The Air France flight that skidded into a ravine in Toronto this week appeared to land halfway down the runway before plunging off the end, investigators said Friday.

Real Levasseur, chief investigator for the Transportation Safety Board of Canada, said his team has interviewed witnesses at the airport who said they saw Flight 358 "land long" on Runway 24L in stormy weather. Fire erupted aboard the plane as it came to a stop off the runway Tuesday afternoon. All 309 passengers and crew escaped safely.

The witnesses' accounts could not be confirmed by radar or other information from the plane's flight data recorder because it had not been examined, Levasseur said. "It landed longer than normal for this aircraft," Levasseur told reporters Friday. He added that the probe was looking into how far along the runway the plane had touched down. The cockpit's voice and flight data recorders were sent to France so their data could be downloaded and are expected to return over the weekend.

If the witnesses' accounts are confirmed, the location of the plane's touchdown could become a major factor in the investigation into how the Airbus 340-300 barreled off the runway at 90 miles per hour near a major highway.

If the plane touched down midway, it would have had only 4,500 feet of pavement left to stop, a distance that some pilots said should provide enough room under normal weather conditions but not a length that they would prefer.

"The defined touchdown zone is the first 3,000 feet of the runway," said John Cox, safety consultant and former head of safety at the Air Line Pilots Association. Cox and other aviation experts said the ideal touchdown spot varies with each aircraft and depends on many factors, such as the wind and other weather conditions, runway conditions, the weight of the aircraft and its landing speed.

"You can't say this plane stops at X number of feet," said Clay McConnell, spokesman for Airbus North America. "It depends on a lot of factors."

Levasseur said skid marks from Flight 358 stretched 1,600 feet to the end of the runway. But he said it was unclear where the marks began because of other planes' tire marks.

The Air France plane's copilot, whose name was not released because of Canadian investigation rules, was at the controls when the plane landed and has been interviewed by investigators. Air France said the copilot, 43, joined the airline in 1985 and has logged 10,700 flight hours, including 2,500 on the A340. The captain, 57, was hurt in the accident and remained in a Toronto hospital with a back injury. He joined the carrier in 1982 and has logged more than 15,000 flight hours, including 1,000 hours on the A340.