Sequence & Resolution
Event Date05/02/2026
Level
Incident
CategorySmoke Indication
Flight PhaseEn Route
Affected AltitudeFL250
Technical Issue Details
•An Air Canada Boeing 777-300ER (C-FITL) performing flight AC853 from London Heathrow to Toronto with 369 passengers and crew members on board was climbing en route at FL250 when the crew detected an acrid, electrical odor.
•The odor originated in the mid-galley area and quickly spread forward to the front galley, accompanied by a visible haze in the cabin.
Outcome / Handling
•The flight crew declared a general emergency (PAN-PAN) and requested an immediate return to London Heathrow.
•The aircraft completed a safe overweight landing on Heathrow's runway 27L approximately 1.5 hours after departure.
•Airport rescue and firefighting vehicles met the aircraft on landing as a precaution, and all passengers were safely deplaned.
Current Status
•Following a technical inspection, Air Canada engineers determined that the acrid odor was caused by a faulty cooling fan.
•The flight was cancelled, and passengers were successfully rebooked on alternative flights to Toronto.
Flight Information
Flight NumberAC853
Flight Duration90 minutes
Landing Runway27L (LHR)