downed helicopter

This photo provided by the Alaska Mountain Rescue Group shows an Alaska Army National Guard helicopter at the scene of a helicopter crash near Knik Glacier in Alaska on Sunday. Federal investigators say a helicopter carrying five passengers on a heli-skiing trip in Alaska crashed into a mountain and then rolled downhill nearly 900 feet. The pilot and four of the five passengers on board died in the crash The National Transportation Safety Board is investigating the cause of the crash just north of Anchorage on Saturday night. (Lance Flint/Alaska Mountain Rescue Group via AP)

The fatal crash on Saturday of a tour helicopter near Knik Glacier — in the rugged mountainous region northeast of Anchorage, Alaska — raises numerous safety questions about the helicopter tour operator at the center of the incident, according to a news release issued Monday by an Austin, Texas-based law firm.

“Five people on board the Airbus AS350 B3 helicopter died when the aircraft crashed while conducting a heli-skiing flight. One person survived and is hospitalized. The National Transportation Safety Board is investigating the incident and has not yet released a cause at this time,” the release says.

Aspenite Greg Harms was among those who died in the crash. “Prominent Czech billionaire businessman Petr Kellner was one of the five people killed in Saturday’s crash,” the release continues.

The aircraft was owned and operated by Soloy Helicopters of Wasilla, Alaska, which performs precision long-line and remote area operations, including heli-skiing.

“The aircraft condition, service record, modifications and suitability for the assigned mission need to be examined closely,” said Ladd Sanger, an aviation attorney with Slack Davis Sanger in Austin, Texas, and licensed helicopter pilot.

The helicopter was ferrying passengers from the Tordrillo Mountain Lodge, in Judd Lake, Alaska, to the mountains in the region near the glacier for remote skiing. Reports showed that the crash site was located in steep, snow-covered terrain.

Sanger said that the NTSB investigation will examine the weather conditions, as well as the training, experience, judgment and previous record of the Soloy Helicopters pilot. Also, the instructions, rules and discretion the company’s management followed and communicated to the pilot will be weighed.

“In the best of conditions, helicopter tour operations in remote mountainous areas like Alaska can be risky, and the high probability of sudden changes in weather or visibility poses an increased danger,” Sanger said. “Our firm has handled several Alaska helicopter crashes that occurred because the clouds and white snow-covered mountains caused the pilot to lose visual horizon reference, resulting in spatial disorientation. The results can be deadly.”

The AS350 B3 is a high-performance, single-engine helicopter typically operated by a single pilot. The aircraft has seating capacity for up to six, including the pilot.

Otherwise known in North America as the AStar, the AS350 is a heritage design of Aerospatiale, a French helicopter manufacturer that later became Eurocopter and, in 2013, was moved under the Airbus umbrella. Various versions of the AS350 have been produced in both France and in Airbus plants in the U.S.

Some AS350 helicopters have been modified with an engine-inlet barrier filter modification developed by a Soloy company based in Oregon, which has been implicated in previous AS350 accidents; however, no such modification had been made on the helicopter involved in Saturday' crash. Sanger represented the family of the flight nurse who was killed in a 2013 Airbus AS350 crash in Oklahoma City.

The NTSB determined the cause of that crash in 2013 to be ice trapped in the air inlet of a Soloy-modified filter, which was ingested during the flight, causing the engine to fail. The barrier filter system allows water to pass through the filter then freeze inside the filter. The frozen ice can then be ingested into the engine, causing it to flame out. 

To determine the circumstances and likely cause of the crash, NTSB investigators will examine the crash site and wreckage, flight records of the aircraft and pilot, and weather conditions at the time of the accident. Data and voice recorders have become widely available for even smaller helicopters over the last decade but are not required to be installed on older versions.