Forty-three people were injured - one suffering a broken neck - when a Boeing 747-400 of the US company Northwest Airlines plunged briefly in violent turbulence off the Japanese coast Friday, according to dpa. They quoted witnesses as saying the aircraft, arriving from Manila and in a holding pattern prior to landing at Tokyo's Narita airport, suddenly plunged and then immediately regained its altitude, causing chaos on board. Passengers who had ignored the fasten-seat-belt signs were hurled against the cabin ceiling and back to the floor. "It happened so fast, then it was over," one passenger was quoted as saying. A Japanese Transport Ministry spokesman said the pilot had not informed air traffic control that there was turbulence, or that there were injured passengers on board among the 408 passengers and 14 crew. The airline said the fasten-seat-belt signs had been on at the time. Japanese television showed pictures of medical crews tending to passengers after the aircraft landed at Narita half an hour later.