An American Airlines jet en route to San Jose from Seattle made a emergency landing in Eugene, Ore., after the craft began vibrating, aviation officials said. The Boeing 737-200 landed safely at 8:12 a.m., a Federal Aviation Administration spokesman said. None of the 31 passengers and four crew members were injured. The FAA spokesman said the plane was about an hour out of Seattle when the pilot radioed the Eugene tower and reported “the whole aircraft” was vibrating. An American Airlines spokesman said the jet was acquired last year when American took over Air Cal. It was taken out of service after it landed, he said. The problem appeared to be in a rudder used to turn the aircraft, he said.