(Reuters) – The U.S. Coast Guard was searching an area four miles (6 km) off the Outer Banks of the North Carolina coast for a plane that crashed into the Atlantic Ocean with eight people aboard, finding some debris in the water but no signs of life, officials said. The Pilatus PC-12 single-engine passenger plane went down on Sunday afternoon, prompting a search that included a lifeboat crew, helicopter, C-130 aircraft and other assets, Coast Guard spokesperson Edward Wargo said. A U.S. Marine Corps air traffic controller reported that the plane was seen behaving erratically on radar then disa…