John Nance, an international air safety analyst told ABC News, "The lack of any weather problems at Heathrow, the first probability that you look at is fuel starvation -- the plane ran out of gas. Second, why that might have happened. Can be a very complex issue, and then the crew could have been as surprised as everybody else."
Steve Archer, an aircraft engineer, told ABC News that he doubted the plane simply ran out of gas. "There are too many backup systems on the aircraft for the pilot to be unaware that he was running out of fuel," he said. Archer admitted, however, he's mystified as to why the plane would lose all power so quickly.
David Learmont of Flight International speculated that "a major technical error may have caused the crash." In an interview with the BBC, Learmont said it was very unlikely that this was due to pilot error. "BA pilots don't make mistakes like that."
Robert Cullemore at Aviation Economics, a London-based aviation consultancy, said the pilot's efforts to keep the plane aloft prevented a catastrophe.
"If it had landed 200 meters shorter than it did, it may have hit the perimeter fence and obviously some other buildings and the car park. Clearly, we would be dealing with fatalities and obvious damage," Cullemore said.
When the jetliner crash landed, a jet carrying British Prime Minister Gordon Brown and Virgin Chairman Richard Branson was about a half mile away waiting to take off.
Britain's Air Accidents Investigation Branch is investigating the crash and a spokesperson told ABC News, "these kinds of investigations take a few months".
The Associated Press contributed to this report