The Northwest Cargo B747-200 sits off the end of runway 24R at Anchorage International Airport. The vehicles visible in the lower right corner of the photograph mark the end of the runway.

A Northwest Airlines 747 cargo jet aborted takeoff and ran off the edge of the runway at Ted Stevens Anchorage International Airport early Sunday morning, coming to rest just a few hundred feet from West Northern Lights Boulevard and the bluff above Knik Arm.

The jumbo jet's landing gear dug into muddy ground off the northern edge of the north-south runway, and most of its 18 tires appeared flattened after it screeched to a halt just after midnight.

The three-member crew was uninjured, said Northwest spokeswoman Kathy Peach, in Minneapolis. She would not release the names of the crew members Sunday.

According to airport operations manager Corky Caldwell, the freighter was taking off about 12:30 a.m., loaded with 794,000 pounds of cargo. The jet was bound for John F. Kennedy International Airport in New York City.

As the plane rolled north on the 11,600-foot runway, "the pilot reported hearing some loud thumping sounds," Caldwell said. "As a precautionary measure he aborted the takeoff."

The plane stopped about 300 feet off the edge of the asphalt runway. Another 300 feet farther, and it would have hit the airport fence. Beyond the fence is a 50-foot drop to West Northern Lights, the bike trail and silty, icy Knik Arm beyond that.

Caldwell said airport crews immediately rushed to the scene with rescue equipment.

"We don't appreciate it happening, but the crew did exactly what it was supposed to do," Peach said.

Fuel was taken off the aircraft first. Then crews unloaded cargo. Caldwell said help came from Kulis Air National Guard Base with special vehicles that could heft heavy loads across the soft ground that the jet was mired in.

Peach said she didn't know exactly what the cargo contents were but said there was nothing hazardous.

Sunday, National Transportation Safety Board and Federal Aviation Administration investigators and local Northwest officials were at the site surveying the damage. Investigators would not speculate Sunday what the thumping noise was that the pilot heard.

Across the road, curious passers-by stopped to watch and take pictures.

A team of about 13 Northwest mechanics from Minneapolis and Seattle were on their way to Anchorage on Sunday with an aircraft recovery kit, consisting of special jacks, new tires and other equipment, Peach said. The jet will have to be lifted so that many of its tires can be changed and it can be rolled out of the way.

That operation could take a few days, meaning all airport traffic will be using the east-west runway, Caldwell said. That means extra noise and vibration for surrounding neighborhoods until at least midweek, he said.

Airport statistics show Northwest cargo jets average about 46 landings a week at Anchorage. Total cargo jet traffic at Anchorage is a little more than 500 a week.