The National Transportatlion Safety Board has found no evidence of mechanical failure as a cause of the plane crash that killed Governor Mel Carnahan, his son and a campaign aide more than 15 months ago. The National Transportation Safety Board has released thousands of pages of documents, but says its investigation is not done. The NTSB does say, however, there is no evidence of malfunction in the manifold system or vacuum pump. The Carnahan family says in a lawsuit manifold or pump failures caused guidance problems.