Lack of visual cues brought down Coast Guard helicopter
December 7, 2015 By Transport Canada
In its investigation report (A13H0002) released today, the Transportation Safety Board of Canada (TSB) determined that a strong probability of a lack of visual cues to judge altitude led to the fatal September 2013 crash of a Canadian Coast Guard (CCG) Messerschmitt-Bölkow-Blohm BO 105 helicopter in the M’Clure Strait, Northwest Territories.
On September 9, 2013, at 16:38 Mountain Daylight Time, the helicopter took off from the CCG vessel Amundsen for a combined ice measurement and reconnaissance mission in the M’Clure Strait, with the pilot, ship’s master and a scientist aboard. At 17:38, the helicopter informed the Amundsen that it would return to the vessel in 10 minutes; however the helicopter did not arrive at its intended time. At 18:05, the helicopter’s position was checked on the flight following system, which displayed it as being 3.2 nautical miles from the vessel. At 18:18, the Amundsen’s crew attempted several times to communicate with the helicopter without success and soon after proceeded to the helicopter’s last position. Debris was spotted and the three occupants were recovered. None survived. The helicopter sank in 458 metres of water and was recovered 16 days later.
The investigation found that there was a strong probability that a lack of visual cues to judge altitude while flying low over open water, combined with the possibility of pilot distraction, resulted in the loss of altitude and the collision with the water. The three occupants likely drowned due to cold incapacitation, as none of them were supported in a way to keep their airways above the water line. Further, the 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 flight following system also did not provide an aural warning to alert the vessel’s crew immediately that the helicopter was no longer transmitting position reports. The investigation also found numerous factors as to risk, including deficiencies related to the proper usage and wearing of survival suits by flight crews, packing of personal flotation devices, egress training, and operational and regulatory oversight.
The helicopter was not equipped with a flight data recorder or cockpit voice recorder, nor was it required to by regulations. Had the aircraft been equipped with these systems, investigators would have been able to better understand the circumstances and events that led to the accident. The Board has an outstanding recommendation (A13-01) for the implementation of flight data monitoring and the installation of lightweight flight recording systems by commercial air operators not currently required to carry these systems. The current Board assessment is Satisfactory Intent.
Following the occurrence, Transport Canada Aircraft Services Directorate introduced additional risk management measures for low-level helicopter flights and shipboard operations. New survival equipment including survival suits and personal flotation devices were also introduced. Additionally, a new fleet of helicopters to replace the BO 105 was acquired. The new fleet is equipped with automatic float deployment, externally mounted life rafts, cockpit voice recorders and flight data recorders, among other safety enhancements. For its part, the CCG 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.