The Japanese government’s December announcement that the country’s two helicopter-carrying destroyers Izumo (DDH-183) and Kaga (DDH-184) would be modified to carry F-35B Lightning II fighter-bombers shows the potential impact of the short-takeoff/vertical-landing (STOVL) attack aircraft. The Japan Maritime Self-Defense Force (JMSDF) long has desired small carriers with fixed-wing aircraft to defend the country’s seaborne trade, but until now Japanese governments have resisted building them for fear of political and diplomatic repercussions throughout Asia. Prime Minister Shinzo Abe has argued for decades that Japan must become a “normal country” with a normal capacity for self-defense. The argument has become more acceptable internationally in the face of accelerating Chinese and North Korean military growth.
Japan justified initial construction of these large aircraft-carrying “destroyers” as protection for its seaborne trade because land-based antisubmarine aircraft could not provide the range—out to 1,000 miles—particularly helicopters armed with antiship missiles. At 19,500 long tons (empty), the two Japanese ships are larger than the decommissioned British Invincible-class light carriers, and their hangars seem to have been designed more efficiently. Depending on how much deck stowage is used, they ought to accommodate between 10 and 20 F-35Bs.
China is the main prospective threat to Japanese shipping. The People’s Liberation Army Navy owns a substantial antiship air force of both long-range bombers (currently the Chinese Xian H-6, a license-built copy of the Soviet-era Tu-16 Badger) and high-performance fighter-bombers (the domestically designed JH-7). Estimates put Chinese naval air strength around 36 H-6s and 120 JH-7s, plus many short-range aircraft. Not only the U.S. Navy but also the JMSDF (and South Korean forces) would have to take the air threat seriously. Ship-launched fighters must be a part of defense against such aircraft or any hope of defending merchant shipping at any great distance is gone. The only alternative would be to destroy the Chinese antiship aircraft at their bases, but that would be unacceptable politically until after a war has started and the damage is done.
The two Japanese ships are not remotely equivalent to large U.S. carriers—or even America-class LHAs. They can accommodate many fewer aircraft, and the STOVL performance required for the Lockheed Martin F-35B limits its range and payload capacity compared to the catapult-launched F-35C or the Boeing Super Hornet (F/A-18E/F). Japan owns four Boeing E-767 airborne early warning (AEW) aircraft, but the ships will not be capable of launching organic AEW planes such as the E-2 Hawkeye. (Boeing has promoted an EV-22 AEW-variant of the Osprey but has not developed it to date.) Overall, the smaller the carrier, the higher the price per airplane supported, in terms of tons and ship construction and operating costs.
Despite their limits, these Japanese carriers will afford important sea-based air power. A carrier shortens the distance between air support and troops in a fight on shore. The unpredictable mobility of carriers greatly complicates an enemy’s air-defense problem. And carrier aircraft can operate not only where but also when land-based ones cannot, thanks to a ship’s ability to avoid weather problems. (NATO accomplished this in the Adriatic during the war against Serbia in the 1990s.)
The great question is whether Japan will go on to build larger carriers if the decision to modify the DDHs causes only limited problems. Political opposition to the Japanese project is connected with the potential power-projection capability rather than with shipping protection.
STOVL aircraft have made it possible for countries that cannot possibly afford big carriers to obtain a degree of carrier capability. The subsonic AV-8B Harrier is the most common, serving with Italian, Spanish, and U.S. forces; Thailand has retired its considerably less capable AV-8S version. Navies currently operating the AV-8B have no future alternative other than the F-35B, because it is the sole STOVL fighter/attack airplane currently or prospectively in production. A Soviet-era supersonic very-short-takeoff fighter project (the Yak-141/41) died with the collapse of the Soviet Union, and though Russia announced in 2017 that the Yakovlev Design Bureau would develop a new one, no further information has been forthcoming. Russia and India use conventional aircraft flying from “ski-jump” ramps, which limits aircraft payload. The Chinese have adopted ski-jumps for their first two carriers but supposedly will shift to catapults and arresting gear for future ships.
Spain’s Juan Carlos I, the “strategic projection vessel,” is by far the largest Harrier carrier at about 27,000 long tons. Australia’s Canberra-class and Turkey’s planned Anadolu (to be license-built) are based on the same design. Neither country currently operates STOVL aircraft, but Turkey plans to order F-35Bs for naval use. Australia has purchased the F-35A, but dropped plans to buy the F-35B for the Canberras in 2015 after it was estimated that adapting the ships for F-35Bs would cost more than $4.4 billion—a startlingly high figure (the initial purchase of both ships cost around $3 billion total), which may reflect lobbying against the idea by the Royal Australian Air Force rather than actual cost estimates. Italy has F-35Bs on order for the 27,000-ton carrier Cavour.
Probably the most interesting near-term question is whether South Korea will buy F-35Bs to equip its two- or three-ship Dokdo-class helicopter amphibious ships (LPHs). One is in service and one under construction, with a currently unfunded third not yet laid down. They are relatively small (14,500 tons), but there has been speculation about equipping the third with a ski jump and operating F-35Bs from it.
The Royal Navy expects to use F-35Bs on its two full-size carriers (HMS Queen Elizabeth and the under-construction Prince of Wales). The United Kingdom is an outlier among F-35B users—the 64,000-long-ton carriers certainly are large enough to operate conventional aircraft. Proponents of a “cat-and-trap” option argued, moreover, that a conventional carrier could cross-deck with allied navies; as it is, the British F-35s only will be able to do so with the U.S. Marine Corps. The choice was roundly criticized in the British press, given that the STOVL version of the F-35 did not satisfy stated requirements. For its part, the British government argued that adopting the U.S. electromagnetic catapult and arresting gear would have imposed an unacceptable construction delay. Gross delays in aircraft acquisition have made that argument less persuasive.
The gas-turbine-powered British carriers certainly would have needed considerably more generating capacity, which had not been designed in, to operate electromagnetic catapults. Nor could the designers have fallen back on steam-catapult technology, because the ships could not have generated enough steam. Cynics might note that the F-35B uses a Rolls-Royce (i.e., British) engine and that the British order may have saved the program from cancellation over the high unit-price of the aircraft. Because there is no follow-on to the Harrier, anything keeping the F-35B alive also would keep carrier aviation alive in navies that cannot buy large conventional carriers.
The F-35B may appeal to other navies that operate or want medium-size carriers—including India and Brazil—but it is not clear the airplane is affordable in any quantity. The F-35B is considerably larger and much heavier than the AV-8B, at about twice the takeoff weight—but with about twice the payload. For that price the operator gets a supersonic airplane with much greater range and a more sophisticated weapon system (though that may not be exportable to many potential customers). Critics of the F-35B generally compare it to the conventional take-off versions of the airplane, but comparison with the AV-8B shows enormous superiority.
The F-35B could alter considerably the calculus for many nations when it comes to aircraft carriers. It looks as if Japan is merely the first to implement the new thinking.
