the right, and hit on the right landing gear. That gear broke and transmitted the shock to the right wing, which also broke. The plane, which was returning from the Far East after a stop in Anchorage, Alaska, then flipped on its back, rotated 180 degrees and skidded down the runway, erupting in flames.

The two crew members and three others on board escaped by crawling out the captain's side window.

Another problem, the board said, was that FedEx did not tell firefighters at Newark that the plane was carrying hazardous cargo until the fire was nearly out.

Investigators said that the jet could have landed without damage if the captain had not applied power and pulled the nose up.

But, they said, the crew was confused about how long it would take the cargo jet to stop, because the pilots had misinterpreted data from a laptop computer in the cockpit. They believed they had only 780 feet to spare on the runway, but they actually would have had 1,680 feet, using only medium braking effort, the investigators found.

weight of the plane, wind speed, air temperature and other factors. The crew members compared that number to a chart showing the runway length; they did not realize that the computer's number included the "air run" distance from the end of the runway to the normal touchdown point. They therefore tried to touch down before the normal touchdown point, investigators said.

As a result, they were coming down a little too fast. Airplanes are supposed to be descending at two to four feet a second when they touch down. This jet was descending faster than that, but less than 14 feet a second, the maximum the MD-11 can sustain without damage. That assumes, however, the plane is not accelerating downward, as this one was.

Mr. Misencik said that if the pilot had accepted a slightly faster-than-normal descent at first, "it would have been an acceptable landing."

WASHINGTON, July 25 - Federal investigators said today that a Federal Express cargo jet crashed and burned three years ago at Newark International Airport because the crew was confused about how much runway the plane needed to land, and descended too fast.

Those were the first two mistakes in a series of errors leading up to the crash on July 31, 1997, the National Transportation Safety Board found. The captain brought down the three-engine jumbo jet, an MD-11, slightly faster than normal, investigators said, then added engine power and pitched the nose back up at the last moment to slow the descent. As a result, the plane hit the runway and bounced, the board said.

"Unfortunately, the pilot chose the least desirable option," said Paul R. Misencik, a federal investigator and specialist in pilot decisions. Rather than go around for another try, Mr. Misencik said, the crew tried to "salvage a landing in a worsening condition."