A small twin-engine plane crashed into the Superstition Mountains east of Phoenix, the largest city of the US State of Arizona, last night and there was no apparent sign of survivors, authorities said. There were no signs of any survivors among the six people who were on board the plane, which ignited a wildfire when it crashed, Elias Johnson, a spokesman for the Pinal County Sheriff''s Office, said. The plane involved was a Rockwell AC69 that took off from Falcon Field, in the Phoenix valley, Allen Kenitzer, a spokesman for the Federal Aviation Administration, said. The crash occurred near a remote summit in the Superstition Mountains called Flat Iron, Johnson said. The Superstition Mountains are 45 miles east of Phoenix. An officer with the Arizona Department of Public Safety was dropped into the area by helicopter to assess the situation, and a 12-person search and rescue team will make a hike of about six hours to reach the crash site, Johnson said. The plane was registered to Safford, Arizona-based Ponderosa Aviation, which is an air charter firm. It has eight full-time pilots and has been in operation since 1974, according to the company''s website.