A federal judge, saying that air passengers do not have to fly aboard DC10s if they don't want to, yesterday refused to order the grounding of the wide-bodied jets until investigators determine the cause of last month's Chicago plane crash disaster.

U.S. District Judge George Hart Jr. said he would not issue an order requested by the Airline Passengers Association, a Dallas-based consumer group representing 50,000 passengers, because it would disrupt flight traffic and the group had not proven that the planes are unsafe.

The Federal Aviation Administration had previously ordered the planes grounded until they were inspected following the Chicago crash that killed 274 persons on May 25 in the worst air crash in U.S. history.

In New York, 13 persons were slightly injured when an American Airlines DC10 made an emergency landing at Kennedy International Airport after a bomb threat was received. Authorities said no bomb was found. The injuries occurred when passingers slid down the planes's emergency chutes after Flight 17, bound for San Francisco, turned back to Kennedy.

In Oklahoma City, a Los Angeles-bound American Airlines Boeing 727 made an emergency stop from full takeoff speed when two tires unders its left wing exploded and burst into flames. Six of the 114 persons aboard were treated for minor injuries after sliding down emergency evacuation chutes onto a runway. Airport fire-fighters put out what they called "a small fire" after the stop.