America-class amphibious assault ship

The America-class amphibious assault ships (formerly the LHA(R) class) of the U.S. Navy was designed to put ashore a Marine Expeditionary Unit using helicopters and MV-22B Osprey V/STOLs, supported by AV-8B Harrier or F-35 Lightning II V/STOL fighter planes and various attack helicopters. The first of these warships should be delivered to the U.S. Navy in 2013 to replace the USS Peleliu (LHA-5) of the Tarawa-class amphibious assault ships. The design of the America class was based on that of the USS Makin Island (LHD-8), the last ship of the Wasp class, but the "Flight 0" ships of the America class will not have well decks, and they have smaller on-board hospitals in order to give more space for aviation uses.

Although they only carry helicopters and V/STOL aircraft, the USS America with a displacement of about 45,000 long tons is similar in size to the fixed wing aircraft carriers of France and India.

The America can be used as a small aircraft carrier with a squadron of jet fighters plus several multipurpose helicopters, such as the SH-60 Seahawk. She can carry about 20 AV-8B Harriers, F-35Bs, or a mixture of the two, but the future ships of this class, starting with LHA-8 will have smaller aircraft hangars to leave room for smaller than usual amphibious warfare well decks.

Design
The design of the USS America is based on the USS Makin Island (LHD-8), herself an improved version of the Wasp-class amphibious assault ships with gas turbine power. About 45 percent of the "Flight 0" design of this class is based on that of the Makin Island, but with her well deck omitted to allow more room for aircraft, their spare parts and weapons, and their fuel. Note that the gas turbines of the Makin Island, the America, and her possible successors burn the same kind of fuel (JP-5) that is burned in the gas turbines of their helicopters, the jet engines of their AV-8B Harrier fixed-wing attack planes, the engines of the MV-22 Osprey aircraft that they can carry, and (in future ships), the gas turbines of the Landing Craft Air Cushions (LCACs) that they could carry in their well decks. All of this greatly simplifies the storage, distribution, and use of the fuels for these craft.

The typical aircraft complement for the first two vessels is expected to be 12 MV-22B Osprey transports, six STOVL F-35B Lightning II multirole jet aircraft, four CH-53K heavy transport helicopters, seven AH-1Z/UH-1Y attack helicopters, and two Navy MH-60S Knighthawks for air-sea rescue. The exact make-up of the ship's aircraft complements will vary according to her mission. She can carry about 20 AV-8Bs or F-35Bs, and two MH-60Ses to serve as a small aircraft carrier as demonstrated by Landing Helicopter Dock (LHD) operations in Operation Iraqi Freedom.

Any further warships in this class will also have a well deck for amphibious warfare in their sterns to contain landing craft (such as the Landing Craft Air Cushion (LCAC) exactly as in the Tarawa-class amphibious assault ships (LHA)s and the Wasp-class amphibious assault ships.

The addition of a well deck will leave less space for aircraft on board the ships, but the "Early Operational Assessment" of 2005 criticized the "Flight 0" design because the expanded aviation facilities gave no space for a well deck. Also, the USS America has reduced stowage space for military vehicles, and the size of her hospital was reduced by two-thirds with respect to the Wasp-class ships.

Before he became the Under Secretary of the Navy, Robert O. Work, also brought into question the usefulness of an amphibious warfare ship without a well deck. The concept of the Landing Platform Helicopter (LPH) had failed when their helicopters met antiaircraft systems off the coast of Lebanon during the late 1970s. In that case, Marines had to be moved first onto the warships that had well decks.

The U.S. Marine Corps is now more concerned about anti-ship missile attacks from fast attack craft, hence the Commandant of the Marine Corps wants to keep the amphibious ships farther offshore. In that case Marines would be sent ashore in long-ranged MV-22 V/STOL aircraft. The MV-22 is significantly larger than the largest helicopters used by the Marine Corps and the Navy in the past. Hence, the America has twice the displacement of the much older Iwo Jima-class amphibious assault ships (all of which are now decommissioned).

Setting the beam of the America at 106 feet is dictated by the need for these ships to pass through the Panama Canal. The Congressional Budget Office found that LH(X)-class ships would be more cost-effective if they were built with nuclear power—if the price of oil reached and stayed above $140 per barrel by 2040.

A modified version of the design of the USS America, designated the MPF(F), LHA(R), or T-LHA(R), was proposed for two ships of the Maritime Prepositioning Force (Future). The MPF(F) is the Navy's concept for a "sea base" to support operations ashore starting in about 2025.

These two ships would hypothetically be manned by a civilian crew from the Military Sealift Command, and hence not armed with weapons. Funding for the MPF(F) and the LHA(R) was tabled by the Senate Armed Services Committee in the fiscal year 2008 budget. The U.S. Navy now intends to buy more ships of the America class for its fleet of amphibious warfare ships.

The so-called "LHX" was a warship that was proposed in the late 1990s to replace the Tarawa-class ships, but with a dry deck for hovercraft rather than a floodable "well deck". After the year 2000, the LHX, the so-called "Amphibious Assault Ship Future Replacement", was put forward to replace all of the LHDs.

The new LHX could be a Flight 2 design of the America class built with a well deck and a smaller island superstructure, which would give it 20 percent more capacity on the flight deck. This would remove the current restriction on MV-22s to land on spots 5 and 6, and also giving room for four MV-22B, three F-35B Lightning IIs, or three CH-53Ks to use the flight deck. In 2008, the procurement of Flight 2 ships was tentatively planned for 2024, but that might not be practical or affordable by then.

The America-class amphibious assault ships are engineered with a hybrid-electric propulsion system derived from the one used on the USS Makin Island (LHD-8). The ships can use diesel-electric propulsion for slow speeds and use gas-turbines for high speeds. The amphibious ships can utilize the diesel-electric engines when operating close to shores in situations that require lower speeds.

History
The program started in July 2001, with development beginning in October 2005, the production decision was made in January 2006, and construction of LHA-6 began in December 2008. The keel-laying ceremony was on 17 July 2009 with delivery originally planned for August 2012. As of 2009 delivery was planned for February 2013 and initial capability for February 2014, but delivery has now been further delayed into FY2014.

Northrop Grumman Shipbuilding was awarded $48.1m for "additional planning and advanced engineering services in support of the LHA replacement (LHA[R]) Flight 0 amphibious assault ship (LHA 7)" on 28 October 2010, to run until May 2012. It is tentatively scheduled for delivery in 2017. In January 2011 development problems led to the F-35B program being placed on probation for two years, and plans for LHA-7 could change if the F-35B is canceled.

In April 2012 Contract N00024-10-C-2229 was issued to Huntington Ingalls Industries, in which funding for steel plate purchase for LHA-7 is planned, and announced requirement for additional four ships (to LHA-10). LHA-7 will be laid down in April 2013 and her commission is planned in 2018.

Secretary of the Navy Ray Mabus announced May 4 the selection of USS Tripoli as the name for the Navy's next large-deck amphibious assault ship (LHA-7).