ANC17LA011

The commercial pilot of the helicopter stated that the purpose of the flight was to transport a telecommunications technician to a cattle ranch on an island. After departing from the airport, while flying overwater, the pilot observed a snow squall with near-zero visibility and decided to return to the airport. On the return trip, while flying in a mountainous valley, another snow squall moved into the area. He stated that due to the deteriorating flight conditions, he conducted a precautionary landing to remote, snow-covered terrain to wait for improved flight conditions. Once the squall passed, he continued to the airport. Several minutes later, another snow squall arrived, and the pilot decided to conduct another precautionary landing. During the landing sequence, the main rotor system downwash resulted in whiteout conditions, and the pilot was unable to recognize any topographical features. The main rotor blades impacted terrain and the helicopter rolled onto its left side. The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.

On December 2, 2016, about 1200 Alaska standard time, a Robinson R-22 Beta helicopter, N7085K, collided with remote snow-covered terrain while landing, about 10 miles southwest of Unalaska, Alaska. The commercial pilot sustained no injury, the passenger sustained minor injuries, and the helicopter sustained substantial damage. The helicopter was registered to, and operated by, Bering Pacific Ranches Ltd., Calgary, Alberta, Canada, as a visual flight rules (VFR) flight under the provisions of 14 Code of Federal Regulations Part 91. Deteriorating visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The flight originated from the Unalaska Airport, Unalaska, about 1100. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on December 7, the pilot stated that the purpose of the flight was to transport a telecommunications technician to the Fort Glenn cattle ranch on Umnak Island. After departing from the Unalaska Airport, while flying overwater past Makushin Bay near Cape Starichkof, he observed a snow squall with near zero visibility. The pilot decided to return to Unalaska. On the return trip, while flying in a mountainous valley, a snow squall moved into the area. He stated that due to the deteriorating flight conditions, he conducted a precautionary landing to remote snow-covered terrain to wait for improved flight conditions. Once the snow squall passed, he departed to head back to Unalaska. Several minutes later, he encountered a second snow squall and decided to conduct another precautionary landing. During the precautionary landing sequence, whiteout conditions were present from the main rotor system downwash from the previous snow squall, and the pilot was unable to recognize any topographical features. The main rotor blades impacted terrain and the helicopter rolled onto its left side. Both occupants egressed from the wreckage, a personal locator beacon was activated, and the occupants were extracted from the accident site via a U.S. Coast Guard MH-65D helicopter. The helicopter sustained substantial damage to the fuselage, main rotor system, tail boom, and tail rotor system. The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. PERSONNEL INFORMATION In the NTSB Accident/Incident Reporting Form 6120.1, the pilot reported that he held a helicopter instrument rating in addition to instructor ratings for helicopter and instrument helicopter. He additionally reported 70 hours of simulated instrument flight time and no hours were reported for actual instrument flight time. AIRCRAFT INFORMATION The helicopter had no onboard weather capability and it was not instrument flight rules-equipped and certified. The helicopter had a standard skid configuration with no emergency floatation system installed. METEOROLOGICAL INFORMATION The closestofficial weather observation station is located at the Unalaska Airport, about 10 miles northeast of the accident site. At 1200, an Aviation Routine Weather Report (METAR) was reporting, in part: wind 220° (true) at 18 knots, gusting 25 knots; visibility 10 statute miles; clouds and sky condition, broken clouds at 1,600 feet; temperature 37° F; dew point 27° F; altimeter 30.19 inHg. SURVIVAL ASPECTS The accident helicopter was not equipped, nor was it required to be equipped with an emergency locator transmitter. The pilot and passenger were not wearing flight helmets for the flight. The helicopter was equipped with 3-point restraint systems for the two seats. ADDITIONAL INFORMATION The Naval Research Laboratory has published the Forecaster's Handbook for the Bering Sea, Aleutian Islands, and Gulf of Alaska (1993). This document discusses snowfall and snow cover on the Aleutian Islands and states in part: During winter, snow frequently covers the ground but the depth of coverage rarely exceeds 1 foot (30 centimeters). High winds, however, cause snow to drift so that depth at an individual location is highly dependent on topography. Some depressions may fill to depths exceeding 6 feet (1.8 meters), and other areas remain relatively free of snow. Because of the relatively mild temperatures, the snow is frequently of the wet, heavy type. Annual rainfall for the islands averages 40 to 50 inches (102 to 152 centimeters), and, again is heavily influenced by topography so that individual locations may have quite different rainfall amounts even though they are separated by only a short distance.