A commuter jet mistakenly trying to take off on a runway that was too short crashed into a field and burst into flames, killing 49 people and leaving the lone survivor - a co-pilot - in critical condition, federal investigators said. Preliminary flight data from Comair Flight 5191's black box recorders and the damage at the scene indicate the plane, a CRJ-100 regional jet, took off from the shortest runway Sunday at Lexington's Blue Grass Airport, National Transportation Safety Board member Debbie Hersman said. The 3,500-foot-long (1,050-meter-long) strip, with less lighting and barely half the length of the airport's main runway, is intended for only daylight takeoffs and not for commercial flights. The twin-engine CRJ-100 would have needed 5,000 feet (1,500 meters) to fully get off the ground, aviation experts said. It wasn't immediately clear how the plane ended up on the shorter runway in the predawn darkness. There was a light rain Sunday, and the strip veers off at a V from the main runway, which had just been repaved last week. "We will be looking into performance data, we will be looking at the weight of the aircraft, we will be looking at speeds, we will pull all that information off," Hersman said. The Atlanta-bound plane plowed through a perimeter fence and crashed in a field less than mile (about a kilometer) from the end of that runway at about 6:07 a.m. Aerial images of the crash site in the rolling hills of Kentucky's horse country showed trees damaged at the end of the short runway and the nose of the plane almost parallel to the small strip. When rescuers reached it, the plane was largely intact but in flames. A police officer burned his arms dragging the only survivor from the cracked cockpit. The flames kept rescuers from reaching anyone else aboard - a newlywed couple starting their honeymoon, a Florida man who had caught an early flight home to be with his children and a University of Kentucky official among them. "They were taking off, so I'm sure they had a lot of fuel on board," Fayette County Coroner Gary Ginn said. "Most of the injuries are going to be due to fire-related deaths." FAA spokeswoman Laura Brown said the agency had no indication that terrorism was involved in any way in what was the country's worst domestic plane crash in five years. It's rare for a plane to get on the wrong runway, but "sometimes with the intersecting runways, pilots go down the wrong one," said Saint Louis University aerospace professor emeritus Paul Czysz. The worst such crash came on Oct. 31, 2000, when a Los Angeles-bound Singapore Airlines jumbo jet mistakenly went down a runway at Taiwan's Chiang Kai-Shek International Airport that had been closed for repairs because of a recent typhoon. The resulting collision with construction equipment killed 83 people on board. Comair President Don Bornhorst said maintenance for the plane that crashed Sunday was up to date and its three-member flight crew was experienced and had been flying that airplane for some time. The only survivor of the crash was identified as first officer James M. Polehinke, 44, who was in critical condition after surgery at the University of Kentucky hospital. "He's very lucky," said Dr. Andrew C. Bernard, a trauma surgeon. All 49 bodies had been recovered from the wreckage, said Stacy Floden, spokeswoman for the state Justice and Public Safety Cabinet. No positive identifications had been made yet, and preliminary autopsies had been done on 16 or 17 bodies, she said. The plane had undergone routine maintenance as recently as Saturday and had 14,500 flight hours, "consistent with aircraft of that age," Bornhorst said. Federal aviation and transportation investigators were at the scene, and Bornhorst said the airline was working to contact relatives of the passengers. Governor Ernie Fletcher cut short a trip to Germany and was returning to Kentucky on Monday afternoon, spokeswoman Jodi Whitaker said. The crash marks the end of what has been called the "safest period in aviation history" in the United States. There has not been a major crash since Nov. 12, 2001, when American Airlines Flight 587 plunged into a residential neighborhood in New York City's Queens borough, killing 265 people, including five on the ground.