On February 1, 2006, at 0940 eastern standard time a Piper PA-31-350, N3581C, registered to and operated by Labcorp, Inc., operating as a 14 CFR Part 91 corporate flight, collapsed the left main landing gear during landing at the Burlington-Alamance Regional Airport, Burlington, North Carolina. The airplane received substantial damage. Visual meteorological conditions prevailed and an instrument flight plan was filed. The Airline Transport Pilot was not injured. The flight originated from Manassas Regional Davis Airport, Manassas, Virginia on February 1, 2006, at 0840. The pilot stated he entered a left downwind for runway 06 and extended his downwind due to another airplane being on left base for the same runway. He turned final and made several s-turns while waiting on the other airplane to clear the runway. Once the other airplane cleared the runway the pilot stated, "I lined up with the runway 06 and flared to land. My main landing gear struck the end of the pavement and sheared the left main gear." The pilot did not report any mechanical problems before the accident.