Vincent Laforet/The New York Times Lt. Dewaine Barnes, who became a pilot after learning about the Tuskegee Airmen, is aiming to lead a team in combat. ABOARD THE U.S.S. ABRAHAM LINCOLN, in the Persian Gulf, March 28 — After all the briefing, the training, the flying, the waiting, the war with Iraq has not unfolded as Lt. Dewaine Barnes had anticipated. The campaign started unexpectedly with the cruise missile strike aimed at killing Saddam Hussein. The dedicated air war, dominated by precision-guided bomb strikes, shifted within just days to a riskier scenario that focused on close air support for fast-advancing...