Here’s an article, from the monthly magsazine “Gunji Kenkyu” (Japan Military Review), September 2011 Issue, on the 22DDH helicopter destroyers under construction. Thanks to an unnamed JSW pal for the article and translation.
For ordinary people, except military “mania” (fans/afficianados), flat-topped carrier-style ships are all regarded as “aircraft carriers.” In this regard, the mass media and leftist parties always shoot a questioning glance, saying “This is an aircraft carrier; this is a sign of a military expansion,” every time the JMSDF builds a new flat-topped escort warship.
However, even if it is not flat-topped, the JMSDF Haruna-type escort ship (DDH), which uses one third of the entire length of a ship for a flying-off the deck, is also a carrier (helicopter carrier).
The first flat-top of the JMSDF was Osumi, which was built in 1998. This flat-top ship was originally built as a transport ship, and it was not even an escort ship (destroyer). One third of the flight deck is used for the taking-off and landing of helicopters, but the flight deck is not strong enough to operate a STOVL (Short Take-off and Vertical Landing). However, the size of the ship was equivalent to Chakri Naruebet of the Thai navy.
After Osumi, two Hyuga-class escort ships (16DDH) were built. Their entire length and displacement were about the same size as the Principe de Asturias of Spain, and had full-scale hangers and elevators in the vessels. There was no problem to operate STOVL fighter jets with this capacity and, therefore, it was up to the JMSDF if they would like to use them as helicopter carriers or not.
At present, it is said that the JMSDF has no plan to use other aircraft besides helicopters on the Hyuga-class escort ships, but these ships can carry about twelve F-35B class airplanes, if the JMSDF wishes. There are four spots for taking-off and landing and a space between each spot is widely taken. Of course, it is a different issue whether this ship can load aircraft or properly operate them on this ship.
High-temperature exhaust would most likely become the biggest obstacle when a jet STOVL aircraft is landing and taking off the helicopter deck. If used only once or twice for emergency landings and taking-offs, there will be no major problems. However, the deck areas need to be thermally protected if steady operations are required. Japan has knowledge about the process of operation of STOVL ships, but is deficit in actual know-how.
Currently a new 22DDH is under construction. It is 19,500-ton class DDH with an estimated displacement of 24,000 tons, which is close to Hyuga; and its total ship length, 248 meters, is longer than Hyuga. Whatever the explanation of the JMSDF is, this ship actually is a “carrier” as Japan’s neighboring countries view it. According to the estimation of the JMSDF, the number of helicopters on board the carrier is said to be less than ten. The JMSDF might be estimating conservatively for operation and budget reasons.
By the way, only STOVL Harrier/AV-8B can be used as aircraft for landing and taking off the carrier, after Yak-38 retired. Sea Harriers also have retired since 2006.
If, hypothetically speaking, the JMSDF decides to load STOVL on 22DDH, the aircraft will be, of course, the Joint Strike Fighter STOVL, F-35B, which is currently under development, rather than the old fighter jet, AV-8B. However, it is rumored that the development of F-35Bs has proceeded with difficulty, and the service date of F-35Bs has been postponed. In February last year, a U.S. major general in charge of development was discharged. At present, the F-35s are expected to be put in commission in the Marines after 2018.
Maybe because the British navy did not like a delay in the plan, they cancelled the plan to load STOVL-type Lightning II aircraft on the next carrier, a Queen Elizabeth class warship; but instead announced they would load F-35Cs, which is the same type as an US carrier-borne aircraft, in October 2010. In other words, the British navy is planning to build two Queen Elizabeth class carriers not as STVOL carrier ships, but as conventional carriers (CTOL carriers). They made a policy change.
Queen Elizabeth class carriers use the Integrated Full Electric Propulsion (IFEP) with gas turbines and diesel engines, so their catapult system is not using steam but electromagnetic power. It will be more likely that the carriers will load the Electro Magnetic Aircraft Launching System (EMALS), which the U.S. Navy plans to install on USS GERALD R. FORD class carriers, in a set, with the Lightning II aircraft.
However, the EMALS development is said to be dragging. Even though the British navy once decided to stay away from F-35Bs, they seem to be getting into another difficulty. Some people talk about the possibility of the UK using their self-developed electric catapult, but it is unknown if it can complete the development only by itself. Even the U.S. is having difficulties in the development of the electric catapult.
Ships like the Queen Elizabeth class carriers would be fine with the space to operate even CTOL aircraft, but abovementioned STOVL carriers can only carry STOVL aircraft (and helicopters). If the development of F-35B fails, there is no aircraft that can be loaded on STOVL carriers. STOVL carriers are sharing their lot with F-35Bs.
At the moment, the only country that can develop supersonic STOVL fighters is the U.S., but even the U.S. has to bring the UK and many other countries as development partners, because the U.S. cannot bear the cost by itself. If the U.S. failed in the development on F-35Bs, or gave up on the development plans due to an excess in spending, there is no other country that would be able to replace the U.S.
The application and usefulness of STOVL carriers are always dependant on whether a single type of aircraft can be prepared to be operated on board the carriers. This is actually the weakest point of STOVL carriers regardless the designs of the carriers.
A contributor and editor at the blog War Is Boring, Kyle Mizokami started Japan Security Watch in 2010 to further understand Japan's defenses and security policy.
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