Bangladesh, Oct. 6 -- A British Airways Boeing 777 bound for Chicago returned to London Heathrow Airport on October 5 after a reported loss of cabin pressure forced the crew to carry out an emergency descent over the Irish Sea.

Flight BA295, a 777-200ER registered G-VIIA, was cruising at 36,000 feet about 40 nautical miles south of Dublin when the pilots began descending.

Passenger oxygen masks deployed, and the aircraft leveled off at 9,000 feet roughly seven minutes later, after descending 27,000 feet at an average rate of about 3,800 feet per minute.

The crew transmitted the emergency transponder code 7700 before turning back toward London. Flight-tracking data showed the aircraft circling near southwestern Britain for an extended ...