It is everyone's worst nightmare to be stuck on a plane while looking over at an engine in flames, and that is exactly what happened during a British Airways flight today.
The flight had to make an emergency landing at Heathrow today after it set off for Oslo.
The Airbus A319 had 75 passengers on it, but managed to safely land after a "technical fault" with the engine.
Indeed, there was a technical fault, as passengers noted that they saw smoke and flames billowing from one of the plane's engines.
Some believe the plane had run into a bird and this is what caused the fire, but there is no confimation about its cause yet.
A spokesman for the airport said all passengers "safely evacuated" and are "accounted for."
The airport will remain open throughout the day and remained open during the incident, though they had to close both runways for some time.
They have ruled out a terror attack as a cause and investigators are now looking into whether or not a bird had anything to do with it.
David Gallagher, a passenger on the flight, recalls the startling sounds of the engine shutting down.
"About eight or nine minutes into the flight there was a loud popping sound, not an explosion but definitely not usual sounds," he said. "There was some concern from passengers - people gasping and louder exclamations. The captain came on very calmly, said he was aware of the situation and everything was running normally and he was going to run some tests to see what the right course would be."
"Then, another five minutes after that there was a loud sounds, and this time the right engine was clearly on fire. I mean, big flames, very visible from the rest of the cabin with lots of black smoke."
Despite losing that engine, Gallagher noted that there was not any disturbance to the actual flight and it was flying smoothly.
"There was no disruption to the flight at all, even when it was clear we were down to one engine."
Those on the right side of the plane, understandably, were more upset as they could see that something was seriously wrong.
"A few passengers were upset understandably, especially those on the right side of the plane. The cabin crew and ground crew were outstanding and completely calm, reassuring and professional during the whole incident," Gallagher said.
Photos taken from inside the plane showed that an inspection cover came loose on the engine.
David Learmount, operations and safety editor of Flight Global publication, said the cover was damaged, possibly because of a bird strike.
"This cover is to a plane what a bonnet is to a car. It should not have been open. Something caused it to be dislodged," Learmount said.
"Pictures of the plane flying with smoke coming from it indicate that the aircraft was being powered entirely by the left-hand engine. Most likely there was external damage to both engine."