Coast Guard helicopter crashed in Arctic due to lack of visual cues, pilot distraction

A fatal Coast Guard helicopter crash in the Arctic Ocean in 2013 was likely due toa lack of visual cues to judge altitude while flying low over open water, according to a report released today by the Transportation Safety Board.

Three people died, including the pilot, when the helicopter crashed Sept. 9, 2013 in theM'Clure Strait in the Northwest Territories.

The helicopter was travelling with the Canadian Coast Guard icebreakerAmundsen, which had recently departed Resolute, Nunavut, on a research voyage.At the time of the crash, the helicopter was on a reconnaissance mission on the state of the ice in the area.

The men who died were:

• Daniel Dub, helicopter pilot.
• MarcThibault, commanding officer of theCCGSAmundsen.
• Klaus Hochheim, an Arctic scientist affiliated with the University of Manitoba.

The helicopter was not equipped with a flight data recorder or cockpit voice recorder, nor was it required to be by regulations.

The report says thereis a strong probability that, while over the open water, the pilot lacked the visual cuesrequired to judge altitudeand it's possible adistraction could have caused a lapse in the pilot's concentration, resulting in a loss of altitude and contact with the water.

"The aircraft was initially flying over the ice, and it ended up flying over a pool of water. There's a lot of visual references that are needed to judge your height, and it can be anything that provides contrast,"saidJean-MarcLedoux, theTSB'sleadinvestigator in the case.

"The fact that he was over water that was calm, it's like a mirror and he ended up without having a depth perception, and it's really difficult to judge your altitude.We believe there's a strong probability that the pilot lost those visual cues that would have helped him to judge his altitude."

The weather was not a factor, Ledoux said, as shown by photographs and video recovered from the helicopter that were taken during the flight.

"We could see that visibility was not a problem;the ceiling the height of the cloudswas not a problem."

Ledouxsaid the aircraft's low altitudemeanta momentary distraction from inside or outside the cabin could have been enough to lead to the crash.

"Flying at 20 feet above the surface doesn't give you much time to react to any emergencies, anomalies or distractions," he said.

The TSB says the three men likely drowned due to cold incapacitation, as none of them were supported in a manner to keep their mouth and nose above the water line. The helicopter's liferaftsank with the aircraft. It is also possible they could have drowned while exiting the aircraft.

Regulations did not require either the pilot orthe passengers to wear immersion suits, though all three were. All three also had personal flotation devices.

The pilotwas not wearing hislife vest when his bodywas found, but it was found nearby, fully inflated.

Ledoux says there could be many reasons the pilot removed his life vest. He may have been trying to fully zip his survival suit to prevent heat loss, or he may have been intending to dive below the surface perhaps to help a passenger exit the helicopter or retrieve the helicopter's life raft.

The life vest on the Amundsen's captainwas not inflated, which Ledoux says could indicate he becameincapacitated by the cold water or drowned before he could activate the vest.

The third man'svest was only partially inflated, despite both cords having being pulled. Ledoux says tests done on the life vests have since shown that if they are rolled up instead of folded while being packed into their storage devices, and both cords are not pulled at the same time,they may not fully inflate.

The report also saysthe search and rescue operation from the Amundsen was delayed, as the vessel's crew was inadequately trained to use and interpret information from the flight following system.

The last communication from the helicopter was at 5:38 p.m. MT, saying it wason its way back to the ship and would arrive in 10 minutes. The Amundsen's crew attempted several times to communicate by radio with the pilotwithout success, then started towardthe helicopter's last position at 6:24 p.m.They spotted debrisat 6:47 p.m.

The helicopter sank in 458 metres of water and was recovered 16 days later.

It also says the Coast Guard has since revised and clarified instructions for the flight following system and introduced new policies requiring the use of dry-type immersion suits with appropriate thermal protection for helicopter operations in the Arctic.