Sunday, April 13, 2014

USS America and the Role of Amphibious Assault Ships

Last Thursday, the Navy accepted delivery of the USS America, the first of the new America class of amphibious assault ships (AAS).  While America is based on the design of USS Makin Island, the last of the Wasp class of AAS's, it departs in crucial ways from the design of earlier ships, having been built to act more like an aircraft carrier than a traditional AAS.  These design choices are controversial, and future ships of the America class may deviate from the "Flight 0" design as new thinking evolves.

America, at 45,000 tons, will be the third largest aircraft carrier in the world, not counting the US Navy's nuclear supercarriers.  It is more fitting even than with most American AAS's to refer to America as an aircraft carrier--significant compromises were made in terms of the ship's role and flexibility in order to enhance her role as a platform for Marine aviation.

Compared to Makin Island, America has 2/3 less space dedicated to hospital and medical facilities, and no well deck.  In return, America has significantly larger hangar capacity and aviation fuel storage, as well as additional aircraft maintenance facilities.  Her standard compliment of aircraft is expected to be 6 F-35B's short takeoff and vertical landing (STOVL) fighters, 12 V-22 Osprey tilt-rotor transport aircraft, 7 AH-1Z Cobra attack helicopters, and 6 transport helicopters, but she could also be outfitted to carry at least 20 F-35B's in a dedicated fighter carrier role.

Problematically, however, the deck of America does not seem capable of actually supporting heavy operation of next generation STOVL and VTOL aircraft, including the F-35B and V-22.  Heat from the engines of both planes have caused major problems with the ship's flight deck, preventing it from being able to carry out much of it's stated role to full effect.  While the Navy claims this will not be a problem as AAS's are designed for short, fast operations rather than sustained warfare, this excuse rings hollow:  it is pointless and wasteful to commission a ship costing over $3 billion dollars which is unable to fully support the aircraft it was primarily intended to service.

AV-8B Harriers, as well as all helicopters, do not pose this problem, but considering the advanced capabilities of both the Osprey and F-35, older aircraft will not be sufficient for many missions that America would expect to face.

The Marines, however, have another concern: the ship's lack of a well deck.  Most AAS's have a large deck at water level at the rear to allow hovercraft and boats to dock with the ship in order to transfer troops and vehicles to shore.  America's lack of a well deck means that all troops must be ferried to shore via aircraft or else be first shuttled to another ship to board landing boats or hovercraft.  This also greatly restricts America's ability to land vehicles in support of infantry or humanitarian operations.

While other ships may be capable of transporting vehicles in a humanitarian crisis, the lack of docking for infantry operations can be more problematic.  In the event of a target still protected by air defenses, landing Marines via aircraft could be much more risky than via boat.  In addition, Marines landed from America will be able to count on fewer fighting vehicles for close support than compared to other AAS's.

America is an impressive ship, with an important role.  Compromises were made in her design, and as her commissioning draws nearer, and after she begins operations, experiences with her initial operation will almost certainly lead to changes in future ships of her class.  What exactly these will be, remains to be seen.

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