Passengers flying to Valencia aboard a BA flight were terrified after the cabin of their Airbus A321 began filling with thick smoke.
Travellers on flight BA422 complained of difficulty breathing as the cabin smoked up on approach to land at Valencia airport.
"Still waiting to hear what actually happened," said passenger Gayle Fitzpatrick, who was flying with his wife from Heathrow.
"I think everyone is still in shock. No one knew what was happening," he said. "The most important thing is we are all safe. It was very surreal and scary."
Footage from those onboard shows the thick smoke obscuring vision so badly that it is difficult to make out the seat in front.
Passenger Michael J Galindo told LBC radio that he was travelling on the plane with his daughter. They eventually were evacuated on the runway at Valencia airport via inflatable emergency exit ramps.
In spite of the dramatic arrival and disembarkation, the flight arrived on time at Valencia
The airline released a statement following the incident, saying: "We can confirm that British Airways flight BA422 from Heathrow to Valencia has been involved in an incident today.
"The aircraft, an A321, has landed and all customers and crew have disembarked. British Airways teams are assisting customers who are in the airport terminal."
While the cause of the smoke was as yet unclear, all passengers and crew were evacuated safely in spite of passengers claiming there was "no oxygen" and "no communication."