Delta DL251 Diverts to Porto After Smoke Fills Cabin

A Boston-bound Delta A330 declared an emergency over the Atlantic and landed in Porto, with four people hospitalized after smoke filled the cabin.

Delta flight DL251, an Airbus A330 flying from Barcelona to Boston Logan, diverted to Porto, Portugal, on Sunday, September 27, after smoke was reported in the cabin. The aircraft departed Barcelona in the mid-afternoon, was roughly two and a half hours into its eight-and-a-half-hour flight, and had already crossed toward the Atlantic when the crew turned the wide-body around. It landed safely at Francisco Sá Carneiro Airport around 6 p.m. local time, where firefighters, police, and ambulances were waiting. The aircraft was carrying 296 people, according to the New York Post and Sur in English.

A transatlantic flight aborting mid-ocean is rare enough, but this one had already left the Spanish mainland and was over open ocean when the crew declared a general emergency with a Squawk 7700 transmission and requested the nearest suitable airport, according to airlive. Passengers told outlets that smoke suddenly began rising in the cabin, triggering emergency procedures while the jet cruised near 32,000 feet. The New York Post notes it was the second smoke-related Delta diversion in recent weeks, after an August 13 Atlanta return prompted by a smoky smell.

Flight-tracking data cited by the New York Post shows the jet peaked near 32,000 feet and made a sharp diversion some 500 miles off the Portuguese coastline. airlive reports the aircraft was an 11-year-old Airbus A330-300, registration N824NW, which landed safely on Porto's runway 35. Portuguese daily Correio da Manhã reported 14 people were assisted by medical staff and four were taken to hospital, per Sur in English. Sur in English adds that São João Hospital in Porto confirmed two male passengers were admitted with mild, stable respiratory symptoms from smoke inhalation.

Reports differ on the exact number hospitalized: the Economic Times, airlive, and Sur in English say four, while Yahoo/People reports three, so the count remains subject to confirmation. What is consistent across outlets is that 12 people needed oxygen mid-air, per Portuguese press cited by airlive, Sur in English, and the New York Post, and eight were treated on the tarmac, per Yahoo/People. The cause has not been determined, and authorities and the airline have opened an investigation, according to the Sportschosun report citing the Daily Mail.

The diversion left the aircraft and crew out of position, forcing Delta to cancel connected flights DL276 and DL277, airlive reports. Affected passengers were rebooked on alternative routes or given accommodations. The New York Post says the Monday 1 p.m. continuation from Porto was canceled, with Delta instead operating a Boston-bound flight from Barcelona at 3:15 p.m. Monday. The Economic Times reports the remaining 282 passengers were safely evacuated.

Delta confirmed to Reuters that flight DL251 was diverted following a report of a mechanical issue, apologized for the delay, and has not shared what caused the smoke, according to Yahoo/People. Portuguese authorities and the airline are investigating, and the incident follows a pattern of cabin-smoke events the outlets have tracked, including an Alaska Airlines flight to Honolulu on September 24 where seven Hawaiian Airlines flight attendants were evaluated after an unknown odor made people ill. Travelers on affected routes should watch for schedule changes as the A330 remains out of service.