Amphibious Assault Ship
From Citizendium, the Citizens' Compendium
An Amphibious Assault Ship (LHA or LHD) are the largest type of U.S. amphibious warfare ship, which carries a large number of troops, and can operate helicopters from its flight deck. Such vessels may or may not have have the well deck characteristic of a Landing Platform Dock, so landing craft cannot be loaded internally and then sail out under their own power. These large vessels, however, trade off much more cargo and passenger space for the well deck.