CALGARY — An Air Canada flight bound for Toronto was forced to interrupt its journey and declare an emergency shortly after departure, returning to Calgary International Airport (YYC).
Air Canada Flight AC138, operated by an Airbus A321 registered as C-GITY, departed Calgary at 10:40 a.m. local time—approximately one hour behind its scheduled departure. The flight was en route to Toronto Pearson International Airport (YYZ).
During the initial ascent, as the aircraft climbed through roughly 30,500 feet, the flight crew halted the climb, turned back toward Calgary, and squawked code 7700, the international transponder code used to signal a general emergency to air traffic control.
Flight tracking data showed the aircraft descending and holding at 10,000 feet as it made its approach back toward Calgary International Airport. Maintaining an altitude of 10,000 feet is standard procedure for flight crews experiencing cabin pressurization issues, as standard atmospheric pressure at that level allows passengers and crew to breathe comfortably without supplemental oxygen.
Emergency ground crews and airport response units were alerted at YYC to prepare for the aircraft’s return. Further details regarding passengers onboard or specific mechanical conditions have not yet been confirmed by Air Canada or transport safety officials.
This is a developing story.
UPDATE 17:56 UTC
Touch down. The aircraft is met by fire trucks.
UPDATE 18:10 UTC
The airline is scheduling a new departure at 13:00 local time.




