One survivor after passenger plane crashes in Kentucky

A packed passenger plane crashed immediately after taking off in Kentucky, killing all but one of the 50 people on board. The sole survivor, a co-pilot, was being treated for critical injuries last night. Investigators were focusing on why the 52-seat aircraft had been directed to a runway considered too short for use by commercial flights.

The aircraft, operated by Comair, a subsidiary of Delta Airlines, went down after taking off from Blue Grass Airport in Lexington, Kentucky, at 6.18am yesterday.

A newlywed couple about to begin their honeymoon were among the 47 dead passengers. Jon Hooker, 27, a promising professional baseball player, and his wife, Scarlett Parlsey, 23, a graduate student, were married the night before they boarding the flight.

A member of the National Transportation Safety Board, Debbie Hersmann, confirmed preliminary data from the on-board flight recorders indicated the plane had taken off from the airport's shortest runway, which is 3,500ft-long. Early speculation centred of whether the runway was too short for a safe take-off with sufficient engine thrust, particularly with an aircraft with a full passenger load.

"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 at that information off and we will be looking at all that," she said.

What remains unclear, investigators said, is whether controllers at the airport had directed the crew of the CRJ-100 regional jet to take off from its longer runway before into an area of fields and woods.

The only survivor, James Polehinke, was the first officer of the three-man crew. He was dragged from the burning aircraft by a policeman and two airport workers and taken to the University of Kentucky hospital.

Comair bought the aircraft from Delta five years ago. First reports suggested that it had remained largely intact after the impact of the crash but that the fuselage had been immediately engulfed in what officials termed a "hot fire"­ a fire that causes significant damage to the aircraft involved.

Several carriers in the United States have become increasingly dependent in recent years on regional jets like the CRJ-100 for routes that no longer justify larger, more fuel-hungry jets. The new generation of commuter jets has gradually displaced less comfortable and noisier turbo-prop aircraft.

Yesterday's accident brings to an end a long period of almost unblemished aviation safety in the United States. The last major crash was in November 2001, when a wide-bodied Airbus belonging to American Airlines came down in a residential area close to John F Kennedy Airport in New York after taking off en route to the Dominican Republic. That accident left 267 people dead.

In a press conference, the president of Comair, Don Bornhorst, said his staff were focusing on assisting the families of those who had died and on determining the cause of the crash. "We are absolutely, totally committed to doing everything humanly possible to determine the cause of this accident," he said.

The crash site was barely a mile from Blue Grass Airport. Experts speculated that the fire that engulfed the plane would have been fed by its full fuel tanks. Local officials said they believed that most of the victims were killed by the heat of the fire, rather than by smoke inhalation or the impact of the crash.

A period of silence was observed at the site and prayers were said before rescue personnel began to remove bodies to a temporary morgue at the airport.