<div class='quotetop'>QUOTE </div><div class='quotemain'>LEXINGTON, Kentucky (CNN) -- Federal investigators are trying to determine why a Comair commuter jet took off from a short runway used by private aircraft rather than a longer one for commercial jets before crashing into the woods Sunday near the Lexington airport.Comair Flight 5191 crashed about half a mile past the end of the runway shortly after takeoff Sunday morning, killing 49 of the 50 people on board.The sole survivor, first officer James Polehinke, was in critical condition at a Lexington hospital.The Delta Air Lines commuter flight to Atlanta had been cleared to take off from the 7,000-foot Runway 22 at Lexington's Blue Grass Airport, sources told CNN earlier Sunday.Instead, evidence at the scene indicates the plane took off from Runway 26, which is about half as long, NTSB member Debbie Hersman told reporters Sunday evening. (Watch NTSB describe evidence found -- 1:27)"We're still working on determining what was going on in the cockpit, what information was discussed between air traffic controllers and the pilots," Hersman said. "That's part of our investigation, and we hope to have more information about that later."Hersman would not discuss how or why the plane ended up on the shorter runway. Nor would she say whether the Canadian-built Bombardier CRJ-100 would have been able to successfully take off from a 3,500-foot runway. (Watch results of early NTSB review -- 3:27)But former NTSB Vice Chairman Bob Francis told CNN that the twin-engine jet would have needed about 5,000 feet of runway for a successful takeoff."It sounds like it got barely airborne and came back down, but there isn't really enough evidence yet to draw that conclusion," Francis said. "I can speculate; they cannot."Hersman said investigators are combing through 32 minutes of cockpit voice recordings and "several hundred" readings from the plane's flight data recorder as they search for the cause of the crash.The plane was carrying 47 passengers and three crew members. One of the passengers was an off-duty crew member sitting in the plane's jump seat, Blue Grass Airport Director Michael Gobb said. (Honeymooners among victims)Only the identities of the crew -- pilot Capt. Jeffrey Clay, co-pilot Polehinke, and flight attendant Kelly Heyer -- had been released by Sunday evening.Clay began work with Comair in 1999 and was promoted two years ago to captain, Bornhorst said. Polehinke has worked for Comair since 2002, and Heyer had been employed with the carrier since 2004, Don Bornhorst, the airline's president said.Comair purchased the jet in January 2001 and its maintenance was up-to-date, said Bornhorst. He said the flight crew had been "on a legal rest period far beyond what is required," but the specifics of the crew's schedule will be part of the NTSB investigation. (Watch Bornhorst detail the facts of the crash -- 7:30)NTSB investigators could take up to a year before formally ruling on the cause of the crash.Sunday's crash is the worst U.S. aviation accident since November 2001, when American Airlines Flight 587 crashed shortly after takeoff from John F. Kennedy International Airport in New York.All 260 on board Flight 587 were killed, along with five people on the ground, making it the second-deadliest air crash in U.S. history.</div>Crashed jet used shorter runway
