An undetermined problem in the cockpit forced a Shanghai-bound Air Canada flight to land at YVR airport Saturday morning shortly after takeoff, officials say.
Air Canada spokeswoman Angela Mah said flight AC25, which departed at 11:05 a.m., had just reached 14,000 feet when the captain noticed a troubling sound.
"The captain detected a whistling noise from the window in the flight deck so he immediately returned to YVR," she said.
Mah said the incident was uncommon, but described the landing as "normal, routine and safe."
Maintenance crews are inspecting the aircraft, a Boeing 767 jet, to determine the nature of the sound.
The flights 166 passengers and nine crew members are being transferred to another 767, which is expected to take off at around 3 p.m.
"We have to transfer the passengers, the catering and the luggage over," Mah said.
It is expected to land in Shanghai roughly four hours after its scheduled arrival.
