Were the USS America to cruise alongside the French nuclear-powered aircraft carrier Charles de Gaulle, the average Joe might struggle to distinguish their purposes. Both flat-tops measure longer than two-and-half football fields in length and carry jet fighters and helicopters.
But the America and her sistership Tripoli are technically “Landing Helicopter Assault” vessels numbered LHA-6 and LHA-7 respectively: super-sized members of the “gator navy” of amphibious assault ships designed to deploy the expeditionary units of the U.S. Marine Corps onto hostile shores. In addition to the Navy crew of 1,000-1,200 sailors and officers, each LHA can carry nearly 1,700 Marines.
Unlike the catapult-launched Rafale-M jet fighters on the Charles de Gaulle, the America and Tripoli can only deploy short-takeoff and vertical-lift capable jump jets from their decks. You can see a video of an F-35B hovering down for a landing on the America here.
Rather than using nuclear reactors to achieve brisk speeds of 30 knots, 45,000-ton LHAs use an innovative hybrid electric/gas-turbine propulsion system pioneered in the final Wasp-class LHD, USS Makin Island. The electric propulsion is used for slower cruising speeds while the gas-turbine becomes more efficient near the more modest maximum speed of twenty knots.
However, unlike the Wasp-class Landing Helicopter Docks (LHDs) they were based upon, America and Tripoli lack floodable “well deck” which can carry landing craft to ferry troops ashore. (This video shows how the Wasp’s cavernous well deck works.)
All that space has instead gone to dramatically expanded aviation facilities and fuel stores. The ship’s medical facilities were also reduced by two-thirds.
Instead of watercraft, the LHAs rely on squadrons of MV-22B Osprey tilt-rotors, sophisticated hybrid aircraft combining the vertical lift ability of a helicopter and the speed and range of an airplane—to insert troops by air.