Skagway, AK, USA
N94TH
AIRBUS AS350
The non-instrument-rated commercial pilot was making a visual flight rules internal-cargo company flight in the helicopter. He was returning to base in the helicopter after dropping off 1 employee and 12 dogs at a remote dog camp situated on a glacier surrounded by mountainous terrain. The pilot had previously completed 5 of the day's 7 planned roundtrip flights from the base to the dog camp. According to the dog camp manager, the weather was deteriorating with snow and wind increasing when the pilot departed on the accident flight. The dog camp manager's observations and radar data indicated that the pilot attempted to depart via the normal route to the south but turned around. He likely encountered low visibility conditions and then attempted several departures by routes to the north of the dog camp. About 8 minutes after departure, the helicopter impacted snow-covered mountainous terrain about 2 miles northeast of the dog camp. Postaccident examination of the helicopter revealed no evidence of preimpact mechanical anomalies that would have precluded normal operation. Given the deteriorating weather conditions when the pilot departed, it is likely that the pilot continued visual flight into an area of instrument meteorological conditions, which resulted in the pilot experiencing a loss of visual reference and subsequent controlled flight into terrain. During the impact sequence, the two cargo straps used to secure two wooden dog boxes to the rear cabin floor failed, and the dog boxes shifted forward, striking the back of the pilot's fiberglass seat. It could not be determined if the forward movement of the dog boxes during the accident sequence contributed to the injuries sustained by the pilot. Immediately before departing from the dog camp on the accident flight, the pilot told the dog camp manager that, due to the degrading weather conditions, he would not be coming back for the last scheduled trip of the day, and the dog camp manager told the pilot that he agreed with him. However, the pilot then told the dog camp manager, "but don't give up on me yet," a statement consistent with self-induced pressure to complete the day's series of flights. On one of the day's previous flights, the pilot reported to the base manager, who was exercising operational control at the time of the accident, that he had encountered icing conditions while in flight. The base manager told the pilot "to do what he thought was best." However, flight operations in icing conditions are prohibited by the helicopter's rotorcraft flight manual and the operator's operations manual, and the pilot's statement should have prompted the base manager to suspend the flights. If flight operations had been cancelled for the day when the pilot reported the icing conditions, the subsequent flights, including the accident flight, would not have occurred. The base manager's failure to appropriately exercise operational control and terminate the flights may have been due to the difference in experience between the base manager, who had been operating these flights for 8 years, and the pilot, who had been operating these flights for 25 years.
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 manager, age 30, held a commercial pilot certificate with a rotorcraft-helicopter and instrument helicopter rating. His total aeronautical experience was about 3,445 hours, and this was his eighth season with TEMSCO. All of his eight seasons were in Skagway. AIRCRAFT INFORMATIONThe 1991-model-year helicopter was equipped with a Safran (formerly Turbomeca) Arriel 1D1 turboshaft engine. According to the operator's records, at the time of the accident, the helicopter had accumulated 10,190.5 flight hours, and the engine had accumulated 4,281.6 hours. The most recent inspection of the airframe and engine was completed on December 17, 2015. An examination of the helicopter's maintenance records revealed no evidence of uncorrected mechanical discrepancies with the airframe and engine. The helicopter was originally manufactured as an AS 350 B and was converted to an AS 350 BA in 1992 and then to an AS 350 B2 in 2003. The helicopter was configured to be flown from the right front seat, which was a non-energy attenuating, fiberglass seat. The left front seat that was installed in the helicopter was a single-place, non-energy attenuating, fiberglass seat. The helicopter was not equipped with a radar altimeter, nor was it required to be at the time of the accident. The helicopter was equipped with a Federal Aviation Administration (FAA) Capstone Project avionics package. The skid system of the helicopter included snow/tundra boards mounted on the aft ends of both skid tubes along with an emergency floatation system on both skid tubes. TEMSCO configured the helicopter cabin to facilitate the transportation of internal cargo. The rear seat assembly was folded up against the cabin wall, and two wood, dog transportation boxes were placed behind the front seats. A tarp, blanket, and wood shoring were placed between the lower box and the cabin floor. The dog boxes were stacked vertically and secured using two cargo straps attached to a total of four seat belt attachment rings installed on the floor of the cabin. Both cargo straps were secured to the rear seat belt attachment points in front of the aft cabin wall, routed over the top of the stacked boxes, and secured to the pilot and front passenger seat belt attachment points. With the configuration of the two cargo straps, forward restraint was present; however, no lateral restraint was present. Neither dog box had a placarded weight value on the outside of it. The make and model of the cargo straps, as well as the maximum load rating of the straps, could not be determined. The two cargo straps had abrasions at various locations along with unknown stains throughout the length of the straps. The Airbus AS 350 B2 rotorcraft flight manual (RFM) discusses required placards in the limitations section and states that a loading instruction placard is to be mounted on the side face of the control pedestal. On the accident helicopter, the placard was found mounted on the rear of the control pedestal. This placard listed the "distributed loads maximum" for the rear cabin floor as 682 pounds. The combined weight of the two wood dog boxes was 190.5 pounds; the wood boards used for shoring on the cabin floor weighed 9.5 pounds; and the blanket, tarp, and two cargo straps weighed 5 pounds. The total weight of 205 pounds was not included on the cargo manifest documents for the day's flights or the helicopter's weight and balance record. On each of the first four flights from Skagway to the dog camp, the total dog weight entered on the cargo manifest form was 500 pounds (10 dogs on board). On the fifth flight, the dog weight entered was 550 pounds (11 dogs on board). On the sixth flight, the dog weight entered was 600 pounds (12 dogs on board). For all six flights from Skagway to the dog camp, the weight of the dog boxes and related items (205 pounds) combined with the dog weight resulted in the structural limitation of 682 pounds being exceeded. METEOROLOGICAL INFORMATIONThe closest official weather observation station to the accident site was located at the Skagway Airport, Skagway, about 4 miles northwest of the accident site. At 1853, the reported weather conditions were wind 210° at 19 knots gusting to 28 knots, visibility 10 statute miles, few clouds at 8,000 ft, temperature 53°F, dew point 37°F, and altimeter setting 29.81 inches of mercury. Refer to the Meteorology Group Chairman's Factual Report in the public docket for further weather information. AIRPORT INFORMATIONThe 1991-model-year helicopter was equipped with a Safran (formerly Turbomeca) Arriel 1D1 turboshaft engine. According to the operator's records, at the time of the accident, the helicopter had accumulated 10,190.5 flight hours, and the engine had accumulated 4,281.6 hours. The most recent inspection of the airframe and engine was completed on December 17, 2015. An examination of the helicopter's maintenance records revealed no evidence of uncorrected mechanical discrepancies with the airframe and engine. The helicopter was originally manufactured as an AS 350 B and was converted to an AS 350 BA in 1992 and then to an AS 350 B2 in 2003. The helicopter was configured to be flown from the right front seat, which was a non-energy attenuating, fiberglass seat. The left front seat that was installed in the helicopter was a single-place, non-energy attenuating, fiberglass seat. The helicopter was not equipped with a radar altimeter, nor was it required to be at the time of the accident. The helicopter was equipped with a Federal Aviation Administration (FAA) Capstone Project avionics package. The skid system of the helicopter included snow/tundra boards mounted on the aft ends of both skid tubes along with an emergency floatation system on both skid tubes. TEMSCO configured the helicopter cabin to facilitate the transportation of internal cargo. The rear seat assembly was folded up against the cabin wall, and two wood, dog transportation boxes were placed behind the front seats. A tarp, blanket, and wood shoring were placed between the lower box and the cabin floor. The dog boxes were stacked vertically and secured using two cargo straps attached to a total of four seat belt attachment rings installed on the floor of the cabin. Both cargo straps were secured to the rear seat belt attachment points in front of
The pilot's decision to continue visual flight into an area of instrument meteorological conditions, which resulted in the pilot experiencing a loss of visual reference and subsequent controlled flight into terrain. Contributing to the accident were the pilot's self-induced pressure to complete the flight and the operator's failure to maintain operational control over the flight.
Source: NTSB Aviation Accident Database
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