Air Canada flight sparks emergency scare after mid-air U-turn back to Heathrow

An Air Canada flight declared a mid-air emergency shortly after taking off from London Heathrow Airport. Flight AC853, heading for Toronto, departed the London airport at 8:34cm on Saturday, climbing to 34,000 feet and heading out over the Atlantic as normal. But less than an hour into the journey, the crew declared an emergency, transmitting a Squawk 7700 code, which alerts air traffic control to a serious issue on board. The aircraft, a Boeing 777-300ER, quickly a bandoned its transatlantic route and made a controlled turnaround back towards Heathrow, with emergency services placed on standby as a precaution. The nature of the emergency has not yet been confirmed by Air Canada, with such alerts used for a range of situations including technical faults or medical incidents. Tracking data shows the aircraft began its return shortly after reaching cruising altitude at around 09:15 BST, before descending back towards London. The plane safely touched down on runway 27L at approximately 10:02 BST, with landings briefly suspended on Heathrow’s south runway moments later. Passengers onboard were brought back to the terminal after the aircraft taxied to the gate under escort from emergency vehicles. Despite the dramatic turnaround, there have been no reports of injuries. Air Canada has since moved to reschedule the disrupted service, with a replacement departure planned for later in the morning. Heathrow emergency crews remained on standby throughout the incident, following standard protocol for any aircraft declaring a full emergency. The incident is now expected to be reviewed, with further details anticipated from the airline and airport authorities.