N94TH

HISTORY OF FLIGHTOn May 6, 2016, about 1900 Alaska daylight time, an Airbus (formerly Eurocopter) AS 350 B2 helicopter, N94TH, collided with snow-covered mountainous terrain about 4 miles southeast of Skagway, Alaska, after departing from a remote landing site on the Denver Glacier. The commercial pilot received fatal injuries, and the helicopter sustained substantial damage. The helicopter was registered to and operated by TEMSCO Helicopters, Inc., Ketchikan, Alaska, under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 as a visual flight rules (VFR) internal-cargo company flight. Instrument meteorological conditions were reported on the Denver Glacier at the time of the accident, and company flight following procedures were in effect. The flight originated from a heliport at the operator's headquarters in Skagway about 1840, landed at the remote site for several minutes, and departed for the return flight about 1852.

Alaska Icefield Expeditions, Inc., contracted with TEMSCO to provide helicopter support for the movement of personnel, dogs, and cargo. The purpose of the flight was to transport dog camp company personnel (mushers) and dogs (Alaskan Huskies) from the operator's headquarters in Skagway to a remote dog camp on the Denver Glacier in the Tongass National Forest, about 5 miles southeast of Skagway. TEMSCO and Alaska Icefield Expeditions conducted heli-mushing operations for the Alaska tourism industry using a helicopter glacier landing permit issued by the US Forest Service.

The pilot was scheduled for seven continuous roundtrip flights (without shutting down the helicopter) to the dog camp on the day of the accident. All flights scheduled for the day of the accident fell under the operational control of the base manager, who was located at TEMSCO's headquarters in Skagway. The pilot was ready to begin flight operations at 0800, but low ceilings prevented flight operations. The pilot attended company orientation training at 0900, and, at 1300, he provided helicopter loading training for new TEMSCO employees. At 1530, the pilot completed the training and evaluated the weather for flight operations. The pilot determined that the wind conditions were unsuitable at the time but were forecasted to improve later in the afternoon.

The dog camp manager, who was located at the dog camp on the Denver Glacier, was responsible for managing operations of the dog camp. He reported that, on the day of the accident, from about 0600 to 1200, the weather in the dog camp was cloudy, snowing, and foggy, and the visibility was "a few hundred yards." At 1200, the clouds broke, the snow stopped, and visibility was such that he could see through Paradise Valley across the Taiya Inlet. He reported that flight operations were cancelled because of the wind; the wind on the glacier was between 10 and 15 mph. About 1630, TEMSCO informed the dog camp manager, that flight operations would begin to deliver mushers and dogs to the camp.

At 1645, the wind speed had dropped significantly at the base, and the pilot decided it was safe to launch. The pilot completed two roundtrips, each with 1 musher and 10 dogs on board the helicopter. The dog camp manager stated that it was snowing as these flights arrived. At 1738, the pilot called inbound from the Denver Glacier to the base, and the base manager asked the pilot about the weather conditions. The pilot reported to the base manger that there was turbulence around the toe of the glacier and that he was keeping his airspeed down for a smoother ride. Based on the pilot's report, the base manager decided to cancel a scheduled external load flight that he had planned to fly and load the cargo internally in another helicopter.

At 1747, the helicopter departed from the base for the third trip, again with 1 musher and 10 dogs onboard. En route to the glacier, the pilot reported to the base manager that he "experienced a little bit of inflight icing" at 3,000 ft mean sea level (msl). The base manager asked the pilot what kind of precipitation he was experiencing, and the pilot reported "wet snow." The base manager told the pilot "to do what he thought was best." The pilot responded that he would evaluate the icing conditions as he flew on the subsequent flights. The fourth and fifth roundtrips were completed uneventfully; the fourth carried 1 musher and 10 dogs, and the fifth carried 1 musher and 11 dogs.

At 1840, the helicopter departed for the sixth trip with 1 musher and 12 dogs onboard. As the helicopter passed through Paradise Valley, the passenger reported that the valley itself was "wide open" with a rainbow present, but he and the pilot could see that the clouds were "moving in" as the helicopter approached the Denver Glacier. The passenger reported that the clouds were "thick," and he could not see up the glacier toward the dog camp. The passenger further reported that the western mountain wall near the glacier was visible at the time, so the pilot elected to follow the wall into the dog camp "very slowly." He stated that the helicopter was "very low" with regard to the bluff and was closer to the wall than he had ever been on previous flights up to the dog camp. The dog camp manager reported that just before the sixth flight arrived, the wind speed was up to 20 to 30 mph, and it was snowing. The clouds had moved in and covered the bluff; visibility was about a 1/4 mile looking toward Paradise Valley. The helicopter landed at the dog camp, and the musher and 12 dogs were unloaded.

Before the pilot left, he signaled for the dog camp manager and told him that he was "not coming back in this weather." The dog camp manager verbally agreed. The dog camp manager told the pilot to be safe, and the pilot said to the dog camp manager, "but don't give up on me yet." The pilot then departed from the dog camp at 1852 and headed toward Paradise Valley.

According to the dog camp manager, the helicopter traveled about 1/8 mile toward Paradise Valley, turned around, and then turned north. The dog camp manager reported that the visibility looking north from the dog camp appeared to be about 1/4 mile. He noticed that the snow rate had picked up "considerably," and the wind speed was still between 20 and 30 mph.

A review of Harris OpsVue track data was conducted during the timeframe of 1815 to 1915. The OpsVue data indicated the accident helicopter was making multiple 360° turns before turning to the north and east and continuing to make turns. As the helicopter was tracking toward the east, the altitude was trending up in a slow climb before descending near the accident site.

About 1900, the TEMSCO base manager noted that he had not heard any communication on the radio for a few minutes, so he asked about the status of the accident helicopter and noticed on the flight tracking computer that the helicopter's position was northwest of the dog camp at an elevation of about 6,200 ft msl, about 2,000 ft above the dog camp's elevation. He made several radio calls to the pilot, and no responses were received. After repeated radio calls with no response from the pilot, the base manager decided to launch in a helicopter with an observer on onboard. The company emergency response plan was activated. At 1914, the base manager departed to the last known coordinates of the missing helicopter. The base manager reported that he was unable to fly over the dog camp via Paradise Valley at 1924 due to low ceilings, blowing snow, and turbulence.

At 1942, the base manager reported that he was maneuvering near the North Denver Icefall area, and he was unable to climb higher than 4,000 ft msl due to low ceilings, blowing snow, and "mechanical" turbulence. By 1948, the base manager reported "improving" ceilings and being able to maneuver around 5,000 ft msl. At 2009, the base manager and observer visually confirmed the wreckage of the accident helicopter lying on its left side with the tailboom separated in steep, mountainous terrain near a frozen glacial lake, about 2 miles northeast of the dog camp.

After the base manger confirmed the location of the wreckage, he asked if the dog camp personnel could travel to the wreckage site. The dog camp manager and several other workers rode two snow machines toward the wreckage; they noted the wind speed was between 30 and 40 mph and visibility was between zero and "a few hundred feet" in blowing snow. As they proceeded toward the wreckage, the wind speed increased to between 50 and 70 mph. The dog camp personnel were unable to proceed any farther due to the steep terrain and the possibility of avalanches.

The base manager attempted multiple times to land at the accident site but was unable to land due to high wind and flat light conditions. About 2200, a US Coast Guard helicopter attempted to access the accident site but was unsuccessful due to the wind conditions. After dumping fuel, the Coast Guard helicopter was able to access the accident site, and an aviation survival technician (helicopter rescue swimmer) confirmed one fatality in the wreckage. PERSONNEL INFORMATIONThe pilot, age 66, held a commercial pilot certificate with a rotorcraft-helicopter rating and held private pilot privileges for airplane single-engine land. The pilot did not have and was not required to have a helicopter instrument rating. His most recent second-class medical certificate was issued on February 27, 2016, with the limitation that he must wear corrective lenses.

According to the operator, the pilot's total aeronautical experience was about 7,190 hours of which about 5,700 hours were in the accident helicopter make and model. In the 90 and 30 days before the accident, the pilot flew 5 and 3 flight hours, respectively. This was his 25th season with TEMSCO.

The operator's pilot training records showed no deficiencies and indicated that the pilot had completed all required training, including a competency check ride on March 19, 2016.

The Skagway base manag...