WARWICK, R.I. (AP) – A preliminary investigation by the National Transportation Safety Board finds a hard landing is among the factors that led up to a plane sliding off the runway at T.F. Green Airport earlier this month.

The U.S. Airways Express flight from Philadelphia was carrying 31 passengers and three crew members on December 16 when it slid off the airport’s primary runway. No one was injured.

The NTSB says a light rain and mist were reported at the time and that the runway was believed to have been wet.

Bill English, the NTSB investigator studying the incident, says the pilot reported that the plane started bouncing after it touched down. But English says he believes the pilot was mistaken and that the sensation he reported was actually the landing gear collapsing.

AP-ES-12-27-07 1456EST