A British Airways flight from London to Chicago declared an emergency over Ireland on Monday after making a rapid descent of nearly 28,000 feet, data from flight-tracking website flightrader24 showed.
British Airways flight BA295, operating from London Heathrow to Chicago O'Hare, had climbed to about 37,000 feet before descending sharply to around 9,000 feet while flying over Ireland. The Boeing 777-200ER, registered as G-VIIA, had departed Heathrow's Terminal 5 at about 11.50 a.m. local time.
The aircraft reportedly transmitted the 7700 emergency transponder code, an internationally recognised signal indicating that a flight is facing a general emergency and may require priority assistance from air traffic controllers.
Flight-tracking data later indicated that the aircraft had turned back towards London Heathrow, suggesting that the scheduled transatlantic service to Chicago had been abandoned.
The reason for the emergency was not immediately known. The aircraft was about an hour into its journey when it began the steep descent. There was no immediate information on whether the incident involved a technical problem, a medical emergency or another operational issue.
British Airways had not immediately provided details about the incident or confirmed the reason for the aircraft's return.