History of Flight
On October 29, 2011, at approximately 2009 Alaska daylight time, a Eurocopter AS350-B2 helicopter, registration N165EH, was destroyed when it collided with tundra-covered terrain about 7 miles southwest of Iliamna, Alaska. The pilot, the only occupant, died at the scene. The helicopter was operated by ERA Helicopters LLC under 14 CFR Part 135 as a visual flight rules (VFR) on-demand charter flight. Dark night and visual meteorological conditions prevailed at the Iliamna Airport at the time. The flight originated in Nome, Alaska at about 1343, with fuel stops in Unalakleet and Bethel before continuing to Iliamna. Company VFR flight following procedures were in effect.
The helicopter was under contract to Fugro Airborne Surveys to support an aerial seismic survey project near Nome. The survey crew had completed their work and returned to Anchorage on October 25. The pilot planned to rendezvous with the crew to remove specialized survey equipment still installed in the helicopter, but poor weather delayed his departure from Nome until the afternoon of October 29.
The helicopter was equipped with a Sky Connect satellite tracking system that provided real-time position reports about every minute and satellite phone communication. Archived flight track data showed that after refueling in Bethel, the helicopter departed at about 1755 en route to Iliamna. As the flight progressed eastward along the northern shore of Iliamna Lake, the Sky Connect signal was lost at 2008, about 8 miles southwest of Iliamna. Subsequent attempts to contact the helicopter were unsuccessful.
The Federal Aviation Administration (FAA) issued an alert notice (ALNOT) on October 30 at 0615 Alaska daylight time. The following morning, the crew of a company-owned Bell 212 helicopter discovered the fragmented wreckage about 7 miles southwest of Iliamna in an area of marshy, tundra-covered terrain.
Fuel vendors in Unalakleet and Bethel noted that the pilot seemed rushed and mentioned trying to get to Iliamna before dark. Sunset on the day of the accident was 1833; the end of civil twilight was 1917.
Aircraft Information
The helicopter was a Eurocopter AS350-B2 equipped with a Turbomeca Arriel 1D1 turboshaft engine. It was maintained under the operator's Approved Aircraft Inspection Program (AAIP), which requires inspections approximately every 100 flight hours. At departure from Nome, the helicopter had 9,124.6 flight hours, and about 35 hours had elapsed since the most recent phase inspection. The operator estimated that the pilot flew about 5 hours on the day of the accident.
Wreckage and Impact Information
The NTSB investigator-in-charge, along with representatives from ERA Helicopters, Eurocopter USA, Turbomeca USA, and the FAA Anchorage Flight Standards District Office, attempted to reach the accident site by helicopter but were delayed by continuous poor weather until November 1. By then, the area had received about 6 inches of snow, blanketing the wreckage.
The main debris path was oriented on a 040-degree magnetic heading and was about 195 feet long. About 180 feet southwest of the main wreckage was a crater measuring 4 feet in diameter and 3 feet deep, believed to be the initial impact point. The pilot's chin bubble-mounted cargo mirror and the toe of the right skid were found in the crater. Debris between the crater and main wreckage included plexiglas, aluminum, door frame assembly, and main rotor blade fragments. All major components were located at the main wreckage site, but extensive fragmentation prevented establishing flight control continuity. The tail boom was separated from the fuselage at the forward attachment point. No preaccident mechanical anomalies were noted. The emergency locator transmitter (ELT) housing remained attached to the mounting bracket, which separated from the fuselage; the ELT sustained considerable fire damage.
Meteorological Information
The closest weather reporting facility was Iliamna Airport, 7 miles northeast of the accident site. At 1953, about 11 minutes before the accident, a METAR reported wind 280 degrees true at 6 knots, visibility 5 statute miles with light snow, overcast ceiling at 3,100 feet, temperature 36°F, dew point 27°F, altimeter 29.28 inHg. At 2020, about 11 minutes after the accident, a special observation reported wind 300 degrees at 9 knots, visibility 1.5 statute miles with light snow, broken clouds at 2,000 feet and overcast at 3,100 feet.
Medical and Pathological Information
A postmortem examination conducted under the authority of the Alaska State Medical Examiner attributed the pilot's death to blunt force traumatic injuries. Toxicological tests performed by the FAA's Civil Aeromedical Institute were negative for alcohol but showed elevated levels of carboxyhemoglobin, cyanide, nicotine, and cotinine, likely from heavy cigarette smoking.
The NTSB chief medical officer reviewed the pilot's autopsy, toxicology, medical records, and FAA file. The autopsy revealed several heart abnormalities, including an enlarged heart (470 grams), severe calcifying atherosclerosis of all three coronary arteries with greater than 90% occlusion of the left anterior descending artery and 99% occlusion of the right coronary artery, and a severely calcified and stenotic aortic valve.
Review of the pilot's FAA medical records showed that in 1995 he reported a transient loss of vision in his left eye in June 1994, attributed to a cholesterol embolus lodged in a small retinal arteriole. Subsequent tests were negative, but a follow-up exam revealed an additional cholesterol plaque. In 2002, the pilot was diagnosed with glaucoma and received a special issuance certificate requiring annual ophthalmologic evaluations, which he performed routinely. At the time of the accident, he held a valid second-class medical certificate with the limitation that he wear corrective lenses.
Search and Rescue
When the helicopter failed to arrive in Iliamna, company personnel initiated telephone and satellite phone searches. Unable to locate the helicopter, they contacted the Air Force Rescue Coordination Center in Anchorage. Rescue personnel aboard an Air National Guard C-130, aided by flares, searched throughout the night but did not find the helicopter or detect an ELT signal. The wreckage was discovered the next morning by a company Bell 212 crew.
Engine Examination
On February 8, 2012, the engine was disassembled and examined at Turbomeca USA. The examination revealed circumferential scoring marks on internal rotating components consistent with power production at impact. There was deformation to first stage compressor blades and contact signatures on compressor axial stages, impellers, and shrouds. No evidence of preimpact mechanical anomalies was found.