This uncertainty, combined with the rising costs of new generation carrier programs (the unit cost of the US’ Gerald Ford-class carriers is close to $13bn, against $8.5bn for the Nimitz-class…), has triggered a rethink of different ship concepts for the future, aiming to cut costs just as much as to adapt to the various threats mentioned above. As the U.S. Navy's oldest Nimitz-class aircraft carriers approach retirement, and the Gerald Ford-class carrier program begins to deliver, discussions about the suitability of these supercarriers for some lower-end missions are emerging. Some argue that the addition of smaller, lighter carriers to the fleet would be welcome.
Let’s note first that a so-called “light carrier” is not easy to define, especially in the US context. While the US Navy claims it “only” operates ten carriers, the pair of USS America class vessels currently in service are considered as “amphibious assault ships”. Their dimensions, however, would undoubtedly qualify them as aircraft carriers in any other country throughout the globe: they are 257-meter long for a beam of 32 meters, and weigh 45,000 tons, roughly the same dimensions as the French Charles de Gaulle (except for the beam, which is twice as large). The same can be said of the seven Wasp class landing helicopter docks (LHD) currently in service, branded as amphibious assault ship with a size and weight only slightly inferior to the America class vessels.
Therefore, for the sake of clarity, “light” carriers will refer here to smaller platforms, weighing up to 30,000 tons —an arbitrary threshold, but one that helps distinguish US contemporary standards from the dilemmas faced by smaller states, which often have only one aircraft carrier in their fleet (if any), and have shown an interest in light carriers.
From an historical standpoint, light carriers are nothing new. They go as far back as World War II, with the Independence-class aircraft carriers built in emergency for the US Navy out of light cruisers that were then already under construction. During the same period, the Essex class illustrated the US Navy’s clear preference for large platforms, able to carry more fuel, personnel and weapons; the Independence-class carriers displaced 11,000 to 15,000 tons, and were 190 meters long, for a beam of 33 meters.
Despite their good service record during the war (the Independence-class represented more than 25% of the Navy’s carrier striking power in the Pacific by 1945), the majority of these so-called CVLs (for “conventionally powered light aircraft carrier”) were decommissioned in 1947, although some of them were reintegrated during the Korean War. Others were sold to allied countries, like France, Spain.
By the early 70s, the Independence class had been stricken from the Naval Vessel Register, and no CVL program was ever launched again in the US. Hence the mitigated reception, in 2017, of Senator John McCain’s proposal to create “a new ‘high/low mix’ in the Navy’s aircraft carrier fleet”, arguing that “the Navy should begin transitioning from large deck amphibious ships into smaller aircraft carriers.”
Converted amphibious destroyers vs. CVLs.
In the US, two solutions are being considered. The first one, certainly less costly, consists in giving America-class amphibious destroyers the capability to operate as small carriers. This is the purpose of the “Lightning” concept, revealed to the public in April 2019, when the USS Wasp was sent into the South China Sea with 10 F-35s onboard. Later that same year, America class ships were loaded with 13 F-35Bs. But the most convincing demonstration came last April, when the America class USS Tripoli operated with 20 F-35s on board.
Following early debates of the Committee on the matter, the National Defense Authorization Act for 2016 directed the Navy to “assess fleet sea-based tactical aviation capability requirements in probable scenarios”, a task then undertaken by the RAND Corporation. In their report, soberly entitled “Future Aircraft Carrier Options”, RAND analysts focused on potential cheaper alternatives to the expensive Gerald Ford class, as part of the replacement of Nimitz class carriers. Several options were considered, from massive carriers of 100,000 tons to a 20,000 tons flattop ship. The latter, according to the report, would cost $2.5bn, and could only accommodate 6 to 10 Short Take-Off/Vertical Landing (STOVL) aircraft.
Assessing this option as if it was thought of as aiming to fully substitute the remaining Nimitz carriers, the analysts obviously concluded that the option was not worth the investment.
The concept made a comeback towards the end of 2020, under the impulse of the former Secretary of Defense, Mark Esper. In spite of its strong unpopularity within the American defense community, the idea thus appeared in the Future Naval Force Study and its Battle Force 2045 plan, before being included for the first time in the 2020 Report to Congress on the Annual Long-Range Plan for Construction of Naval Vessels.
While mentioning the potential procurement of up to six light carriers, this document is not binding, and such ships are still far from becoming a reality for the Navy.
Light aircraft carriers exist across Western navies.
Beyond the US, however, several Western navies already feature light carriers in their fleets. While for the US, the purpose of such ships would be to alleviate the bigger carriers in lower-end missions, nations with smaller militaries and less engagements abroad (if any) can settle for light carriers as a means of sea control, or partake in military operations as part of a coalition.
This has notably been the case of Italy’s 180-meter long Giuseppe Garibaldi carrier, which can load up to 16 aircraft, but not F-35s because take-off strip is too short. The Cavour, Rome’s second flattop, is larger than the Giuseppe Garibaldi, and could still reasonably be regarded as a light carrier —this time, it is big enough to embark F-35Bs. Spain’s now decommissioned Principe de Asturias was comparable in size and capacity to the Giuseppe Garibaldi.
While all three carriers most likely fall into the category of CVLs, Spain’s new carrier, the Juan Carlos I, is an LHD, a hybrid between an amphibious assault ship and an aircraft carrier. Turkey has based its Anadolu carrier on the Juan Carlos I, and the latter was exported to Australia as the Canberra LHD.
While the American Wasp class LHD could easily qualify as a proper aircraft carrier, the Juan Carlos I and Canberra class LHDs are closer to the designs one would think of when discussing light aircraft carriers. The Juan Carlos I, designed by Navantia, can load up to 12 aircraft on its deck.
Light carriers are gaining momentum in Asia.
Aside from Western nations, several Asian countries have invested in such concepts. The first Asian nation to have done so is Thailand, as early as in the 1990s, with its HTMS Chakri Naruebet, based on the Principe de Asturias. The ship is able to carry up to 9 fighter jets. However, since Bangkok decommissioned its AV-8S Harrier jets, the country has no aircraft to load on its carrier, the US being reluctant to export F-35Bs to the country. Such a small carrier can only accommodate vertical landing aircraft, and the JSF happens to be the only one for sale.
Thailand’s difficulties contrast very much with Seoul’s determination to deliver an aircraft carrier to its Navy. South Korea’s CVX program, in which Hyundai competes with DSME, could reportedly result in a mini version of the UK’s HMS Queen Elizabeth, with a weight of about 30,000 tons, a 265-meter flight deck able to host up to 20 F-35Bs, for an estimated $1.8bn. This format would be comparable in size to Italy’s Cavour. Japan, on its side, is modifying two Izumo class multipurpose destroyers into hybrid aircraft carriers, able to host a dozen F-35Bs, a format comparable to the Juan Carlos I.
Are light carriers better suited to UAVs?
While being an attractive option for countries with smaller budgets, integrating a light carrier in a fleet presents several difficulties for their navies. First, the price of such platforms, which while being more affordable than normal-size aircraft carriers unavoidably comes at the expense of numerous other investments. Second, the obligation to purchase F-35Bs, the only STOVL fighter jet on the market, given the reduced size of the deck, which prevents other aircraft from landing. Third, on conversion programs such as Japan’s, the need to adapt the deck to the extreme heat projected by the engines during take-off and landing.
For a country like Turkey, which cannot access the F-35B, another difficulty lies in the need to invest in alternative, sometimes uncertain, solutions. Ankara intends to adapt its future Hürjet light combat aircraft, bringing numerous technical constraints, including the incorporation of a suitable landing gear, and a limited “bring-back capability” aboard the aircraft.
The Bayraktar TB3 drone will be deployed on the Turkish aircraft carrier TCG Anadolu. pic.twitter.com/9Zv9GO5Sif— Ali Özkök (@Ozkok_A) September 21, 2021
For many countries, the perspective of light carriers could ultimately end up matching a different concept: forward operating UAVs. While working to adapt its future LCA to the Anadolu carrier, Turkey is developing the Bayraktar TB3, specifically designed for short-range landing and take-off aboard a carrier. The carrier is currently doing trials in the Sea of Marmara and is expected to enter service by the end of this year. Meanwhile, the Turkish Navy is also reportedly working on a future new ship specially designed to operate a fleet of heavier, jet powered combat drones.
China, while focusing its efforts on massive aircraft carriers - as illustrated by the new Type 003 carrier Fujian leaving her drydock last week - recently unveiled a concept of a 80-meter long and 35-meter wide catamaran serving as a navigating base for drone swarms. Incidentally, a fleet of drones were spotted earlier this year on the Aircraft Carrier Shandong, a first indication of active trials…
In Europe, last September, the Royal Navy has demonstrated its ability to launch drones from HMS Prince of Wales. More recently, in March, the CEO of Baykar Defense indicated that the TB-3 will be compatible with Japan’s Izumo class carries, themselves being upgraded to operate the F-35B….
Additionally, on May 11, General Atomics revealed a short take-off version of its MQ-9B SkyGuardian/SeaGuardian drone, which will likely prompt acquisitions in support of that orientation. Should drone fleets represent the future of light carriers, one could imagine combining them with Boeing’s MQ-25 Stingray aerial refueling drone… bringing carriers equipped with UAVs significant additional operational depth.
This is something that could make a difference in the Asia-Pacific area…And something that has already drawn interest from US allies, Boeing says…