Anti-submarine warfare is a branch of underwater warfare that uses surface warships, aircraft, or other submarines to find and deter, damage, or destroy enemy submarines. Successful anti-submarine warfare depends on a mix of sensor and weapon technology and experience. Sophisticated sonar equipment for first detecting classifying and tracking the target submarine is a key element of ASW. To destroy submarines, both torpedos and naval mines are used, launched from air and underwater platforms. ASW involves protecting friendly ships; the first attacks on a ship by an underwater vehicle are believed to have been during the American Revolutionary War, using what would now be called a naval mine but what was called a torpedo, though various attempts to build submarines had been made before this. The first self-propelled torpedo was launched from surface craft; the first submarine with a torpedo was Nordenfelt I built in 1884-1885, though it had been proposed earlier. By the outbreak of the Russo-Japanese War all the large navies except the German had acquired submarines.
In 1904 all still defined the submarine as an experimental vessel and did not put it into operational use. There were no means to detect submerged U-boats, attacks on them were limited at first to efforts to damage their periscopes with hammers; the Royal Navy torpedo establishment, HMS Vernon, studied explosive grapnel sweeps. A similar approach featured a string of 70 lb charges on a floating cable, fired electrically. Tried were dropping 18.5 lb hand-thrown guncotton bombs. The Lance Bomb was developed, also. Firing Lyddite shells, or using trench mortars, was tried. Use of nets to ensnare U-boats was examined, as was a destroyer, HMS Starfish, fitted with a spar torpedo. To attack at set depths, aircraft bombs were attached to lanyards. Problems with the lanyards tangling and failing to function led to the development of a chemical pellet trigger as the Type B; these were effective at a distance of around 20 ft. The best concept arose in a 1913 RN Torpedo School report, describing a device intended for countermining, a "dropping mine".
At Admiral John Jellicoe's request, the standard Mark II mine was fitted with a hydrostatic pistol preset for 45 ft firing, to be launched from a stern platform. Weighing 1,150 lb, effective at 100 ft, the "cruiser mine" was a potential hazard to the dropping ship. During the First World War, submarines were a major threat, they operated in North Sea, Black Sea and Mediterranean as well as the North Atlantic. They had been limited to calm and protected waters; the vessels used to combat them were a range of fast surface ships using guns and good luck. They relied on the fact a submarine of the day was on the surface for a range of reasons, such as charging batteries or crossing long distances; the first approach to protect warships was chainlink nets strung from the sides of battleships, as defense against torpedoes. Nets were deployed across the mouth of a harbour or naval base to stop submarines entering or to stop torpedoes of the Whitehead type fired against ships. British warships were fitted with a ram with which to sink submarines, U-15 was thus sunk in August 1914.
RN in June 1915 began operational trials of the Type D depth charge, with a 300 lb charge of TNT and a hydrostatic pistol, firing at either 40 or 80 ft, believed to be effective at a distance of 140 ft. In July 1915, the British Admiralty set up the Board of Invention and Research to evaluate suggestions from the public as well as carrying out their own investigations; some 14,000 suggestions were received about combating submarines. In December 1916, the RN set up its own Anti-Submarine Division but relations with the BIR were poor. After 1917 most ASW work was carried out by ASD. In the U. S. a Naval Consulting Board was set up in 1915 to evaluate ideas. After American entry into the war in 1917, they encouraged work on submarine detection; the U. S. National Research Council, a civilian organization, brought in British and French experts on underwater sound to a meeting with their American counterparts in June 1917. In October 1918, there was a meeting in Paris on "supersonics", a term used for echo-ranging, but the technique was still in research by the end of the war.
The first recorded sinking of a submarine by depth charge was U-68, sunk by Q-ship HMS Farnborough off Kerry, Ireland 22 March 1916. By early 1917, the Royal Navy had developed indicator loops which consisted of long lengths of cables lain on the seabed to detect the magnetic field of submarines as they passed overhead. At this stage they were used in conjunction with controlled mines which could be detonated from a shore station once a'swing' had been detected on the indicator loop galvanometer. Indicator loops used with controlled mining were known as'guard loops'. By July 1917, depth charges had developed to the extent that settings of between 50–200 ft were possible; this design would remain unchanged through
Lockheed Martin F-35 Lightning II
The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, all-weather stealth multirole fighters. The fifth-generation combat aircraft is designed to perform ground-attack and air-superiority missions, it has three main models: the F-35A conventional takeoff and landing variant, the F-35B short take-off and vertical-landing variant, the F-35C carrier-based catapult-assisted take-off but arrested recovery variant. The F-35 descends from the Lockheed Martin X-35, the winning design of the Joint Strike Fighter program, it is built by Lockheed Martin and many subcontractors, including Northrop Grumman, Pratt & Whitney, BAE Systems. The United States principally funds F-35 development, with additional funding from other NATO members and close U. S. allies, including the United Kingdom, Australia, Norway, the Netherlands, Turkey. These funders receive subcontracts to manufacture components for the aircraft. Several other countries are considering ordering, the aircraft; as the largest and most expensive military program, the F-35 is the subject of much scrutiny and criticism in the U.
S. and in other countries. In 2013 and 2014, critics argued that the plane was "plagued with design flaws", with many blaming the procurement process in which Lockheed was allowed "to design and produce the F-35 all at the same time," instead of identifying and fixing "defects before firing up its production line". By 2014, the program was "$163 billion over budget seven years behind schedule". Critics contend that the program's high sunk costs and political momentum make it "too big to kill"; the F-35 first flew on 15 December 2006. In July 2015, the United States Marines declared its first squadron of F-35B fighters ready for deployment. However, the DOD-based durability testing indicated the service life of early-production F-35B aircraft is well under the expected 8,000 flight hours, may be as low as 2,100 flight hours. Lot 9 and aircraft include design changes but service life testing has yet to occur; the U. S. Air Force declared its first squadron of F-35As ready for deployment in August 2016.
The U. S. Navy declared its first F-35Cs ready in February 2019. In 2018, the F-35 made its combat debut with the Israeli Air Force; the U. S. plans to buy 2,663 F-35s, which will provide the bulk of the crewed tactical airpower of the U. S. Air Force and Marine Corps in coming decades. Deliveries of the F-35 for the U. S. military are scheduled until 2037 with a projected service life up to 2070. F-35 development started in 1992 with the origins of the Joint Strike Fighter program and is to culminate in full production in 2018; the X-35 first flew on 24 October 2000 and the F-35A on 15 December 2006. The F-35 was developed to replace most US fighter jets with variants of one design common to all branches of the military, it was developed in co-operation with a number of foreign partners, unlike the F-22 Raptor, intended to be available for export. Three variants were designed: the F-35A, the F-35B, the F-35C. Despite being intended to share most of their parts to reduce costs and improve maintenance logistics, by 2017, the design commonality was only 20%.
The program received considerable criticism for cost overruns during development and for the total projected cost of the program over the lifetime of the jets. By 2017, the program was expected over its lifetime to cost $406.5 billion for acquisition of the jets and $1.1 trillion for operations and maintenance. A number of design deficiencies were alleged, such as carrying a small internal payload, inferior performance to the aircraft being replaced the F-16, the lack of safety in relying on a single engine, flaws were noted such as vulnerability of the fuel tank to fire and the propensity for transonic roll-off; the possible obsolescence of stealth technology was criticized. The single-engined F-35 resembles the larger twin-engined Lockheed Martin F-22 Raptor, drawing design elements from its sibling; the exhaust duct design was inspired by the General Dynamics Model 200, proposed for a 1972 supersonic VTOL fighter requirement for the Sea Control Ship. Although several experimental designs have been developed since the 1960s, such as the unsuccessful Rockwell XFV-12, the F-35B is to be the first operational supersonic STOVL stealth fighter.
Acquisition deputy to the assistant secretary of the Air Force, Lt. Gen. Mark D. "Shack" Shackelford, has said that the F-35 is designed to be America's "premier surface-to-air missile killer and is uniquely equipped for this mission with cutting-edge processing power, synthetic aperture radar integration techniques, advanced target recognition". Lockheed Martin states the F-35 is intended to have close- and long-range air-to-air capability second only to that of the F-22 Raptor. Lockheed Martin has said that the F-35 has the advantage over the F-22 in basing flexibility and "advanced sensors and information fusion". Lockheed Martin has suggested that the F-35 could replace the USAF's F-15C/D fighters in the air-superiority role and the F-15E Strike Eagle in the ground-attack role; some improvements over current-generation fighter aircraft include: Durable, low-maintenance stealth technology, using structural fiber mat instead of the high-maintenance coatings of legacy stealth platforms Integrated avionics and sensor fusion that combine information from off- and on-board sensors to increase the pilot's situational awareness and improve target identification and weapon delivery, to relay information to other command and control nodes High-speed data networking including IEEE 1394b and Fibre Channel (Fibre Ch
Landing Craft Utility
The Landing Craft Utility is a type of boat used by amphibious forces to transport equipment and troops to the shore. They are capable of transporting tracked or wheeled vehicles and troops from amphibious assault ships to beachheads or piers; the Engin de débarquement amphibie rapide landing catamaran or L-CAT, entered service in January 2011. They can carry a main battle tank like other European LCUs but are capable of much higher speeds, up to 30 knots. Germany has two Barbe-class utility landing craft, dating from the mid-1960s, which remain in service under the SEK-M Naval Special Forces' command. Germany is looking to acquire more such crafts. Five Barbe landing crafts were transferred to Greece at the end of the Cold War. India has three Kumbhir class LCU, two Mk III class LCU and four Mk IV class LCU; the first Mk III class LCU was commissioned on 18 July 1986.. Four more MK IV class of LCU are under construction at GRSE. With the launch of the amphibious transport ship HNLMS Rotterdam in 1998 there was a need for LCUs.
The Dutch LCUs are similar to the British LCU Mk.10 with the bridge being set to one side allowing for a roll-on roll-off design. Until 2005 the Netherlands Marine Corps used the LCU Mark I. In 2005 and 2006 the five vessels were modernized to the type Mark II; the vessels have been stretched by 9 meters to decrease their draft, which increased their load carrying capacity by 20 tons and allows them to come closer to shore. In addition they were fitted with a strengthened bow ramp, they can now accommodate the Royal Netherlands Army Leopard 2 A6 main battle tank; because of the lengthening of the Mark II, the Rotterdam can take two LCUs in its dock. The dock of Rotterdam's sister ship, HNLMS Johan de Witt, has the capacity to transport two LCUs, but carries four LCVPs in davits; the Dyugon-class landing craft are operated by the Russian Navy Sweden operates 16 small and fast water jet landing crafts with a displacement of 65 tones. They are armed with one 12,7 mm machine gun but can lay out mines and is equipped with armour for anti submarine warfare.
The vessel type has been exported to the United Arab Emirates. In addition, HSwMS Loke is a larger vessel at a displacement of 305 tones, capable of carrying 150 tones; the ship is armed with two 7,62 mm machine guns. The Armada has been exported to Australia and Turkey; the LCU Mk.9 was built for use on the LPDs Fearless and Intrepid where they were operated from the dock in the rear of the ships. Each ship carried four davit mounted LCVPs; the Mk.9 was to see many changes and upgrades during its service including a move from propeller to jet in many cases. The Mk.9 was capable of traveling as an ocean-going vessel and a number would be converted into a version, affectionately known as the "Black Pig", for use in Norway. The crew heads; the opinion that the successful British amphibious operations during the Falklands War were only possible because of the two LPDs and their landing craft is well documented. In the Falklands War during the Bluff Cove Air Attacks LCU F4 from Fearless was bombed and sunk in Choiseul Sound by an Argentine Air Force A-4B Skyhawk of Grupo 5.
The Mk.9, like the LPDs, served longer than anticipated, providing the backbone of Britain's amphibious assault capabilities. Three Mk.9s, pennant numbers 701, 705, 709, remained in service by 2012. However, by 2014, they had all been withdrawn from service; the LCU Mk.10 class vessels are operated by the Royal Marines. They are intended for use on board the new assault ships Albion and Bulwark and can use the Bay class landing ships. Deliveries of the class started from 1998 and the fleet consists of ten vessels, bearing pennant numbers 1001 to 1010. Both Albion and Bulwark are capable of carrying four LCUs each; these vessels are capable of operating independently for up to 14 days with a range of 600 nautical miles. They are capable of operating worldwide, from Arctic operating areas to tropical operating areas; the Mk.10 differs from the Mk.9 with the bridge being set to the side allowing for a roll-on roll-off design. This increases efficiency over the old Mk.9 as loading of the rear LCUs can take place without the LCUs being launched, the LPD having to dock down to do so, to change over and load up, a problem prior to the Falklands landings.
The LCU Mk.10 has a 7-man crew and can carry up to 120 Marines or alternatively 1 battle tank or 4 lorries. British assault ships carry smaller LCVPs on davits to transport troops and light vehicles. All ten Mk.10s, pennant numbers 1001 to 1010, remain in service as of 2012. The LCU 1466, 1610 and 1627 class vessels are operated by the United States Navy at support commands, they are a self-sustaining craft complete with living accommodations and mess facilities for a crew of thirteen. They have been adapted for many uses including salvage operations, ferry boats for vehicles and passengers, underwater test platforms; each LCU is assigned a non-commissioned-officer-in-charge, either a Chief Petty Officer or Petty Officer First Class in the Boatswain’s Mate, Quartermaster or Operations Specialist rating. These vessels have bow ramps for onload/offload, can be linked bow to stern gate to create a temporary pier-like structure, its welded steel hull provides high durability with deck loads of 800 pounds per square foot.
Arrangement of machinery and equipment has taken into account built-in redundancy in the event of battle damage. The craft features two engine rooms separated by a watertight bulkhead to permit limited operation in the event that one engine room is di
Landing Craft Air Cushion
The Landing Craft Air Cushion is a class of air-cushion vehicle used as landing craft by the United States Navy's Assault Craft Units and the Japan Maritime Self-Defense Force. They transport weapons systems, equipment and personnel of the assault elements of the Marine Air/Ground Task Force both from ship to shore and across the beach. Concept design of the present day LCAC began in the early 1970s with the full-scale Amphibious Assault Landing Craft test vehicle. During the advanced development stage, two prototypes were built. JEFF A was designed and built by Aerojet General in California, with four rotating ducted propellers. JEFF B was built by Bell Aerospace in New Orleans, Louisiana. JEFF B had two ducted rear propellers similar to the proposed SK-10, derived from the previous Bell SK-5 / SR. N5 hovercraft tested in Vietnam; these two craft confirmed the technical feasibility and operational capability that led to the production of LCAC. JEFF B was selected as the design basis for today’s LCAC.
The JEFF A was modified for Arctic use and deployed in Prudhoe Bay to support offshore oil drilling. The first 33 were included in the FY82-86 defense budgets, 15 in FY89, 12 each in FY90, FY91 and FY92, while seven were included in FY93; the first LCAC was delivered to the Navy in 1984 and Initial Operational Capability was achieved in 1986. Approval for full production was granted in 1987. After an initial 15-craft competitive production contract was awarded to each of two companies, Textron Marine & Land Systems of New Orleans, La, Avondale Gulfport Marine, TMLS was selected to build the remaining craft. A total of ninety-one LCAC have now been built; the final craft, LCAC 91, was delivered to the U. S. Navy in 2001. On June 29, 1987, LCAC was granted approval for full production. Forty-eight air-cushion landing craft were authorized and appropriated through FY 89. Lockheed Shipbuilding Company was competitively selected as a second source; the FY 1990 budget request included $219.3 million for nine craft.
The FY 1991 request included full funding for 12 LCACs and advance procurement in support of the FY 1992 program. The remaining 24 were funded in FY92; the LCAC first deployed in 1987 aboard USS Germantown. LCACs are transported in and operate from all the U. S. Navy's amphibious-well deck ships including LHA, LHD, LSD and LPD. Ships capable of carrying the LCAC include the Wasp, Anchorage, Whidbey Island, Harper's Ferry, San Antonio classes. All of the planned 91 craft have been delivered to the Navy. Of these 91 LCACs, seventeen have been disassembled for Government-Furnished Equipment or otherwise terminated for cost reasons, two are held for R&D, 36 are in use on each coast at Little Creek and Camp Pendleton, California. Eight minesweeping kits were acquired in 1994–1995. A service-life extension program to extend service life from 20 to 30 years for the remaining 72 active LCACs was begun in 2000 and is scheduled to be completed by 2018; the craft operates with a crew of five. In addition to beach landing, LCAC provides personnel transport, evacuation support, lane breaching, mine countermeasure operations, Marine and Special Warfare equipment delivery.
The four main engines are all used for all used for main propulsion. The craft can continue to operate, with two engines inoperable, they are interchangeable for redundancy. A transport model can seat 180 equipped troops. Cargo capacity is 1,809 sq ft; the LCAC is capable of carrying a 60-ton payload, including one M-1 Abrams tank, at speeds over 40 knots. Fuel capacity is 5000 gallons; the LCAC uses an average of 1000 gallons per hour. Maneuvering considerations include requiring 500 yards or more to stop and 2000 yards or more turning radius; the bow ramp is 28.8 ft wide. Noise and dust levels are high with this craft. If disabled the craft is difficult to tow. In recent years spray suppression has been added to the craft's skirt to reduce interference with driver's vision; the LCAC is a dramatic innovation in modern amphibious warfare technology. It provides the capability to launch amphibious assaults from points over the horizon from up to 50 nautical miles offshore, thereby decreasing risk to ships and personnel and generating greater uncertainty in the enemy's mind as to the location and timing of an assault, thereby maximizing its prospects of success.
The LCAC propulsion system makes it less susceptible to mines than vehicles. Due to its tremendous over-the-beach capability, the LCAC can access more than 80% of the world's coastlines. Landing craft had a top speed of eight knots and could cross only 17% of the world's beach area. Assaults were made from a few miles off-shore, its high speed complements a joint assault with helicopters, so personnel and equipment can be unloaded beyond the beach in secure landing areas. For 20 years, helicopters have provided the partial capability to launch OTH amphibious assaults. Now, with LCAC, landing craft complement helos in speed, tactical surprise and without exposing ships to enemy fire; the similarities between a Navy LCAC and an airplane are substantial. The craftmaster sits in command module with a headset radio on, he talks to air traffic control which for LCAC's is well-deck control located near a ship's sterngate. The ride feels like a plane in high turbulence; the craftmaster steers with a yoke, his feet are on rudder controls.
The LCAC is similar to a helicopter. Operating the LCAC demands unique perceptual
Bell UH-1Y Venom
The Bell UH-1Y Venom is a twin-engine, medium-sized utility helicopter, built by Bell Helicopter under the H-1 upgrade program of the United States Marine Corps. One of the latest members of the numerous Huey family, the UH-1Y is called "Yankee", based on the NATO phonetic alphabet pronunciation of its variant letter; the UH-1Y was to have been remanufactured from UH-1Ns, but in 2005, it was approved for the aircraft to be built as new. After entering service in 2008, the UH-1Y replaced the USMC's aging fleet of UH-1N Twin Huey light utility helicopters, first introduced in the early 1970s, it is in full-rate production, with deliveries to the Marines to be completed in late 2018. In 1996, the United States Marine Corps launched the H-1 upgrade program by signing a contract with Bell Helicopter for upgrading 100 UH-1Ns into UH-1Ys and upgrading 180 AH-1Ws into AH-1Zs; the H-1 program created modernized attack and utility helicopters with considerable design commonality to reduce operating costs.
The UH-1Y and AH-1Z share a common tailboom, rotor system, avionics architecture, software and displays for over 84% identical components. Over the years new avionics and radios, in addition to modern door guns and safety upgrades, have increased the UH-1N's empty weight. With a maximum speed of 100 knots and an inability to lift much more than its own crew and ammunition, the UH-1N, while useful, is limited in its utility; the Y-model upgrades pilot avionics to a glass cockpit, adds further safety modifications and provides the UH-1 with a modern FLIR system. However, the biggest improvement is an increase in engine power. By replacing the engines and the two-bladed rotor system with four composite blades, the Y-model will return the Huey to the utility role for which it was designed; the UH-1Y was to have been remanufactured from UH-1N airframes, but in April 2005 approval was granted to build them as new helicopters. The Y-model updates an airframe, central to Marine Corps aviation in Iraq.
The Huey has many mission requirements including command and control, reconnaissance, troop transport, medical evacuation and close air support. Detachments of two to four Hueys have been deployed with detachments of four to eight Cobras; the forward-mounted weaponry of the Cobra combined with the door guns of the Huey provides a 240° field of fire. Bell delivered two UH-1Ys to the U. S. Marine Corps in February 2008 and full-rate production was begun in September 2009; the Marine Corps plans to buy 160 Y-models to replace their inventory of N-models. The UH-1Y variant modernizes the UH-1 design, its most noticeable upgrade over previous variants is a four-blade, all-composite rotor system designed to withstand up to 23 mm rounds. A 21-inch fuselage extension just forward of the main door has been added for more capacity; the UH-1Y features upgraded engines and transmissions, a digital cockpit with flat panel multifunctional displays, an 84% parts commonality with the AH-1Z. Compared to the UH-1N, the Y-model has an increased payload 50% greater range, a reduction in vibration, higher cruise speed.
The UH-1Y and AH-1Z completed their developmental testing in early 2006. During the first quarter of 2006 the UH-1Ys were transferred to the Operational Test Unit at NAS Patuxent River, where they began operational evaluation testing. In February 2008, the UH-1Y and AH-1Z began the final portion of OPEVAL testing. On 8 August 2008, the Marine Corps certified the UH-1Y as operationally capable and it was deployed for the first time in January 2009 as part of the aviation combat element of the 13th Marine Expeditionary Unit; the UH-1N Twin Huey was retired by the Marines in August 2014, making the UH-1Y the Marine Corps' standard utility helicopter. On 11 October 2017, the Defense Security Cooperation Agency notified the United States Congress of the potential sale of 12 UH-1Ys and related systems and support to the Czech Republic for a cost of US$575m. United StatesUnited States Marine CorpsHMLA-167 HMLA-169 HMLA-267 HMLA-269 HMLA-367 HMLA-369 HMLA-469 HMLA-773 HMLAT-303 Data from Bell UH-1Y guide, International Directory of Civil AircraftGeneral characteristics Crew: one or two pilots, plus crew chief, other crew members as mission requires Capacity: 6,660 lb including up to ten crashworthy passenger seats, six litters or equivalent cargo Length: 58 ft 4 in Rotor diameter: 48 ft 10 in Height: 14 ft 7 in Disc area: 1,808 ft² Empty weight: 11,840 lb Useful load: 6,660 lb Max.
Takeoff weight: 18,500 lb Powerplant: 2 × General Electric T700-GE-401C turboshaft, 1,828 shp for 2.5 min.
Amphibious assault ship
An amphibious assault ship is a type of amphibious warfare ship employed to land and support ground forces on enemy territory by an amphibious assault. The design evolved from aircraft carriers converted for use as helicopter carriers. Modern ships support amphibious landing craft, with most designs including a well deck. Coming full circle, some amphibious assault ships support V/STOL fixed-wing aircraft, now having a secondary role as aircraft carriers; the role of the amphibious assault ship is fundamentally different from that of a standard aircraft carrier: its aviation facilities have the primary role of hosting helicopters to support forces ashore rather than to support strike aircraft. However, some are capable of serving in the sea-control role, embarking aircraft like Harrier fighters for combat air patrol and helicopters for anti-submarine warfare or operating as a safe base for large numbers of STOVL fighters conducting air support for an expeditionary unit ashore. Most of these ships can carry or support landing craft, such as air-cushioned landing craft or LCUs.
The largest fleet of these types is operated by the United States Navy, including the Wasp class dating back to 1989 and the similar America-class ships that debuted in 2014. Amphibious assault ships are operated by the French Navy, the Italian Navy, the Republic of Korea Navy, the Royal Australian Navy, the Brazilian Navy, the Spanish Navy; the term amphibious assault ship is used interchangeably with other ship classifications. It applies to all large-deck amphibious ships such as the Landing Platform Helicopter, Landing Helicopter Assault, Landing Helicopter Dock. In the Pacific theatre of World War II, escort carriers would escort the landing ships and troop carriers during the island-hopping campaign. In this role, they would provide air cover for the troopships as well as fly the first wave of attacks on the beach fortifications in amphibious landing operations. On occasion, they would escort the large carriers, serving as emergency airstrips and providing fighter cover for their larger sisters while these were busy readying or refuelling their own planes.
In addition, they would transport aircraft and spare parts from the US to the remote island airstrips. Despite all the progress, seen during World War II, there were still fundamental limitations in the types of coastline that were suitable for assault. Beaches had to be free of obstacles, have the right tidal conditions and the correct slope. However, the development of the helicopter fundamentally changed the equation; the first use of helicopters in an amphibious assault came during the invasion of Egypt during the Suez War in 1956. In this engagement, two British light fleet carriers and Theseus, were converted to perform a battalion-size airborne assault with helicopters; the techniques were developed further by American forces during the Vietnam War and refined during training exercises. The modern amphibious assault can take place at any point of the coast, making defending against them difficult. Most early amphibious assault ships were converted from small aircraft carriers; as well as the two Colossus-class light aircraft carriers converted for use in the Suez War, the Royal Navy converted the Centaur-class carriers Albion and Bulwark into "commando carriers" during the 1950s.
Their sister ship HMS Hermes was converted to a commando carrier in the early 1970s, but was restored to aircraft carrier operations before the end of the 1970s. The United States Navy used three Essex-class aircraft carriers. Amphibious assault craft were constructed for the role; the United States Navy constructed the Tarawa class of five Landing Helicopter Assault ships, which began to enter service from the late 1970s, the Wasp class of eight Landing Helicopter Dock ships, the first of, commissioned in 1989. The United States Navy is designing a new class of assault ships: the first America-class ship entered service in October 2014; the first British ship to be constructed for the amphibious assault role was HMS Ocean, commissioned into the Royal Navy in 1998. Other nations have built amphibious assault ships. Most modern amphibious assault ships have a well deck, allowing them to launch landing craft in rougher seas than a ship that has to use cranes or a stern ramp; the US Navy hull classification symbols differ among these vessels, depending on, among other things, their facilities for aircraft: a modern Landing Ship Dock has a helicopter deck, a Landing Platform Dock has a hangar, a Landing Helicopter Dock or Landing Helicopter Assault has a full-length flight deck with internal aviation facilities for both rotary and fixed wing craft below deck.
Due to their aircraft carrier heritage, all amphibious assault ships resemble aircraft carriers in design. The flight deck is used to operate attack and utility helicopters for landing troops and supplies and on some ship types launch and recover Harrier Jump Jets to provide air support to landing operations. STOL aircraft such as the OV-10 were sometimes deployed on and were able to perform short take-offs and landings on large-deck amphibiou
Chairman of the Joint Chiefs of Staff
The Chairman of the Joint Chiefs of Staff is, by U. S. law, the highest-ranking and senior-most military officer in the United States Armed Forces and is the principal military advisor to the President, the National Security Council, the Homeland Security Council, the Secretary of Defense. While the Chairman of the Joint Chiefs of Staff outranks all other commissioned officers, they are prohibited by law from having operational command authority over the armed forces; the Chairman convenes the meetings and coordinates the efforts of the Joint Chiefs of Staff, an advisory body within the Department of Defense comprising the Chairman, the Vice Chairman of the Joint Chiefs of Staff, the Chief of Staff of the Army, the Chief of Naval Operations, the Chief of Staff of the Air Force, the Commandant of the Marine Corps, the Chief of the National Guard Bureau. The post of a statutory and permanent Joint Chiefs of Staff chair was created by the 1949 amendments to the National Security Act of 1947; the 1986 Goldwater-Nichols Act elevated the Chairman from the first among equals to becoming the "principal military advisor" to the President and the Secretary of Defense.
The Joint Staff, managed by the Director of the Joint Staff and consisting of military personnel from all the services, assists the Chairman in fulfilling his duties to the President and Secretary of Defense, functions as a conduit and collector of information between the Chairman and the combatant commanders. The National Military Command Center is part of the Joint Staff operations directorate. Although the office of Chairman of the Joint Chiefs of Staff is considered important and prestigious, neither the Chairman, the Vice Chairman, nor the Joint Chiefs of Staff as a body has any command authority over combatant forces; the Goldwater-Nichols Act places the chain of command from the President to the Secretary of Defense directly to the commanders of the Unified Combatant Commands. However the services chiefs do have authority over personnel assignments and oversight over resources and personnel allocated to the combatant commands within their respective services; the Chairman may transmit communications to the combatant commanders from the President and Secretary of Defense as well as allocate additional funding to the combatant commanders if necessary.
The Chairman performs all other functions prescribed under 10 U. S. C. § 153 or allocates those duties and responsibilities to other officers in the joint staff under his or her name. The principal deputy to the Chairman is the Vice Chairman of the Joint Chiefs of Staff, another four-star general or admiral, who among many duties chairs the Joint Requirements Oversight Council; the Chairman of the Joint Chiefs of Staff is assisted by the Joint Staff, led by the Director of the Joint Staff, a three-star general or admiral. The Joint Staff is an organization composed of equal numbers of officers contributed by the Army, Marine Corps and Air Force, who have been assigned to assist the Chairman with the unified strategic direction and integration of the combatant land and air forces; the National Military Command Center is part of the Joint Staff operations directorate. The Chairman of the Joint Chiefs of Staff is advised on enlisted personnel matters by the Senior Enlisted Advisor to the Chairman, who serves as a communication conduit between the Chairman and the senior enlisted advisors of the combatant commands.
Fleet Admiral William D. Leahy, USN, served as the Chief of Staff to the Commander in Chief from 20 July 1942 to 21 March 1949, he presided over meetings of what was called the Joint Chiefs of Staff, Leahy's office was the precursor to the post of Chairman of the Joint Chiefs of Staff, created in 1942. The Chairman is nominated by the President for appointment and must be confirmed via majority vote by the Senate; the Chairman and Vice Chairman may not be members of the same armed force service branch. However, the President may waive that restriction for a limited period of time in order to provide for the orderly transition of officers appointed to serve in those positions; the Chairman serves a two-year term of office at the pleasure of the President, but can be reappointed to serve two additional terms for a total of six years, as long as the Chairman has not served a term as Vice Chairman, in which case the Chairman would be limited to serving up to two terms. However, in a time of war or national emergency, there is no limit to how many times an officer can be reappointed to serve as Chairman.
The Chairman has served two terms. By statute, the Chairman is appointed as a four-star general or admiral while holding office and assumes office on October 1 of odd-numbered years. Although the first Chairman of the Joint Chiefs of Staff, Omar Bradley, was awarded a fifth star, the CJCS does not receive one by right, Bradley's award was so that his subordinate, General of the Army Douglas MacArthur, would not outrank him. In the 1990s, there were proposals in Department of Defense academic circles to bestow on the office of Chairman of the Joint Chiefs of Staff a five-star rank. According to the 2017 Military Pay Table, basic pay for flag officers is limited by Level II of the Executive Schedule, $15,583.20 per month. This includes officers serving as Chairman or Vice Chairman of the Joint Chiefs of Staff, Chief of Staff of the Army, Chief of Naval Operations, Chief of Staff of the Air Force, Commandant of the Marine Corps, C