ANC99LA141

NTSB accident investigation · Eurocopter AS-350B-2 · Juneau, AK · September 11, 1999

Accident · No injuriesLimited investigationFinal report
Date
September 10, 1999, 16:30 local (Sep 11, 1999, 00:30 UTC)
Place
Juneau, AK
Injuries
4 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N6099YEurocopter AS-350B-2
Weather
Visual (VMC) · Day
Status
Completed · report August 10, 2000
Report
Approved by Office Director
NTSB office
Alaska Regional Office
FAA report
19990910046629A
Case key
47402

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

The pilot's failure to maintain altitude/clearance. Factors associated with the accident were flat light conditions, snow-covered terrain, and self-induced pressure to continue the search.

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.

In flight collision with terrain/waterCruise
Altitude/clearance - not maintainedPilot in commandCause
Self-induced pressurePilot in commandFactor
Light condition - otherFactor
Terrain condition - snow coveredFactor

Analysis

The commercial helicopter pilot, with one passenger aboard, was en route from Petersburg to Juneau, when he was requested to join a search for an overdue company helicopter (N6007S). He said that just after entering the search area, he received a radio transmission from another company helicopter (N6052C), who was also involved in the search. The pilot of N6052C informed him that he had crashed on the ice field, and required assistance. The pilot of N6099Y stated that poor weather conditions in the vicinity N6052C would not allow the him to land, so he elected to return to the airport for fuel, and wait for better weather conditions. After refueling, he returned to the accident site of N6052C, where weather conditions had improved. After landing, the uninjured pilot and passenger boarded N6099Y, and all aboard agreed to continue the search for N6007S. The pilot of N6099Y stated that he was able to locate the downed helicopter about two miles directly in front of his location. He said that he slowed the helicopter to about 30 knots in an attempt to gain reference using a mountain range on the left side of the helicopter, and the accident site of N6007S. He said: 'The ceiling at my location was at least 1,000 feet agl, and visibility towards 07S was more than six miles. Just before the impact, I was sure I was at least 500 feet agl.' The pilot added that 'flat light conditions' hampered his ability to see the topographical features of the ice field below. The helicopter struck the snow-covered ice field, slid about 50 feet, nosed over, and rolled to the left. The helicopter sustained substantial damage to the fuselage, tail boom, and rotor system. The accident helicopter was not equipped with a radar altimeter.

Factual narrative

On September 10, 1999, about 1630 Alaska daylight time, a Eurocopter AS-350B-2 helicopter, N6099Y, sustained substantial damage when it impacted the surface of the Juneau ice field, about 18 miles north of Juneau, Alaska, at 58.37.809 north latitude, 134.32.310 west longitude. The helicopter was being operated as a visual flight rules (VFR) search and rescue flight under Title 14, CFR Part 91, when the accident occurred. The helicopter was operated by Temsco Helicopters, Inc., Ketchikan, Alaska. The certificated commercial pilot and the three passengers aboard were not injured. Visual meteorological conditions prevailed at the time of departure, and company flight following procedures were in effect. The flight originated about 1530 from the Juneau Airport.

During an interview with the National Transportation Safety Board investigator-in-charge on September 11, the pilot reported that he and his sole passenger were en route from Petersburg to Juneau, when he was requested to join a search for an overdue company helicopter (N6007S). He said that just after entering the search area, about 1530, he received a radio transmission from the pilot of another company helicopter (N6052C), who was also involved in the search. The pilot of N6052C informed him that he had crashed on the ice field, and required assistance.

The pilot of N6099Y stated that poor weather conditions in the vicinity N6052C would not allow the him to land, so he elected to return to the Juneau Airport for fuel, and wait for better weather conditions. After refueling, about 1600, he departed Juneau, and returned to the accident site of N6052C, where weather conditions had now improved. After landing, the uninjured pilot and passenger boarded N6099Y. He said that after being assured that both occupants of N6052C were uninjured, all aboard agreed to continue the search for N6007S. (See ANC99FA139, and ANC99LA140)

The pilot reported that during their resumed search, other search helicopters reported the position of the original missing helicopter, and N6099Y proceeded to the reported accident location of N6099Y.

The pilot of N6099Y stated to the National Transportation Safety Board investigator-in-charge, that he was able to locate the downed helicopter about two miles directly in front of his location. He said that he slowed the helicopter to about 30 knots in an attempt to gain reference using a mountain range on the left side of the helicopter, and the accident site of N6007S. He said: "The ceiling at my location was at least 1,000 feet agl, and visibility towards 07S was more than six miles. Just before the impact, I was sure I was at least 500 feet agl." The pilot added that "flat light conditions" hampered his ability to see the topographical features of the ice field below. The helicopter struck the snow-covered ice field, slid about 50 feet, nosed over, and rolled to the left.

The helicopter sustained substantial damage to the fuselage, tail boom, and rotor system.

The accident pilot did possess an instrument rating for rotorcraft, but had not obtained any instrument competency checks or training since 1995, while being employed by the operator.

The accident helicopter was not equipped with a radar altimeter.

Aircraft

Registration
N6099Y
Reported as
Eurocopter AS-350B-2
Category
Helicopter
Serial number
2847
Airframe hours
2,063
Engine
Turbomeca ARRIEL 1D1, 731 horsepower, turbo shaft
Damage
Substantial damage
Flight
Part 91
Registered owner
Temsco Helicopters, Inc.
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · August 15, 1999 · 56 hours before
Departed
JUN · AK
Flight plan
Company VFR

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
31
Certificate
Commercial
Instrument ratings
Helicopter
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
4,100 total · 1,250 in this make and model · 4,000 as pilot in command · 213 in the last 90 days · 80 in the last 30 days · 3 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
180° at 10 knots, gusting 15
Visibility
6 statute miles
Lowest ceiling
500 ft overcast
Temperature
32 °F

Docket · 2

The files NTSB released with the investigation on July 28, 2000, on NTSB’s docket system: statements, records, photos and specialists’ reports. 745 KB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.