LAX92LA014

NTSB accident investigation · Aerospatiale AS-350D · Hilo, HI · October 14, 1991

Accident · No injuriesLimited investigationFinal report
Date
October 14, 1991, 10:25 local (20:25 UTC)
Place
Hilo, HI
Injuries
7 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N35961Aerospatiale AS-350D
Weather
Visual (VMC) · Day
Status
Completed · report July 13, 1993
Report
Approved by Office Director
FAA report
19911014045839A
Case key
27477

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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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

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(total) - nonmechanicalHover
Weather condition - unfavorable windCause
Compressor assembly - stallCause
In-flight planning/decision - poorPilot in commandFactor
Hard landingDescent - 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
Reported as
Aerospatiale AS-350D
Category
Helicopter
Serial number
1113
Airframe hours
5,292
Engine
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.

Role
Pilot
Age
39
Certificates
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.