Northrop Grumman Corporation has finished installing the propellers on the nation's tenth and final Nimitz-class aircraft carrier, George H. W. Bush (CVN 77). The carrier is under construction at Northrop Grumman's Newport News sector, the nation's sole designer, builder and refueler of nuclear-powered aircraft carriers. The George H. from previous Nimitz-class carriers. but the blades are shaped differently to reduce wear and erosion. Northrop Grumman. and complex overhaul. Other new design features for the George H. and a new underwater hull-coating system. The George H. buoyancy to the forward end of the ship and improves hull efficiency. The ship's keel was laid Sept. 6, 2003. October 2006 with delivery to the U.S. Navy in late 2008.