LONDON - Managers at Heathrow Airport boasted last month that their snow team was working flat out to ensure the facility "will once again be prepared for the onset of winter."

Then a few inches of snow fell, and Europe's busiest airport shut down. People slept on floors under foil blankets, or were turned away outside terminals, Christmas travel plans in ruins.

Flights were returning to normal Wednesday, but the fallout continued, with Heathrow boss Colin Matthews renouncing his annual bonus as a gesture of contrition.

With passengers still deeply angry and politicians echoing their complaints, the most enduring damage from the snowstorm may be to the reputation of an airport that was already overcrowded, unloved, and in need of an upgrade.

Wolfgang Prock-Schauer, chief executive officer of airline BMI, put the blame squarely on Heathrow's owner, Spanish-owned company BAA.

"BAA was not prepared," Prock-Schauer told the Times newspaper. "It did not have enough deicing fluid."

Heathrow said the chaos was a result of the airport's lack of spare capacity and unusually harsh weather - Meteorological Office figures show 31/2 inches of snow fell Saturday and quickly froze. The airport, which said 5 inches fell, strongly denied running short on deicing fluid.

On Wednesday, Heathrow said it was running almost 900 flights, 70 percent of a full service, after finally reopening both runways for the first time since Saturday. Many of the travelers who had slept on terminal floors amid mounds of luggage were finally getting on planes. But they were not happy.

David Sorrell, trying to get to Australia with his wife and two children, said conditions this week were "atrocious - people sleeping on the floor, people drunk, we had people shouting and screaming, people wanting to have fights. It's like a refugee camp."

BAA would not reveal the size of the bonus Matthews is giving up, but his salary and bonuses for last year came to 944,000 pounds ($1.46 million).

He said the airport was "fully operational" but acknowledged "it's still going to take several days to get everyone where they want to be."

He said that Heathrow would buy new cold-weather equipment, and he promised this week's chaotic scenes would not be repeated.

"Now that the runways are fully operational, we can turn our attention to making sure it never happens again," he told Sky News. "Events proved we weren't adequately prepared."

BAA, which owns Heathrow and five other British airports, was formed in 1986 when the state-run British Airports Authority was privatized.