Richmond Hill, Ontario, 28 March 2024 — Today, the Transportation Safety Board of Canada (TSB) released its investigation report (A23O0108) into the 20 August 2023 fatal accident of a ground crew member during external loading operations involving an AS350 BA helicopter, near Wawa, Ontario.
The TSB conducted a limited-scope, class 4 investigation into this occurrence to advance transportation safety through greater awareness of potential safety issues. See the Policy on Occurrence Classification for more information.
The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.
Air transportation safety investigation report A23O0108
Ground personnel entanglement with external load
G4 Drilling Canada Ltd.
and
Expedition Helicopters Inc.
Airbus Helicopters AS350 BA, C-FHAU
Wawa, Ontario, 25 NM W
20 August 2023
History of the flight
On 20 August 2023, the Expedition Helicopters Inc. Airbus Helicopters AS350 BA helicopter (registration C-FHAU, serial number 2778) was conducting external load operations, moving drilling equipment, in support of Angus Gold Inc. mining exploration activities being conducted by G4 Drilling Canada Ltd. (G4) approximately 25 nautical miles (NM) west of Wawa, Ontario. The pilot was alone on board and occupied the right seat. The single-engine helicopter was equipped and configured to conduct external load operations—the pilot door was removed, a vertical reference window was installed, and a 100-foot longline was being used. There were no overdue maintenance items or reported defects before the occurrence. The weather was suitable for the day visual flight rules flight. The winds at Wawa were reported as being from the north at 10 knots, variable from 320° to 050° true.
The pilot’s task consisted of transferring surface drilling equipment by longline from an old drill site on an island to a new drill site on a nearby peninsula, approximately 900 feet away (Figure 1). The G4 ground crew consisted of a foreman, an assistant foreman, a driller, and a helper.
The pilot started his duty day at approximately 0615 and flew various short flights for about 2.5 hours. He was then off duty until the first drilling equipment transfer flight, which started at approximately 1520.
The foreman and the assistant foreman were stationed at the old site, preparing and attaching the drilling equipment to the longline, while the driller and helper were at the new site receiving, positioning, and detaching the drilling equipment from the longline. By approximately 1630, only the drill shack cage remained to be moved (Figure 2). This cage was to be placed over the drill and equipment on the drilling platform at the new site.
When the cage is carried by longline, the pilot cannot control the rotation of the cage during the transfer or during the descent into position, so the ground crew uses tag lines (Figure 2, inset) to help guide and position the cage down onto the platform.
When the helicopter reached the new site with the cage, the pilot, the driller, and the helper had difficulties positioning the cage. After several unsuccessful attempts, the pilot decided to bring the assistant foreman to the new site to help. The pilot flew back to the old site, released the cage, picked up the assistant foreman and took him to the new site. The pilot then returned to the old site, the cage was reattached to the helicopter, and the pilot flew back to the new site with the cage.
At approximately 1700, the pilot positioned the helicopter into the wind and lowered the cage over the drill. The driller and helper each held 1 tag line and the assistant foreman held 2 tag lines (Figures 3 and 4). 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.
After some time still being unsuccessful in positioning the cage, the pilot transmitted over the radio to the driller, who was the only one who had a portable handheld radio, that he had to go refuel the helicopter. This radio communication went unheard by the driller. The investigation could not determine why it went unheard.
The pilot began to climb and lifted the cage slowly while paying attention to the cage and any hand signals from the ground crew. As he continued to lift the cage, he did not see any hand signals from the driller or helper, and assumed that he was clear and continued to lift. As the cage lifted, the assistant foreman became entangled in his 2 tag lines. The driller and helper were concentrating on their own tag lines and did not see the assistant foreman become entangled. As the helicopter climbed and departed, the assistant foreman was carried 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. 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 pilot departed the area and climbed to approximately 200 to 300 feet above ground level over the nearby lake.
A few moments later, the driller and helper saw the assistant foreman fall. At 1722, the driller texted the project lead at the base camp to report the accident.
The pilot was still unaware of the accident but, hearing the tone in the driller’s voice over the radio, felt that something had gone wrong. He proceeded to the old site, dropped off the cage and asked the foreman to accompany him back to the new site. After landing at the new site, the pilot and foreman were made aware of the accident. The pilot returned to the base camp, refuelled, and returned with 2 passengers to search for the assistant foreman. He was found on land, in a forested area across the lake from the new site, and had been fatally injured.