The justification process for the Navy's next aircraft carrier was the most extensive in the history of the Department of Defense. The conclusion was definitive: Buy 12 big-deck carriers.
Now that the 109th Congress is considering a law to require the Navy to maintain a force of 12 aircraft carriers, it is the right time to review what the Department of Defense found in the Analysis of Alternatives (AoA) for the CVNX program, why the Clinton administration and the 106th Congress approved a new class of 12 aircraft carriers, and why the Bush administration initially approved the production of the first three of the class now called CVN-21.
For the third time since the Korean War, the Navy had to justify the requirement for aircraft carriers from the bottom up. The Department of Defense required the Navy to put aircraft carrier procurement through the department's process which requires the extensive Analysis of Aternatives. The analysis centered on the idea that two smaller carriers, together operating the same number of aircraft as one large carrier, offer advantages over the one. Analysis found that large, big-deck carriers are safer, more effective, more cost efficient, and more survivable than smaller aircraft carriers in putting the same number of aircraft to sea, including short take-off and vertical landing (STOVL) aircraft.
As defined by the Navy and approved by the Joint Chiefs, the critical capability of the aircraft carrier is that, independent of land bases, it must be able to fly aircraft in sustained combat operations that can simultaneously perform three missions: survey and know the batttlespace, control and dominate the battlespace, and attack the enemy on or under the sea and on land.
This author led the Future Carrier Program Office that conceived and examined carrier designs to support an evaluation of alternatives conducted by the Center for Naval Analyses. We looked at small carriers operating 40 aircraft, medium-sized carriers with 60, and large carriers with 80. Most of the air wings considered used conventional (CTOL)—catapulted takeoff and arrested landing—aircraft, some consisted solely of STOVL aircraft, while the remainder had a mixed complement. We looked at 75 ship designs with different types of propulsion-diesel, gas turbines, and nuclear power-with varying numbers of plants and different combinations of auxiliary and defensive systems on different hulls. This was the most extensive AoA in the history of the defense department.
Safety
The larger carrier is less affected by the ocean and has a larger flight deck higher above the water's surface that remains dryer than smaller ships. Such flight decks are much safer to operate aircraft. In the 1970s when the Navy operated both medium (60,000 tons) and large (80,000+ tons) carriers, the then-Chief of Naval Operations testified that medium carriers suffered three times the aircraft accident rate of large carriers. The North Atlantic sea state limits a medium-sized carrier's aircraft operations to 58% of the time compared to 90% for a large carrier. The percentages are similar for other oceans. With STOVL aircraft, a large carrier provides a more stable deck and more parallel queues for launching and landing aircraft that can generate more—but only a few more-sorties than conventional operations. One large aircraft carrier, therefore, whether operating STOVL or CTOL, can operate more aircraft and more safely than two smaller carriers.
Effectiveness
Aircraft carriers launch and recover aircraft, each combination of which constitutes a sortie. An aircraft carrier's effectiveness is measured by how many combat-ready aircraft it can sortie.
The evaluation included looking at the effectiveness of various carriers with air wings of 40, 60, and 80 aircraft of the 2015 timeframe (JSF and F/A-18 E/F fighters, etc.) in a hostile air-threat environment similar to what the British experienced in the Falklands War. We found that the carriers with 40 aircraft were completely defensive against such a threat and could not generate offensive strike sorties while the medium and large carriers could. Small carriers capable of carrying only 40 aircraft did not meet the Joint Chiefs' critical capability for an aircraft carrier and were dropped from consideration.
The ships' effectiveness was next studied with 60- and 80-aircraft air wings in the most demanding scenario the department could envision: a hostile regime seized control of and sealed off the Persian Gulf. Four carrier strike groups, starting from different points around the world, speed to the gulf and fight their way in. In this 28-day scenario, the four medium carriers generated 4,000 strike sorties while the four large ships launched 8,000 sorties. The difference in cost between the large and the equally robust medium carrier was 8%. Effectiveness doubled for—with the cost of the air wing—13%.
We then examined the effectiveness of the mediumsized air wing from large carriers in the same scenario. We found that 60-plane air wings flying from large carriers generated 5,600 strike sorties, a 40% improvement by going to the larger platform. A larger flight deck allows more aircraft on the deck and for them to get airborne quicker. The larger weapons magazines and fuel capacity of the bigger ships allow them to stay on-line longer and go off-line less to refuel and re-arm.
The significant improvement of the medium air wing off a large carrier was the key finding of the CVNX Analysis of Alternatives. An unofficial but often stated premise is that the Department of Defense cannot afford all the aircraft for all the large aircraft carriers, so why buy large carriers? This has more to do with the cost of the aircraft than the cost of the carrier. A full complement of aircraft costs twice that of the carrier. When the less-than-full air wing effectiveness increases because of the large carrier, the value of that ship is apparent. It can operate effectively with less than a full complement of aircraft. It can tailor its air wing with more aircraft for a specific mission. For instance, if the small boat threat in the Persian Gulf was to increase, the carrier could put more helicopter gunships in the spare deck spots to counter that threat. If the submarine threat in the Yellow or Arabian seas should increase, the carrier could add more sub-hunting aircraft. If Osama Bin Laden is found in a cave deep in the mountains of Afghanistan, extra aircraft and tankers required for the deep strike mission can be added virtually overnight. Should circumstances dictate more aircraft on the carriers, the spots will be there with the bigger decks. Large carriers provide far more flexibility than smaller ones.
Economy and Survivability
The small 8% cost difference between similarly equipped medium and large carriers lies in the robustness of their systems. The carriers may be small, medium, or large, but the cost is nearly the same for major elements, such as the propulsion plants, catapults and arresting engines, aircraft and weapons elevators, command/control electronic systems, and air wing avionic repair suites. The economy of scale is what makes large carriers more cost efficient than smaller carriers.
A smaller, austere carrier can be built for about half the cost of a large carrier. Many of the 75 designs included such austere ships, but they exhibited serious flaws. Typically a large carrier has four independent propulsion plants powering four shafts, an elaborate armor system, and four each of catapults, arresting engines, and aircraft elevators. A carrier with two shafts and propulsion plants must give up the weight of its built-in armor system to steam fast enough to launch aircraft. It will not have the speed should an engine fail; an infrequent but possible occurrence that must be considered in any warship design. Further, with the large load of aviation ordnance and fuel, it would be unwise to eliminate the armor. A large aircraft carrier provides the space and volume to house vital redundant systems, and its large mass combined with its armor gives it greater capacity to absorb the energy of attacks. Large carriers are more survivable than smaller ones.
Power
Nuclear power and naval aviation is a match made, not in heaven, but on earth where 73% of its surface is water. A nuclear-powered carrier can steam around the world more than 60 times before refueling while an oil-fired carrier must refuel during one ocean's transit. Nuclear power inherently doubles the amount of aviation fuel carried because all fuel tank volume can be dedicated to the air wing. It also increases the weapons magazine capacity by 30% because of the nuclear plant's smaller volume. Moreover, if the carrier is powered by gas turbines, 300,000 cubic feet must be dedicated solely to air intakes and exhaust trunks.
The requirement by the Joint Chiefs for a long time has been 15 large-deck aircraft carriers. At the end of World War II, there were 24 fleet carriers. There were just eight carriers at the start of the Korean War, and 18 by its end. During the Vietnam War the maximum force consisted of 16 ships. There were 13 from 1976 to 1981, 14 from 1982 to 1992, and 12 since 1994.1
The rough requirements are that, at any given time, the world situation has three aircraft carriers forward deployed. With three ships recently off deployment, and three working up for deployment, the remaining three can be in depot maintenance of various lengths. In recent crises, six were deployed for Desert Storm, four for Afghanistan, and six for Iraqi Freedom. The need to deploy six aircraft carriers in a crisis and three at any given time, determines the 12-ship force level.
The administration is considering reducing the carrier force because of money. The runaway costs of the war in Iraq is pinching the Department of Defense and aircraft carriers are expensive. The payroll for the ship's company alone is hundreds of millions of dollars per year. A new aircraft carrier costs more than $6 billion to build and its air wing twice that. Cutting a carrier saves a lot of money.
Once a carrier is cut from the force, however, it is not easily regained. It takes 12 years to increase the force with one new carrier while it takes only one year to reduce it by one or more. Once put in mothballs, they are very hard to be-and have rarely been-brought back into service.
The large, big-deck aircraft carrier with its aircraft is to many minds the most potent and flexible weapon system ever devised. Though built for the long haul, they are readily adaptable to the rapidly transforming aircraft evolving against new threats. Aircraft carriers are the last weapon system the administration should cut in this time of war. The congress has the power to support and maintain the Navy and should support and maintain 12 aircraft carriers. Get on with building the CVN-21.
1 Ronald O'Rourke, Congressional Research Service Report 32731. 14 January 2005.
Captain Manvel, a 1972 graduate of the U.S. Naval Academy, served aboard three aircraft carriers and assisted in supervising the construction of two others. He was the first program manager of the CVNX, now CVN-21.