Cranes in a muddy field began hoisting engines from the wreckage of a Delta jet Saturday as investigators met to resolve contradictions in accounts of events leading up to the crash that killed 13.

"There are a lot of inconsistencies and a lot of questions that need to be answered, and obviously we're going to get the answers as quickly as we can," said Lee Dickinson Jr., a member of the National Transportation and Safety Board team.The three Pratt & Whitney JT-8D engines from the Boeing 727 that crashed Wednesday will be sent to the manufacturer for inspection, NTSB investigators said.

Some 30 people in hip boots and bib overalls slogged through ankle-deep mud at the crash site Saturday afternoon while they removed the engines and looked for other clues to the cause of the crash of Delta Flight 1141.

Ninety-five people survived when the plane, en route to Salt Lake City, crashed and burst into flame on takeoff from Dallas-Fort Worth International Airport.

The accident represented the first real-life test of a plane fitted with seats and carpets made of new fire-blocking materials required by the Federal Aviation Administration, experts said.

While it is not known how large a role the fire-resistant materials played in buying time for the 95 survivors, they may have helped, said John Mazor, spokesman for the Air Line Pilots Association in Washington.

"Just looking at the airplane - the scorch marks and the way it broke up on impact - typically you might have expected a greater number of fatalities out of an accident like that," he said. "We won't know how we were so lucky until we get more factual information and some analysis."

The wreckage was visible to passengers of planes landing or taking off, but its Delta logo had been covered with white paint Saturday.

Funerals for three of the victims were scheduled for Saturday. Services were held Friday for a Dallas couple and a veteran Delta flight attendant.

The NTSB teams concentrated on inconsistencies regarding the plane's wing flaps and engines.

Evidence has not yet confirmed witness' accounts that the engines trailed flame during takeoff, said Bernard Loeb, NTSB deputy director of investigations.

No signs of damage have been found on any of the engines, which will be shipped to Pratt & Whitney in Hartford, Conn., investigators said.

Although cockpit instruments told crew members that the wing flaps were in proper position for takeoff, inspections of the wreckage found that the flaps and slats appeared to be in the opposite of the correct position, investigators said.

NTSB officials said locking devices on the slats probably would have prevented them from being knocked out of position during the crash.

Flight engineer Steven Judd, interviewed in his hospital room Friday, told investigators he remembered pilot Larry Davis saying, "15 15 Green," indicating the instruments showed the flaps were at the proper 15 degree angle for takeoff, Dickinson said.

Davis, 48, was in fair condition at Parkland Memorial Hospital, but Dickinson said Davis' doctor had not given investigators permission to talk to him. "My information is he is not medically fit to talk to," he said.