What happened
On a mission for Environment Canada, a Bell 2COB helicopter, registration C-GCQT, was conducting water sampling operations across several lakes north of the Vancouver lower mainland. After completing landings at eight different locations under light winds, the crew attempted to land on Devils Lake. At the time of the approach, the water surface was completely calm and shaded by surrounding hills, creating a mirror-like effect.
As the pilot executed a shallow approach from the south, the aircraft struck the water surface earlier than anticipated. The impact caused the floats to dig into the lake, resulting in the helicopter flipping onto its back. While the inflatable floats kept the airframe buoyant, the cabin became submerged. The pilot and one passenger successfully exited the wreckage, but a second passenger was initially trapped and unconscious. Although the passenger was rescued from the submerged cabin, she succumbed to her injuries six days later. The accident resulted in one fatality.
The investigation
Investigators examined the wreckage and flight records of the Bell 206B. The aircraft had recently undergone an overhaul and was functioning normally, though it lacked a radar altimeter. Weight and balance calculations confirmed the aircraft was within safe operating limits at the time of the accident.
Physical examination of the wreckage showed that the main transmission had been dislodged from the airframe and the engine drive was disconnected. During the impact, one main rotor blade struck the water at high speed and broke; the broken blade then penetrated the cockpit area. The investigation also noted that the pilot was wearing a flight helmet, which prevented serious head trauma, while the passengers were not wearing helmets.
Findings
- Glassy water conditions prevented the pilot from accurately judging the aircraft's altitude above the lake surface.
- The helicopter's floats caught the water upon contact, causing the aircraft to capsize.
- The breakage of a main rotor blade upon water impact led to debris striking the occupants' heads.
- The survival of the pilot and the successful rescue of the unconscious passenger were aided by the passenger's recent underwater emergency escape training and the availability of a satellite telephone for emergency communication.