Accident
On a routine resupply mission, a Canadian Coast Guard Bell 212 helicopter (registration C-GCHG, serial number 30625) departed Newtown, Newfoundland, on a visual flight rules flight to Cabot Island, a small island approximately six nautical miles offshore. The aircraft was delivering fresh water to the lighthouse keeper's residence, using four 40-gallon plastic barrels carried in a net slung 120 feet below the helicopter. After ground personnel on Cabot Island detached the full barrels and reattached a similar load of nearly empty barrels for the return flight, the helicopter departed. Shortly after departure, a worker on the island observed a splash in the water. Small pieces of aircraft wreckage and the netload of barrels were seen floating a short distance from the shore. The pilot, who was the sole occupant, was fatally injured in the crash.
Investigation
The Transportation Safety Board (TSB) investigation determined that the pilot was trained and experienced in slung-load operations and vertical-reference flying, and the operation had proceeded smoothly throughout the day. Weather conditions were suitable. No pre-existing mechanical discrepancies were found that could have led to the occurrence. A radio call made minutes before the accident indicated that the pilot believed the aircraft was functioning normally. The absence of a distress call and the fact that the slung load was not jettisoned before water contact suggest a sudden and severe event that gave the pilot no opportunity to react.
The investigation found that the circumstances—loss of the hook assembly toward the rear of the aircraft, disruption of flight controls around the hook assembly, mast bumping, and the suddenness of the accident—were consistent with the load contacting the water. The helicopter would have had to descend after departing the island to allow such contact, but no reason for the descent was established. The location of the main rotor within the debris field suggested that rotor/mast separation occurred at low altitude. Drag forces from load/water contact likely caused a sudden aircraft upset, leading to mast bumping and main-rotor separation. In-flight damage to flight controls from the hook assembly tearing away may have contributed to excessive flapping angles and prevented recovery.
The report also noted that the pilot did not wear the required shoulder harness or life jacket because they interfered with vertical-reference operations, a common practice among pilots. Immersion suits were not worn, and the pilot did not have ready access to the onboard life raft. The aircraft was not equipped with an underwater locator beacon, which delayed wreckage recovery.
Findings
The TSB identified the following findings as to causes and contributing factors: during departure from the island, the helicopter descended, for undetermined reasons, to an altitude that allowed the load to contact the water. Drag forces on the hook assembly during load/water contact resulted in loss of the hook assembly, disruption of flight controls, loss of aircraft control, and rotor/mast separation. Additional findings noted risks related to the non-use of safety harness and life jacket, lack of immersion suit requirements, and absence of an underwater locator beacon. The TSB issued safety advisories on these issues, and Transport Canada took subsequent actions including installing underwater beacons on Coast Guard helicopters and convening a working group on survival equipment criteria.
Probable Cause
During departure from the island, the helicopter descended, for undetermined reasons, to an altitude that allowed the load to contact the water. Drag forces on the hook assembly during load/water contact resulted in loss of the hook assembly, disruption of flight controls, loss of aircraft control, and rotor/mast separation.