# NTSB ANC06TA047: American Eurocopter AS350 B3, N911AA, Nikiski, AK, April 21, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: April 21, 2006, 01:06 local (09:06 UTC) - Place: Nikiski, AK - Coordinates: 61.433055, -151.644729 - Nearby events: https://openairdocs.org/map.md?lat=61.4331&lon=-151.6447&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report April 25, 2007 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 63568 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC06TA047 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/63568/pdf - Page: https://openairdocs.org/ntsb/ANC06TA047 ## Probable cause The pilot's failure to maintain adequate altitude/clearance from terrain during an aborted takeoff in whiteout conditions, which resulted in an in-flight collision with terrain. A factor associated with the accident was whiteout conditions. ## Analysis The airline transport certificated pilot was transporting an Alaska State Trooper, and a rescue volunteer with their equipment, to a remote lodge to search for a missing person. The flight was conducted during dark night conditions, and the pilot was using night vision goggles (NVG) to help discern topographical features on the snow-covered terrain. After an uneventful outbound flight to the lodge, the pilot landed the helicopter on a frozen lake adjacent to the lodge. During an hour-long search of the lodge and surrounding outbuildings, snow fell, with a light accumulation on the frozen lake where the accident helicopter was parked. Unable to locate the missing person, the search team boarded the helicopter for the return flight, and the pilot donned his NVGs. Just after takeoff, as the helicopter transitioned from a hover to forward flight, blowing snow from the helicopter's main rotor momentarily reduced the pilot's visibility, and he lost all visual reference with the surface of the frozen lake. While he was attempting to regain a visual reference, the helicopter's tail rotor guard and vertical stabilizer struck the surface of the lake, and he elected to abort the takeoff. The helicopter's skids subsequently struck the surface of the ice, and the helicopter bounced several times before stopping. A postaccident inspection revealed substantial damage to the helicopter's vertical stabilizer, tail boom assembly, and fuselage. The pilot reported that there were no preaccident mechanical anomalies with the helicopter, and that he had not received any formal training in the use of NVG's. ## Factual narrative On April 21, 2006, about 0106 Alaska daylight time, a high skid-equipped American Eurocopter AS350 B3 helicopter, N911AA, sustained substantial damage during takeoff from a remote area, about 30 miles northwest of Nikiski, Alaska. The helicopter was being operated as a visual flight rules (VFR) government-operated flight under Title 14, CFR Part 91, when the accident occurred. The helicopter was operated by the State of Alaska, Department of Public Safety. The airline transport certificated pilot, and the two passengers, were not injured. Dark night visual meteorological conditions prevailed, and company flight following procedures were in effect. The accident flight originated at the Big River Lakes Lodge about 0106, and was en route to Soldotna, Alaska. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on April 27, the pilot reported that he was transporting an Alaska State Trooper, and a rescue volunteer with their equipment to the Big River Lakes Lodge to search for a missing person. The accident pilot reported that due to dark night conditions and the lack of ground based light sources while flying over unpopulated terrain, he was using a pair of night vision goggles (NVG) to help discern topographical features. He said that after an uneventful outbound flight to the lodge, he landed the helicopter on a frozen lake adjacent to the lodge. The search team subsequently conducted an hour-long search of the lodge and surrounding outbuildings. He said that during the search, snow fell, with a light accumulation of snow on the frozen lake where the accident helicopter was parked. Unable to locate the missing person, the search team boarded the helicopter for the flight to the Alaska State Trooper's post in Soldotna. Before takeoff, the pilot donned his NVGs. He said that just after takeoff, as the helicopter transitioned from a hover to forward flight, blowing snow from the helicopter's main rotor momentarily reduced his visibility, and he lost all visual reference with the surface of the frozen lake. He reported that while attempting to regain a visual reference, the helicopter's tail rotor guard and vertical stabilizer struck the surface of the lake, and he elected to abort the takeoff and attempt a run-on landing. The helicopter's skids subsequently struck the surface of the ice, and the helicopter bounced several times before stopping. A postaccident inspection revealed substantial damage to the helicopter's vertical stabilizer, tail boom assembly, and fuselage. The pilot reported that there were no preaccident mechanical anomalies with the helicopter. During the April 27 telephone conversation with the NTSB IIC, the pilot said that at the time of the accident the State of Alaska Department of Public Safety was not utilizing a formal, or a Federal Aviation Administration (FAA) approved NVG training program. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, takeoff - aborted - altitude/clearance - not maintained, pilot in command (cause) - weather condition - whiteout (contributing factor) - weather condition - snow - light condition - dark night - inadequate initial training, company/operator management - terrain condition - snow covered ## Aircraft - Registration: [N911AA](https://openairdocs.org/deregistered/N911AA-2013-06-13), registration cancelled 2013-06-13, S/N 3611, built 2002 (OpenAirDocs) - Reported make and model: American Eurocopter AS350 B3 - Registry model: [Eurocopter AS 350 B3](https://openairdocs.org/model/eurocopter-as-350-b3) (registry code 8680954) (OpenAirDocs) - Registry engine: [Turbomeca ARRIEL-2B1](https://openairdocs.org/engine/turbomeca-arriel-2b1) (registry code 60056, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 3611 - Airframe hours: 967.6 - Engines: Turbomeca Arriel 2B 847 horsepower turbo shaft - Damage: Substantial damage - Flight: Public aircraft, Part 91 - Registered owner: State of Alaska, Department of Public Safety - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, March 1, 2006, 29.2 hours before - Departed: Nikiski, AK - Destination: Soldotna, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; commercial, flight instructor, airline transport; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, with waivers/limitations; last flight review July 1, 2005; seat: right; flight hours: 9,000 total, 950 in this make and model, 8,715 as pilot in command, 70 in the last 90 days, 29 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: calm - Visibility: 2 statute miles - Lowest ceiling: 800 ft overcast - Temperature: 86 °F ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20060421006519A](https://openairdocs.org/incident/20060421006519A), Apr 21, 2006: Snias AS350B3, Kenai, AK, Substantial damage. (-23) The pilot and two Alaska state troopers were on a search mission for a reported missing person. The pilot was using night vision goggles when the… ## Other investigations on N911AA (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB ANC13GA036](https://openairdocs.org/ntsb/ANC13GA036), Mar 31, 2013: Eurocopter AS350 (N911AA), Talkeetna, AK, destroyed, 3 fatal. Probable cause: The pilot's decision to continue flight under visual flight rules into deteriorating weather conditions, which resulted in the pilot's spatial disorientation and loss of control. Also causal was the… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.