[A U.S. Delta Airlines flight made an emergency landing and smoke appeared in the cabin] On September 28th, U.S. Delta Airlines said that one of its Airbus A330 passenger planes made an emergency landing in Portugal on the afternoon of the 27th after smoke appeared in the cabin during the flight. The flight, numbered DL251, was originally scheduled to fly from Barcelona, ​​Spain to Boston, the United States. There were 296 passengers on board. The 24-hour flight radar website showed that the flight took off from Barcelona at 15:15 local time on the 27th and landed at Francisco Sa Canero Airport in Porto, Portugal at 17:45 local time. A spokesman for the Portuguese Emergency Rescue and Civil Protection Department said that eight passengers were treated at the airport and several others were sent to the hospital. The reason for the emergency landing was the presence of smoke in the cabin. It's unclear what caused the smoke.