A British Airways flight, BA295, was on its way to the United States when it had to abandon its journey due to an unspecified emergency on Monday. The flight lost thousands of miles in altitude within minutes over Ireland.
The plane, Boeing 777-200ER, was travelling from London’s Heathrow Airport to Chicago O’Hare when something went wrong after an hour into the journey.
The flight was at around 37,000 feet high before beginning a quick descent over Ireland, flight-tracking data reveals. It descended around 28,000 feet before leveling off at 9,000 feet.
During the incident, the pilots also began “squawking 7700,” an international emergency code that immediately tells air traffic controllers that an aircraft requires priority assistance.
The flight then turned around instead of continuing across the Atlantic and headed back towards London Heathrow.
What went wrong?
That remains the biggest unanswered question. The 7700 code confirms that the crew considered the situation serious enough to declare a general emergency, but it does not reveal what caused it.
Pilots can use the code for several situations, ranging from a technical problem to a medical emergency or another issue requiring immediate assistance from air traffic control.
However, one part of BA295’s flight path stands out.
Dropping from 37,000 feet to around 9,000 feet would be consistent with the kind of emergency descent pilots may carry out following a cabin pressurisation problem.
At cruising altitude, passengers cannot safely breathe for long without supplemental oxygen if normal cabin pressure is lost. Getting the aircraft down to a much lower altitude therefore becomes a priority.
But there is an important distinction: there is currently no confirmation that BA295 suffered a loss of cabin pressure.
Flight-tracking websites can show where an aircraft flew, how high it was and whether its transponder was broadcasting an emergency code. They cannot show what was happening inside the cockpit or cabin.
British Airways had not publicly identified the specific problem at the time of reporting.
BA295 was being operated by G-VIIA, a Boeing 777-200ER that is around 30 years old; however, the age of the aircraft alone does not establish what caused Monday’s emergency.
