The last transmission received from Flight 2311 was to the ASA manager at the airport, who reported that the flight made an “in-range call” on the company radio frequency and that the pilot gave no indication that the flight had any mechanical problems. Witnesses reported seeing the aircraft approaching the airport in visual meteorological conditions at a much lower than normal altitude. Several witnesses estimated that the aircraft flew over them at an altitude of 100 to 200 feet above the ground.