** ADVANCE FOR WEEKEND OF AUG 25-26, 2007 -- FILE ** Lexington Police Officer Adrienne Thomasson guards the wreckage of Comair Flight 5191 at Blue Grass Airport in Lexington, Ky. in this Aug. 29, 2006 file photo. In the year since a commercial jet tried to depart from a too-short runway at Blue Grass Airport, clipping trees and a fence before crashing and killing 49 of the 50 on board, some safety changes followed. But others may take years. At least two companies have developed cockpit technology to warn pilots about runway incursion. But while there has been increased interest since the Kentucky crash, it's still not mandated by the federal government. (AP Photo/Ed Reinke, File)