Naval Air: Mini-CV Works


November 22, 2019: The U.S. Navy recently conducted more extensive tests of operating F-35B vertical take-off and landing aircraft from amphibious ships that normally operate helicopters from their flight decks. This test included the navy’s first (of at least three) 45,000 ton LHA amphibious ships. These are the largest amphibs the navy has ever built and can handle up to twenty F-35Bs. For this test the LHA-6 America had 13 F-35Bs on board. Currently, the marines only have 70 of the 340 F-35Bs they will eventually get so obtaining 20 of them for a test was not possible. The two week test at sea was mainly to determine if the LHA and F-35Bs could operate together as a unique type of light aircraft carrier. Operating this intensively from a smaller carrier was something new for the pilots, maintainers and 1,050 crew of the ship.

Everything worked although, as expected, the exercise produced a list of proposed changes and additions to the LHA’s equipment. This was mostly about electronics and communications capabilities. In some ways, the individual F-35Bs have better comm gear than the LHA. The two week exercise did prove that you can operate a large number of F-35Bs from the LHA and carry out a lot of sorties.

An important factor that makes operating F-35Bs from an LHA effective is the use of smart bombs and small air-to-ground guided missiles. The LHA was not designed to haul a lot of munitions for aircraft but the amount of smart bombs and missiles needed to make 13 or 20 F-35Bs effective is not so large that the LHA cannot handle it. This is what made this later-day LPH into an LHA; the combination of smart bombs and more powerful vertical takeoff jets (the F-35B). Normally the LHA would carry six F-35Bs plus 12 V-22 vertical takeoff transports and four heavy-lift helicopter plus seven helicopter gunships and two medium helicopters for search and rescue. Thus an LHA carrying 12-20 F-35Bs could provide more air support for troops ashore than all the attack aircraft on a 1980s (pre-smart bombs) CVN. The navy made the transition to all smart-bombs in the 1990s.

Another advantage of the LHD/LHA is that is the turbine engines, which achieve higher speed and are more economical at lower speeds. Those engines also use the same fuel as the aircraft. The navy is planning to buy as many as eleven LHAs and needs to justify the cost. The effective use of F-35Bs on those LHAs is what the recent LHA/F-35B exercise was all about. The U.S. Navy carrier fleet has shrunk to ten CVN type 100,000 ton carriers, which is often not sufficient to meet all demands for air support at some distant hotspot. This shortage can be made up somewhat by the construction of more LHAs that are capable of carrying up to twenty F-35B fighters.

The design of these mini-carriers began in the 1980s with the eight Wasp class LHDs. The last of these amphibious assault ships (Makin Island, LHD-8) entered service in 2009 and was followed by two more that had some drastic modifications that led them to be designated LHAs because they were a bit larger (45,000 tons) and did not have the internal dock for landing craft. The additional space was devoted to more fuel, weapons storage and aircraft maintenance. The first of these ships (LHA-6) entered service in 2014 and another is undergoing trials while a third is under construction. The navy would like to have at least six of these LHAs but that depends on money being available. More LHAs can be justified now that these ships have demonstrated they can operate like a mini-CV (non-nuclear attack carrier). The last American CV, the 82,000 ton Kitty Hawk, was built in the late 1950s and retired in 2009. Designed to handle up to 85 smaller 1960s era aircraft, Kitty Hawk operated 55-60 aircraft at the end.

The last of the Wasp class LHDs was notable for a number of technical innovations which it did not share with other ships in the class, including gas turbine engines. This LHD, the Makin Island, undertook a two month voyage around the southern tip of South America to its home port in California. This was its first long voyage and the navy found that the gas turbine engines saved some $2 million dollars in fuel costs, versus the steam engines in the other Wasp class ships. The first Wasp class ships began construction in 1985 and the last one was built twenty years later. There was plenty of time to experiment with what such a large amphib could do and led to the successful introduction of the LHAs in 2014.

The 41,000 ton Makin Island looks like an aircraft carrier, and it had 21 transport helicopters, six anti-submarine helicopters and five AV-8B vertical takeoff jet fighter-bombers (to be replaced by F-35Bs) on board. Weapons include two RAM missile launchers and two 20mm Phalanx autocannon for defense against anti-ship missiles. There are three 12.7mm and two 25mm machine-guns for protection against small boats (terrorists). The most potent weapon carried consists of 1,400 marines. The marines are landed by helicopter, while three LCAC hovercraft land vehicles. The ship is operated by 1,100 sailors. Top speed is 37 kilometers an hour and range is 17,600 kilometers.

In addition to the unique (for amphibious ships) gas turbine engine, all the auxiliaries are electric, which requires fewer sailors to operate and maintain. There is an improved fire suppression system and the most advanced command and control systems available. The combination of the gas turbine engines and an Auxiliary Propulsion System are expected to result in fuel savings of over $250 million over the life of the ship.

The first LHA began construction in 2009, at the same time the last Wasp entered service. The LHA lacked the water-level well-deck for landing craft. This made it a helicopter landing platform ship, like the 1960s vintage Iwo Jima-class. The first American LPA was called LPH. The Iwo Jima class were 18,000 ton ships that entered service in 1961 and carried two-thousand troops and twenty-five helicopters. The U.S. retired its last LPHs in the 1990s and U.S. Marine Corps has long sought to get them back.

So, why not just build more baseline Wasp-class ships, which only cost about $800 million each? That is about a third of the cost - and it leads to the natural question of whether the Navy would be better off with three baseline Wasp-class LHDs or even sticking with the Makin Island variant - which only costs about 63 percent what LHA-6 will cost. In other words, three LHDs like the Makin Island can be built for the price of one LHA-6.

The answer is that the air groups of the Marine Expeditionary Units are undergoing a major change - and the ships that carry them need to evolve to properly support them. At the present time, the amphibious ships tend to carry 12 CH-46 troop transport helicopters, 4 AH-1 attack helicopters, 2-4 UH-1 helicopters, 4 CH-53E heavy-lift choppers, and 6-8 multi-role VSTOL aircraft. This is in the process of changing to 12 V-22s, 8 AH-1s, 10 F-35Bs, 4 CH-53Ks, and 4 Navy CH-60 helicopters. In both cases, actual air combat elements (the term for the reinforced squadron deployed on these vessels) may vary depending on the mission. The LHA-6 is being built with these new aircraft, tilt-rotors, and helicopters in mind.

But the lower price of the LHA compared to a CVN is a concept that is being put to the test as the marines get to see if they can get the same level of air support from a smaller carrier. That appears to be the case, especially since smaller numbers of F-35Bs have already been used on amphibious ships and demonstrated their ability to provide adequate air support for ground troops.

Other countries, especially Japan and South Korea, are following these LHA tests closely. South Korea has two 14,500 ton Dokdo class large amphibious ships. These South Korea LPHs (Landing Platform Helicopter) are similar in appearance and operation to the larger American amphibious ships. The LPH flight deck can handle helicopters, as well as vertical takeoff jets like the F-35B. The Koreans deny that the ship will be used with these jets, but the capability is there. The LPH normally carries 720 combat troops and their heavy equipment. Dokdos also carry fifteen aircraft; two V-22 vertical takeoff transports and 13 helicopters. Marado, the second Dokdo, has a redesigned flight deck that can handle two V-22s at once instead of just one. In addition to a more powerful 3-D surveillance radar for tracking aircraft, Marado has the Phalanx anti-missile system. South Korea recently decided to buy some F-35Bs.

South Korea is also planning to build one or more 30,000 ton ships that look like the Japanese DDH (destroyer helicopter carrier) and could handle a dozen F-35Bs. Neighboring Japan has already ordered some F-35Bs so that it can experiment with some of these aircraft aboard the existing Japanese DDHs. Since 2017 Japan has had two 27,000 ton “destroyers” (DDH type ships) that look exactly like an aircraft carrier. These Izumo class ships can carry up to 28 helicopters or up to ten vertical takeoff aircraft. The carriers are armed only with two 20mm Phalanx anti-missile cannon plus launchers with sixteen ESSM missiles for anti-missile defense. The DDH have powerful engines capable of destroyer-like speeds of over fifty-four kilometers an hour. Izumo has considerable cargo capacity, which is intended for moving disaster relief supplies quickly to where they are needed. Apparently, some of these cargo spaces can be converted to carry additional weapons and equipment needed to support F-35Bs. Izumo could carry and operate at least ten F-35B s once modifications are made to the flight deck to deal with the extremely high temperatures the F-35B generates when taking off or landing vertically. When the first DDH entered service in 2015 Japan made no mention of buying F-35Bs or modifying the LPH flight decks to handle very high temperatures. The Izumos already have an elevator (to the hanger deck under the flight deck) powerful enough to carry an F-35B fighter.




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