The Transportation Safety Board of Canada (TSB) has released its final report on the events that led to a ground crew worker becoming entangled in a helicopter tag line and falling over 100 feet to his death in Wawa, Ontario, last year.
The report — which does not assign fault or determine liability — notes challenges in communication between the anglophone pilot “who did not understand French” and francophone ground crew “who spoke English with some difficulty,” as well as the limitations of radio communication when a head set or boom mic are used.
The accident took place on Aug. 20, 2023, as the aircraft — an Airbus AS350 BA operated by Expedition Helicopters — was completing drill equipment moves in northern Ontario in support of Angus Gold Inc. mining exploration activities.
The pilot was alone on board and the aircraft was configured for external load operations with the pilot door removed, a vertical reference window installed, and a 100-foot longline underneath.
The pilot was moving the equipment between two sites that were about 900 feet apart.
The ground crew included a foreman and an assistant foreman at the first site, and a driller and a helper at the second site. The two working at the first site prepared and attached the equipment to the longline, while the two at the second site received, positioned, and detached the equipment.
The move began around 3:20 p.m., and by about 4:30 p.m., only the drill shack cage (which is placed over the drill and equipment) remained to be moved.
After one unsuccessful attempt to place the cage at the second site, the assistant foreman joined the ground crew there to help. The driller and helper each held one tag line to guide and position the load, while the assistant foreman held two tag lines.
“When the pilot looked down through the vertical reference window, he could see the driller and the helper only, because a piece of plywood on top of the cage was blocking his view of the assistant foreman,” the report states.
The aircraft and crew continued to have problems positioning the cage, and eventually the pilot radioed the driller — the only one on the ground who had a portable radio — that he had to go and refuel. This went unheard by the driller.
The pilot began to climb and lifted the cage slowly. He said he did not see any hand signals from the driller or helper, and assumed he was clear and continued to lift.
As the cage lifted, the assistant foreman became entangled in his two tag lines. The two other ground crew were concentrating on their own tag lines and did not see the assistant foreman become entangled. The helicopter climbed and departed, carrying the assistant foreman aloft.
“When the driller and helper realized that the assistant foreman was being carried away, the driller called the pilot on the radio to inform him,” the report states. “However, the radio call was made in French, and given that the pilot did not understand French, he could not understand what was being said.”
The aircraft climbed to about 200 or 300 feet above ground level, and a few moments later, the driller and helper saw the assistant foreman fall. The driller texted the project lead at the base camp to report the fall.
While the pilot was unaware of the accident, “hearing the tone in the driller’s voice over the radio, [he] felt that something had gone wrong,” the reports states.
The pilot flew to the first site to pick up the foreman and returned to the second site. After landing there, they were told about the accident.
The pilot returned to base camp, refuelled, and returned with two passengers to search for the assistant foreman. They found him on land, but he had been fatally injured in the fall.
In its investigation, the TSB said the ground crew — who were all employees of G4 Drilling Canada — were required to have completed a core training program and on-site specialty training. However, this was only mandated to be completed within 12 months of a worker beginning their work.
While the foreman, driller and helper had all completed this training, the TSB said it found no documentation to indicate the assistant foreman — who had only been with G4 since July 12, 2023 — was qualified as a driller or had received any of the core or specialty training.
It also noted that it was “common practice” for G4’s ground crew members to put their hand in the closed weighted loop at the end of the tag line, or wrap it around their arms, wrists or hands.
Finally, it highlighted the issue of communication, noting how hand signals can eliminate the need to manually operate a radio, the clarity of which can be masked by the external noise of a helicopter hovering overhead.
“Signals can also be an effective way to communicate if the ground crew and pilot do not speak the same language, as was the case in this occurrence,” the report states.
Regardless of the method of communication, it should be pre-determined with the pilot before the lift and communicated to all involved during training and ground briefings, the TSB said.
It also noted a similar occurrence just two days before the accident that involved the same pilot and ground crew.
In that incident, the aircraft was lifting the drill shack cage after the assistant foreman had signalled to the pilot to do so, when the helper ran through the cage and became entangled in a rigging line.
He was lifted about four feet in the air before the assistant foreman signalled to the pilot to descend. The helper was lowered to the ground and was uninjured.
While the group discussed the incident among themselves, it was not reported to their respective companies.
The report ends with safety messages reminding pilots to ensure all ground crew members are clear of loads before lifting, and reminding ground crew members of the need for training and vigilance when working with external loads.
“Personnel who operate radios are reminded that communications need to be made clear by using language and terminology that can be understood by all parties involved, and these transmissions should be acknowledged to ensure that the message is understood,” the report states.
