On Tuesday, the NTSB said it has determined that the probable cause of the crash of a Beech King Air operated by Hendrick Motorsports was the flight crew's failure to properly execute the published instrument approach procedure. A contributing cause was the crew's failure to use all navigational aids to confirm and monitor their position during the approach. The King Air collided with mountainous terrain in October 2004 during a missed approach to Martinsville/Blue Ridge Airport, in Virginia. All eight passengers, some of them Hendrick employees, and both flight crewmembers died. The flight had departed from Concord (N.C.) Regional Airport, operating on an instrument flight plan. Radar data shows that after the crew was cleared for a localizer approach to Runway 30 at Martinsville, the airplane did not descend at the proper point. About seven miles beyond the airport, the airplane began a straight-ahead climb. The airplane's radar target was lost. The missed approach should have occurred over the Martinsville Airport by executing a climbing right turn, the NTSB said. "The approach and missed approach procedures provide for safe operation in instrument weather conditions," said NTSB Acting Chairman Mark Rosenker. "It is imperative that pilots use all available navigational aids to ensure that the approach is properly flown." The airplane was not equipped with a ground proximity warning system. The final report will be published in three or four weeks, The Associated Press said.