADVERSE FINDINGS.  THE ENGINE WAS REMOVED FROM THE HELICOPTER AND SHIPPED TO THE LYCOMING FACTORY WHERE IT WAS INSTALLED IN A TEST CELL.  THE ENGINE WAS RUN FOR 50 MINUTES, TO INCLUDE AN ACCELERATION TEST.  THE ENGINE DEVELOPED AND SUSTAINED FULL POWER IN ACCORDANCE WITH THE AEROSPATIALLE AS-350D AIRFRAME APPLICATION.  NO MALFUNCTIONS OR DEFECTS WERE NOTED.

## Aircraft

- Registration: N35961 (not matched to a registry record)
- Reported make and model: AEROSPATIALE AS-350D
- Category: Helicopter
- Serial number: 1113
- Airframe hours: 5292
- Engines: LYCOMING LTS-101-600 620 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Part 135
- Operator: Papillon Hawallian Hel.
- Registered owner: Elling, Halvorson
- Airworthiness certificate: Standard, Normal
- Last inspection: Continuous airworthiness, September 27, 1991, 57 hours before
- Departed: HI07, WAIKOLOA, HI
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 2,362 total, 94 in this make and model, 2,266 as pilot in command, 143 in the last 90 days, 94 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 185° at 15 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 73 °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 19911014045839A](https://openairdocs.org/incident/19911014045839A), Oct 14, 1991: Snias AS350D, Hilo, HI, Substantial damage. Hovering low level downwind near edge of active volcano. Had compressor stall. Hard landing chopped off tailboom.

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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