NEW YORK (MarketWatch) -- Air France flight 447 may have stalled at 35,000 feet as it was slowing down to enter a turbulent storm over the Atlantic, leading to its crash. According to a Paris-based Le Monde story on Thursday, Airbus is preparing new advice for operators of its A330 on flying into storms, warning them to maintain adequate thrust when entering heavy turbulence. Aircraft typically slow down as they enter storms to minimize turbulence. The Airbus warning suggests that the A330 flown by Air France and crashed, killing all aboard, may have slowed too much for a storm it was approaching and stalled. A stall at 35,000 feet would be difficult to recover from for a large, wide-body aircraft, according to media reports.