Aviation Accident Summaries

Aviation Accident Summary ANC99LA140

JUNEAU, AK, USA

Aircraft #1

N6052C

Eurocopter AS-350B-2

Analysis

The commercial helicopter pilot, with one passenger aboard, was conducting a search for an overdue company helicopter. While searching the upper portion of a glacial ice field, deteriorating weather conditions required the pilot to alter his search route. He said that he slowed the helicopter to 15 knots and attempted to use a mountain range on the right side of the helicopter for visual reference. He said: 'Visibility in front was enough to see all the way to the top of the Herbert (greater than three miles). The ceiling sloped down to the east 45 degrees with a height at the ridge of approximately 700 feet.' The pilot added that just seconds before the impact, he thought the helicopter was at least 500 feet above the surface. He said that 'flat light conditions' made it very difficult to see the topographical features of the ice field below. The helicopter struck the snow-covered ice field, slid about 75 feet, and the helicopter rolled over to the right. The helicopter sustained substantial damage to the fuselage, tail boom, and rotor system. After the accident, the pilot radioed for another company helicopter to pick them up. A second company helicopter, N6099Y, landed at the accident site, boarded the uninjured pilot and passenger, and continued the search. During the search, N6099Y also collided with the snow-covered ice field. See ANC99FA139, and ANC99LA141. The accident pilot did not possess an instrument rating, and the helicopter was not equipped with a radar altimeter.

Factual Information

On September 10, 1999, about 1445 Alaska daylight time, a Eurocopter AS-350B-2 helicopter, N6052C, sustained substantial damage when it impacted the surface of the Juneau ice field, about 17 miles north of Juneau, Alaska, at 58.37.646 north latitude, 134.28.270 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 one passenger 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 1345 from the Juneau International Airport, Juneau. During an interview with the National Transportation Safety Board investigator-in-charge on September 11, the pilot reported that he was conducting a search for an overdue company helicopter. The pilot said that while searching the upper portion of the ice field, deteriorating weather conditions to the north and east required that he proceed south, and down the ice field. He stated that he slowed the helicopter to 15 knots and attempted to use a mountain range on the right side of the helicopter for visual reference. He said: "Visibility in front was enough to see all the way to the top of the Herbert (greater than three miles). The ceiling sloped down to the east 45 degrees with a height at the ridge of approximately 700 feet." The pilot added that just seconds before the impact, he thought the helicopter was at least 500 feet above the surface. He said that "flat light conditions" made it very difficult to see the topographical features of the ice field below. The helicopter struck the snow-covered ice field, slid about 75 feet, and the helicopter rolled over to the right. The helicopter sustained substantial damage to the fuselage, tail boom, and rotor system. After the accident, the pilot radioed for another company helicopter to pick them up. A second company helicopter, N6099Y, landed at the accident site, boarded the uninjured pilot and passenger, and continued the search. During the search, N6099Y also collided with the snow-covered ice field. See ANC99FA139, and ANC99LA141. The accident pilot did not possess an instrument rating, and the helicopter was not equipped with a radar altimeter.

Probable Cause and Findings

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.

 

Source: NTSB Aviation Accident Database

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