Maj. Martell Thompson of the Joint Rescue Co-ordination Centre in Halifax said the chopper's main rotor struck a wire on the Sir William Alexander on Monday night.
The helicopter landed on Shaw Island, about 70 kilometres southwest of Halifax, at around 10:30 p.m., Thompson said Tuesday.
Blair Hodgman, a resident of the island, said the helicopter landed on the front lawn of a summer residence belonging to Scotiabank president Brian Porter, who wasn't home at the time.
Hodgman said she was preparing dinner when she noticed a number of aircraft circling overhead and assumed they were looking for a lost fishing boat.
She said after the chopper landed, firefighters carrying oxygen tanks and axes arrived looking for the helicopter while neighbours showed them the gate to the lawn where it landed.
"We don't usually have that excitement," she said. "It's kind of quiet around here."
The RCMP and paramedics also arrived and crews cut a lock to enter the property and check the aircraft, Hodgman said.
She said the pilot went to a neighbour's house and asked to use the telephone to call his supervisor because he didn't have a cellphone with him.
"They were kind of ... embarrassed," she said.
Nobody was injured. The military will investigate what caused the helicopter to clip the ship's antenna, Thompson said.