The plane was about to taxi for takeoff at 5:30 a.m. from Halifax, Nova Scotia, bound for Toronto when a cat named Ripples escaped his carrier under its unidentified female owner's seat, the Canadian Broadcasting Corp. reported.
Passenger Kyle Warkentin told the broadcaster flight attendants announced a brief delay because of a missing cat.
"Then the engine turned off and the whole power on the plane turned off, and they said they were doing this to calm the cat," Warkentin said.
Airport spokesman Peter Spurway said the cat was spotted in the cockpit, cowering in a dense bundle of wires.
"The way the Air Canada folks described it to me is they had to disassemble part of the cockpit to get to the poor little cat, which was terrified, as you can imagine," he said.
The airline re-booked some passengers, while others waited and sympathized with the cat's owner, whom Warkentin said appeared as traumatized as the cat.
"She was shaking, the poor thing," he said.