General Dynamics announced that David K. Heebner, president of General Dynamics Land Systems, will succeed Michael W. Toner as executive vice president and group executive for the corporation's Marine Systems group when Toner retires on December 31, 2008. Mark C. Roualet, senior vice president and chief operating officer of General Dynamics Land Systems, will succeed Heebner on October 15, at which time Heebner will transfer to the corporation's headquarters for a transitional period. Heebner, 63, has been president of General Dynamics Land Systems since July 1, 2005. Previously he had been senior vice president - planning and development for General Dynamics, since March 2002. He had been vice president of strategic planning for General Dynamics since January 2000.