The plane crash in Malaga, Spain, that killed 55 people Monday could have started when a tire blew out on the nose wheel of the McDonnell Douglas DC10 as it was speeding down the runway toward takeoff, U.S. government sources said today.

They based that speculation -- and clearly labeled it as such -- on the two facts: pieces of the nose tire have been found about 4,000 feet down the 10,499-foot runway and the pilot reported vibration in the airplane as the reason he chose to abort the takeoff.

The tire could also have failed because of heavy braking after the vibration was noted, experts said. Tires usually blow out when takeoffs are aborted at high speeds, particularly when the planes are heavily loaded.

There are heavy tire marks on the last half of the runway and ruts in the ground off the end where the Spantax charter flight crashed through an instrument shack, the airport fence, and vehicles on a road before coming to rest in a field. The plane, scheduled for New York, carried 393 people including 13 crew members.

Sources believe the plane did not leave the ground, as was suggested in early reports. At the time of takeoff it was estimated to weigh 527,000 pounds, well under the legal limit of 575,800 pounds. The speed at the time braking probably began was estimated to exceed 160 knots (184 miles per hour).

A nose wheel tire failure could be a controllable situation, according to U.S. DC10 experts, who were as puzzled by the reported actions of the pilot as they were by the reported performance of the aircraft.

Normal procedure if a tire or an engine fails at takeoff speed would be to lift the nose off the ground, continue the takeoff on two engines if necessary, assess the damage, call the fire department, then attempt a landing after dumping fuel to lighten the load and lessen the consequences of fire.

Sources stressed that the information is spotty. Much technical data remains to be analyzed before conclusions can be drawn.

Investigators have learned preliminarily that all three of the engines on the aircraft appeared to be functioning normally, contrary to some early reports. The center engine, in the tail section that broke loose from the rest of the plane, was not damaged by the crash and was still "windmilling" after the accident, sources said.

The U.S. delegation to the accident officially reported there was "no mechanical failure of the DC10 wing, engine or" engine mounting when the right wing engine fell off the plane. That separation was caused by impact with a concrete structure, the delegation said. The left wing engine stayed with the wing.

There is no evidence any of the engine parts broke loose from the engine cases, which, according to federal records, has happened nine times on DC10s powered with General Electric CF6 engines, as this plane was.

The Federal Aviation Administration recently ordered a more rigorous inspection schedule of the CF6s until a new, longer-lasting disc in the engine can be installed. Some engines have been refitted, but a spokesman for General Electric said he did not know the status of the Spantax charter plane engines.

The engine under the right wing broke away because of impact damage, as did all four main sections of the extended landing gear, government and industry sources said.

Flight attendants -- three of whom were killed -- reportedly had difficulty persuading some of the passengers to abandon their souvenirs and personal belongings before fleeing the cabin, a recurring problem in accidents.

Whatever the final cause, the accident is a another blow for McDonnell Douglas and its DC10. "Any accident always hurts a manufacturer," McDonnell Douglas spokesman John Cooke said today. "How extensively or how long is hard to say."

A DC10 crashed near Paris in March, 1974, and killed 346 people in what remains the worst single-plane accident in history. It was attributed to a design problem in a cargo door which has been corrected.

An American Airlines DC10 crashed on takeoff from Chicago in May, 1979, and killed all 273 on board to become the nation's worst crash. The cause was later established to be a maintenance failure, but only after months of speculation about the basic aircraft design.

Of perhaps more pertinence to the Spantax accident are two little-publicized U.S. incidents. In March, 1978, the pilot of a Continental Airlines DC10 aborted his takeoff on a wet runway at Los Angeles International after both tires on the left main landing gear failed just as he reached takeoff speed. The plane overran the runway and fire broke out. Two of the 184 passengers were killed.

In November, 1975, the pilot of an Overseas National Airways charter aborted a takeoff from Kennedy Airport in New York after seagulls flew into one of the engines and stopped it. Brakes failed, tires blew out and the plane was destroyed by fire. However, everyone on board was an airline employe experienced in rapid evacuation. There were no fatalities.

These are difficult times for airplane manufacturers generally. There are about 100 used jumbo jets on the market, at least 15 of them DC10s, and few buyers because of the recession. An accident is particularly damaging to a manufacturers' sales efforts in foreign markets, industry sources said.

A total of 370 DC10s have been delivered, 361 to airlines and nine to the Air Force as KC10 tankers.