The company did not address a possible cause for what happened.
A passenger, John Birkhead, said he and his wife had just stood up to stretch when they heard the explosion.
“We were just stretching and talking, and suddenly there was an enormous bang, and the whole plane shook,” Mr. Birkhead, 59, who was returning home to California after a two-week vacation, said. “We were lucky we weren’t tossed to the ground.”
Sarah Eamigh, another passenger, said she had been dozing when she felt her stomach plunge as the plane momentarily dropped, then lurched back up.
Ms. Eamigh, 37, who was returning from a business trip, described the sensation that followed as a pervasive humming feeling, entirely unlike the side-to-side motion of turbulence.
“Of course, we were all anxious,” she said. “We had a quick drop, and that obviously made someone yell, and we were white-knuckling our chairs.” The cabin remained relatively calm, she said.
About 20 minutes after the disturbance, the captain, whom Ms. Eamigh described as sounding shaken, announced that an engine had exploded.
Several hours after landing at Goose Bay Airport, passengers were just getting off the plane.
Mr. Birkhead said he had heard the reason for the delay was that the small airport — which is home to three air carriers, a coffee shop, a gift shop and three car rental agencies — was not prepared to accommodate the number of passengers on a jet the size of an A380. (Even the world’s biggest airport, in Atlanta, has had trouble accommodating planes of that model.)
“Nobody’s told us why, but the speculation is they’ve got nowhere to put 500-plus people — that’s probably the whole population of Goose Bay,” he said in an interview.
Air France said it was working to reroute passengers through one of its connecting sites in North America.
Ms. Eamigh said she was content, for the time being, on the tarmac.
“You make friends in a situation like this,” she said.
She added, with a laugh: “It looks pretty cold outside, so we’re actually O.K. here.”