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Armenian language	Sample texts	Sample texts The following texts are the translations of the Article 1 of UDHR: +EnglishEastern ArmenianTransliterationWestern ArmenianTransliterationAll human beings are born free and equal in dignity and rights. They are endowed with reason and conscience and should act towards one another in a spirit of brotherhood.Բոլոր մարդիկ ծնվում են ազատ ու հավասար` իրենց արժանապատվությամբ և իրավունքներով: Նրանք օժտված են բանականությամբ ու խղճով, և պարտավոր են միմյանց նկատմամբ վարվել եղբայրության ոգով:Bolor mardik c'nvowm en azat ow havasar' irenc arjhanapatvowt'yamb ew iravownqnerov: Nranq o'jhtvac' en banakanowt'yamb ow xghtwov, ew partavor en mimyanc nkatmamb varvel eghbayrowt'yan ogov:Բոլոր մարդիկ կը ծնուին ազատ եւ հաւասար իրենց արժանապատուութեամբ եւ իրաւունքներով: Իրենք օժտուած են բանականութեամբ ու խիղճով, եւ պարտաւորուած են միմեանց հանդէպ եղբայրութեան ոգիով վարուիլ:Polor martig gy' dz'nowin azad ew hawasar irenc arjhanabadowowt'eamp ew irawownqnerov. Irenq o'jhtowadz' en panaganowt'eamp ow xightwov, ew bardaworowadz' en mimeanc hante'b eghpayrowt'ean oqiov varowil.
Armenian language	See also	See also Armenian PowerSpell, electronic text corrector Armenian Sign Language Auguste Carrière Classical Armenian orthography European Charter for Regional or Minority Languages Languages of Armenia Language families and languages List of Indo-European languages
Armenian language	Notes	Notes
Armenian language	Footnotes	Footnotes
Armenian language	References	References
Armenian language	Further reading	Further reading (PhD Thesis)
Armenian language	External links	External links Haylib - A free library of courses, books, videos and other resources to help you learn Armenian Armenian PowerSpell ARMENIA AND IRAN iv. History, discussion, and the presentation of Iranian influences in Armenian Language over the millennia Nayiri.com (Library of Armenian dictionaries) dictionaries.arnet.am Collection of Armenian XDXF and Stardict dictionaries Grabar (Brief introduction to Classical Armenian also known as Grabar) բառարան.հայ – Armenian dictionary Category:Articles containing video clips Category:Indo-European languages Category:Languages attested from the 5th century Category:Languages of Armenia Category:Languages of Azerbaijan Category:Languages of Cyprus Category:Languages of Georgia (country) Category:Languages of Iran Category:Languages of Kazakhstan Category:Languages of Kurdistan Category:Languages of Lebanon Category:Languages of Russia Category:Languages of the Caucasus Category:Languages of Turkey Category:Subject–object–verb languages Category:Syllable-timed languages
Armenian language	Table of Content	Short description, History, Classification and origins, Early contacts, Graeco-Armenian hypothesis, Greco-Armeno-Aryan hypothesis, Evolution, Geographic distribution, Status and usage, Phonology, Stress, Vowels, Consonants, Morphology, Nouns, Verbs, Dialects, Orthography, Vocabulary, Indo-European cognates, Sample texts, See also, Notes, Footnotes, References, Further reading, External links
Additive synthesis	Short description	Additive synthesis is a sound synthesis technique that creates timbre by adding sine waves together. The timbre of musical instruments can be considered in the light of Fourier theory to consist of multiple harmonic or inharmonic partials or overtones. Each partial is a sine wave of different frequency and amplitude that swells and decays over time due to modulation from an ADSR envelope or low frequency oscillator. Additive synthesis most directly generates sound by adding the output of multiple sine wave generators. Alternative implementations may use pre-computed wavetables or the inverse fast Fourier transform.
Additive synthesis	Explanation	Explanation The sounds that are heard in everyday life are not characterized by a single frequency. Instead, they consist of a sum of pure sine frequencies, each one at a different amplitude. When humans hear these frequencies simultaneously, we can recognize the sound. This is true for both "non-musical" sounds (e.g. water splashing, leaves rustling, etc.) and for "musical sounds" (e.g. a piano note, a bird's tweet, etc.). This set of parameters (frequencies, their relative amplitudes, and how the relative amplitudes change over time) are encapsulated by the timbre of the sound. Fourier analysis is the technique that is used to determine these exact timbre parameters from an overall sound signal; conversely, the resulting set of frequencies and amplitudes is called the Fourier series of the original sound signal. In the case of a musical note, the lowest frequency of its timbre is designated as the sound's fundamental frequency. For simplicity, we often say that the note is playing at that fundamental frequency (e.g. "middle C is 261.6 Hz"), even though the sound of that note consists of many other frequencies as well. The set of the remaining frequencies is called the overtones (or the harmonics, if their frequencies are integer multiples of the fundamental frequency) of the sound. In other words, the fundamental frequency alone is responsible for the pitch of the note, while the overtones define the timbre of the sound. The overtones of a piano playing middle C will be quite different from the overtones of a violin playing the same note; that's what allows us to differentiate the sounds of the two instruments. There are even subtle differences in timbre between different versions of the same instrument (for example, an upright piano vs. a grand piano). Additive synthesis aims to exploit this property of sound in order to construct timbre from the ground up. By adding together pure frequencies (sine waves) of varying frequencies and amplitudes, we can precisely define the timbre of the sound that we want to create.
Additive synthesis	Definitions	Definitions 250px\|thumb\|right\|Schematic diagram of additive synthesis. The inputs to the oscillators are frequencies and amplitudes . Harmonic additive synthesis is closely related to the concept of a Fourier series which is a way of expressing a periodic function as the sum of sinusoidal functions with frequencies equal to integer multiples of a common fundamental frequency. These sinusoids are called harmonics, overtones, or generally, partials. In general, a Fourier series contains an infinite number of sinusoidal components, with no upper limit to the frequency of the sinusoidal functions and includes a DC component (one with frequency of 0 Hz). Frequencies outside of the human audible range can be omitted in additive synthesis. As a result, only a finite number of sinusoidal terms with frequencies that lie within the audible range are modeled in additive synthesis. A waveform or function is said to be periodic if for all and for some period . The Fourier series of a periodic function is mathematically expressed as: where is the fundamental frequency of the waveform and is equal to the reciprocal of the period, is the amplitude of the th harmonic, is the phase offset of the th harmonic. atan2 is the four-quadrant arctangent function, Being inaudible, the DC component, , and all components with frequencies higher than some finite limit, , are omitted in the following expressions of additive synthesis.
Additive synthesis	Harmonic form	Harmonic form The simplest harmonic additive synthesis can be mathematically expressed as: where is the synthesis output, , , and are the amplitude, frequency, and the phase offset, respectively, of the th harmonic partial of a total of harmonic partials, and is the fundamental frequency of the waveform and the frequency of the musical note.
Additive synthesis	Time-dependent amplitudes	Time-dependent amplitudes 280px Example of harmonic additive synthesis in which each harmonic has a time-dependent amplitude. The fundamental frequency is 440 Hz. noicon\|150px Problems listening to this file? See Media help More generally, the amplitude of each harmonic can be prescribed as a function of time, , in which case the synthesis output is Each envelope should vary slowly relative to the frequency spacing between adjacent sinusoids. The bandwidth of should be significantly less than .
Additive synthesis	Inharmonic form	Inharmonic form Additive synthesis can also produce inharmonic sounds (which are aperiodic waveforms) in which the individual overtones need not have frequencies that are integer multiples of some common fundamental frequency. (online reprint) While many conventional musical instruments have harmonic partials (e.g. an oboe), some have inharmonic partials (e.g. bells). Inharmonic additive synthesis can be described as where is the constant frequency of th partial. 280px Example of inharmonic additive synthesis in which both the amplitude and frequency of each partial are time-dependent. noicon\|150px Problems listening to this file? See Media help
Additive synthesis	Time-dependent frequencies	Time-dependent frequencies In the general case, the instantaneous frequency of a sinusoid is the derivative (with respect to time) of the argument of the sine or cosine function. If this frequency is represented in hertz, rather than in angular frequency form, then this derivative is divided by . This is the case whether the partial is harmonic or inharmonic and whether its frequency is constant or time-varying. In the most general form, the frequency of each non-harmonic partial is a non-negative function of time, , yielding
Additive synthesis	Broader definitions	Broader definitions Additive synthesis more broadly may mean sound synthesis techniques that sum simple elements to create more complex timbres, even when the elements are not sine waves. For example, F. Richard Moore listed additive synthesis as one of the "four basic categories" of sound synthesis alongside subtractive synthesis, nonlinear synthesis, and physical modeling. In this broad sense, pipe organs, which also have pipes producing non-sinusoidal waveforms, can be considered as a variant form of additive synthesizers. Summation of principal components and Walsh functions have also been classified as additive synthesis.
Additive synthesis	Implementation methods	Implementation methods Modern-day implementations of additive synthesis are mainly digital. (See section Discrete-time equations for the underlying discrete-time theory)
Additive synthesis	Oscillator bank synthesis	Oscillator bank synthesis Additive synthesis can be implemented using a bank of sinusoidal oscillators, one for each partial.
Additive synthesis	Wavetable synthesis	Wavetable synthesis In the case of harmonic, quasi-periodic musical tones, wavetable synthesis can be as general as time-varying additive synthesis, but requires less computation during synthesis. As a result, an efficient implementation of time-varying additive synthesis of harmonic tones can be accomplished by use of wavetable synthesis.
Additive synthesis	Group additive synthesis	Group additive synthesis Group additive synthesis is a method to group partials into harmonic groups (having different fundamental frequencies) and synthesize each group separately with wavetable synthesis before mixing the results.
Additive synthesis	Inverse FFT synthesis	Inverse FFT synthesis An inverse fast Fourier transform can be used to efficiently synthesize frequencies that evenly divide the transform period or "frame". By careful consideration of the DFT frequency-domain representation it is also possible to efficiently synthesize sinusoids of arbitrary frequencies using a series of overlapping frames and the inverse fast Fourier transform.
Additive synthesis	Additive analysis/resynthesis	Additive analysis/resynthesis thumb\|350px\|Sinusoidal analysis/synthesis system for Sinusoidal Modeling (based on ) It is possible to analyze the frequency components of a recorded sound giving a "sum of sinusoids" representation. This representation can be re-synthesized using additive synthesis. One method of decomposing a sound into time varying sinusoidal partials is short-time Fourier transform (STFT)-based McAulay-Quatieri Analysis. By modifying the sum of sinusoids representation, timbral alterations can be made prior to resynthesis. For example, a harmonic sound could be restructured to sound inharmonic, and vice versa. Sound hybridisation or "morphing" has been implemented by additive resynthesis. Additive analysis/resynthesis has been employed in a number of techniques including Sinusoidal Modelling, Spectral Modelling Synthesis (SMS), and the Reassigned Bandwidth-Enhanced Additive Sound Model. Software that implements additive analysis/resynthesis includes: SPEAR,SPEAR Sinusoidal Partial Editing Analysis and Resynthesis for Mac OS X, MacOS 9 and Windows LEMUR, LORIS, SMSTools,SMSTools application for Windows ARSS.ARSS: The Analysis & Resynthesis Sound Spectrograph
Additive synthesis	Products	Products New England Digital Synclavier had a resynthesis feature where samples could be analyzed and converted into "timbre frames" which were part of its additive synthesis engine. Technos acxel, launched in 1987, utilized the additive analysis/resynthesis model, in an FFT implementation. Also a vocal synthesizer, Vocaloid have been implemented on the basis of additive analysis/resynthesis: its spectral voice model called Excitation plus Resonances (EpR) model (PDF) (PDF). See "Excitation plus resonances voice model" (p. 51) is extended based on Spectral Modeling Synthesis (SMS), and its diphone concatenative synthesis is processed using spectral peak processing (SPP), "Spectral peak processing" technique similar to modified phase-locked vocoder, "Phase locked vocoder" (an improved phase vocoder for formant processing). Using these techniques, spectral components (formants) consisting of purely harmonic partials can be appropriately transformed into desired form for sound modeling, and sequence of short samples (diphones or phonemes) constituting desired phrase, can be smoothly connected by interpolating matched partials and formant peaks, respectively, in the inserted transition region between different samples. (See also Dynamic timbres)
Additive synthesis	Applications	Applications
Additive synthesis	Musical instruments	Musical instruments Additive synthesis is used in electronic musical instruments. It is the principal sound generation technique used by Eminent organs.
Additive synthesis	Speech synthesis	Speech synthesis In linguistics research, harmonic additive synthesis was used in the 1950s to play back modified and synthetic speech spectrograms. Later, in the early 1980s, listening tests were carried out on synthetic speech stripped of acoustic cues to assess their significance. Time-varying formant frequencies and amplitudes derived by linear predictive coding were synthesized additively as pure tone whistles. This method is called sinewave synthesis. Also the composite sinusoidal modeling (CSM) used on a singing speech synthesis feature on the Yamaha CX5M (1984), is known to use a similar approach which was independently developed during 1966–1979. These methods are characterized by extraction and recomposition of a set of significant spectral peaks corresponding to the several resonance modes occurring in the oral cavity and nasal cavity, in a viewpoint of acoustics. This principle was also utilized on a physical modeling synthesis method, called modal synthesis. (See also companion page)
Additive synthesis	History	History Harmonic analysis was discovered by Joseph Fourier, who published an extensive treatise of his research in the context of heat transfer in 1822. The theory found an early application in prediction of tides. Around 1876, William Thomson (later ennobled as Lord Kelvin) constructed a mechanical tide predictor. It consisted of a harmonic analyzer and a harmonic synthesizer, as they were called already in the 19th century. The analysis of tide measurements was done using James Thomson's integrating machine. The resulting Fourier coefficients were input into the synthesizer, which then used a system of cords and pulleys to generate and sum harmonic sinusoidal partials for prediction of future tides. In 1910, a similar machine was built for the analysis of periodic waveforms of sound. The synthesizer drew a graph of the combination waveform, which was used chiefly for visual validation of the analysis. Georg Ohm applied Fourier's theory to sound in 1843. The line of work was greatly advanced by Hermann von Helmholtz, who published his eight years worth of research in 1863. Helmholtz believed that the psychological perception of tone color is subject to learning, while hearing in the sensory sense is purely physiological. He supported the idea that perception of sound derives from signals from nerve cells of the basilar membrane and that the elastic appendages of these cells are sympathetically vibrated by pure sinusoidal tones of appropriate frequencies. Helmholtz agreed with the finding of Ernst Chladni from 1787 that certain sound sources have inharmonic vibration modes. In Helmholtz's time, electronic amplification was unavailable. For synthesis of tones with harmonic partials, Helmholtz built an electrically excited array of tuning forks and acoustic resonance chambers that allowed adjustment of the amplitudes of the partials. Built at least as early as in 1862, these were in turn refined by Rudolph Koenig, who demonstrated his own setup in 1872. For harmonic synthesis, Koenig also built a large apparatus based on his wave siren. It was pneumatic and utilized cut-out tonewheels, and was criticized for low purity of its partial tones. Also tibia pipes of pipe organs have nearly sinusoidal waveforms and can be combined in the manner of additive synthesis. In 1938, with significant new supporting evidence, it was reported on the pages of Popular Science Monthly that the human vocal cords function like a fire siren to produce a harmonic-rich tone, which is then filtered by the vocal tract to produce different vowel tones. By the time, the additive Hammond organ was already on market. Most early electronic organ makers thought it too expensive to manufacture the plurality of oscillators required by additive organs, and began instead to build subtractive ones. In a 1940 Institute of Radio Engineers meeting, the head field engineer of Hammond elaborated on the company's new Novachord as having a "subtractive system" in contrast to the original Hammond organ in which "the final tones were built up by combining sound waves". Alan Douglas used the qualifiers additive and subtractive to describe different types of electronic organs in a 1948 paper presented to the Royal Musical Association. The contemporary wording additive synthesis and subtractive synthesis can be found in his 1957 book The electrical production of music, in which he categorically lists three methods of forming of musical tone-colours, in sections titled Additive synthesis, Subtractive synthesis, and Other forms of combinations. A typical modern additive synthesizer produces its output as an electrical, analog signal, or as digital audio, such as in the case of software synthesizers, which became popular around year 2000.
Additive synthesis	Timeline	Timeline The following is a timeline of historically and technologically notable analog and digital synthesizers and devices implementing additive synthesis. Research implementation or publication Commercially available Company or institution Synthesizer or synthesis device Description Audio samples 1900 1906 New England Electric Music Company Telharmonium The first polyphonic, touch-sensitive music synthesizer. Implemented sinuosoidal additive synthesis using tonewheels and alternators. Invented by Thaddeus Cahill. no known recordings 1933 1935 Hammond Organ Company Hammond Organ An electronic additive synthesizer that was commercially more successful than Telharmonium. Implemented sinusoidal additive synthesis using tonewheels and magnetic pickups. Invented by Laurens Hammond. 1950 or earlier Haskins Laboratories Pattern Playback A speech synthesis system that controlled amplitudes of harmonic partials by a spectrogram that was either hand-drawn or an analysis result. The partials were generated by a multi-track optical tonewheel. samples 1958 ANS An additive synthesizer that played microtonal spectrogram-like scores using multiple multi-track optical tonewheels. Invented by Evgeny Murzin. A similar instrument that utilized electronic oscillators, the Oscillator Bank, and its input device Spectrogram were realized by Hugh Le Caine in 1959. 1963 MIT An off-line system for digital spectral analysis and resynthesis of the attack and steady-state portions of musical instrument timbres by David Luce. 1964 University of Illinois Harmonic Tone Generator An electronic, harmonic additive synthesis system invented by James Beauchamp. samples (info) 1974 or earlier 1974 RMI Harmonic Synthesizer The first synthesizer product that implemented additive synthesis using digital oscillators. The synthesizer also had a time-varying analog filter. RMI was a subsidiary of Allen Organ Company, which had released the first commercial digital church organ, the Allen Computer Organ, in 1971, using digital technology developed by North American Rockwell. 1 2 3 4 1974 EMS (London) Digital Oscillator Bank A bank of digital oscillators with arbitrary waveforms, individual frequency and amplitude controls, intended for use in analysis-resynthesis with the digital Analysing Filter Bank (AFB) also constructed at EMS. Also known as: DOB. in The New Sound of Music Includes a demonstration of DOB and AFB. 1976 1976 Fairlight Qasar M8 An all-digital synthesizer that used the fast Fourier transform to create samples from interactively drawn amplitude envelopes of harmonics. samples 1977 Bell Labs Digital Synthesizer A real-time, digital additive synthesizer that has been called the first true digital synthesizer. Also known as: Alles Machine, Alice. sample (info) 1979 1979 New England Digital Synclavier II A commercial digital synthesizer that enabled development of timbre over time by smooth cross-fades between waveforms generated by additive synthesis. 1996KawaiK5000A commercial digital synthesizer workstation capable of polyphonic, digital additive synthesis of up to 128 sinusodial waves, as well as combing PCM waves.
Additive synthesis	Discrete-time equations	Discrete-time equations In digital implementations of additive synthesis, discrete-time equations are used in place of the continuous-time synthesis equations. A notational convention for discrete-time signals uses brackets i.e. and the argument can only be integer values. If the continuous-time synthesis output is expected to be sufficiently bandlimited; below half the sampling rate or , it suffices to directly sample the continuous-time expression to get the discrete synthesis equation. The continuous synthesis output can later be reconstructed from the samples using a digital-to-analog converter. The sampling period is . Beginning with (), and sampling at discrete times results in where is the discrete-time varying amplitude envelope is the discrete-time backward difference instantaneous frequency. This is equivalent to where for all and
Additive synthesis	See also	See also Frequency modulation synthesis Subtractive synthesis Speech synthesis Harmonic series (music)
Additive synthesis	References	References
Additive synthesis	External links	External links Digital Keyboards Synergy Category:Sound synthesis types
Additive synthesis	Table of Content	Short description, Explanation, Definitions, Harmonic form, Time-dependent amplitudes, Inharmonic form, Time-dependent frequencies, Broader definitions, Implementation methods, Oscillator bank synthesis, Wavetable synthesis, Group additive synthesis, Inverse FFT synthesis, Additive analysis/resynthesis, Products, Applications, Musical instruments, Speech synthesis, History, Timeline, Discrete-time equations, See also, References, External links
Aircraft carrier	Short description	thumb\|upright=1.35\|Four modern aircraft carriers of various types—, Charles de Gaulle (French Navy), , helicopter carrier —and escort vessels, 2002 thumb\|upright=1.35\|Chinese aircraft carrier Liaoning An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and hangar facilities for supporting, arming, deploying and recovering shipborne aircraft. Typically it is the capital ship of a fleet (known as a carrier battle group), as it allows a naval force to project seaborne air power far from homeland without depending on local airfields for staging aircraft operations. Since their inception in the early 20th century, aircraft carriers have evolved from wooden vessels used to deploy individual tethered reconnaissance balloons, to nuclear-powered supercarriers that carry dozens of fighters, strike aircraft, military helicopters, AEW&Cs and other types of aircraft such as UCAVs. While heavier fixed-wing aircraft such as airlifters, gunships and bombers have been launched from aircraft carriers, these aircraft have not landed on a carrier due to flight deck limitations. The aircraft carrier, along with its onboard aircraft and defensive ancillary weapons, is the largest weapon system ever created. By their tactical prowess, mobility, autonomy and the variety of operational means, aircraft carriers are often the centerpiece of modern naval warfare, and have significant diplomatic influence in deterrence, command of the sea and air supremacy. Since the Second World War, the aircraft carrier has replaced the battleship in the role of flagship of a fleet, and largely transformed naval battles from gunfire to beyond-visual-range air strikes. In addition to tactical aptitudes, it has great strategic advantages in that, by sailing in international waters, it does not need to interfere with any territorial sovereignty and thus does not risk diplomatic complications or conflict escalation due to trespassing, and obviates the need for land use authorizations from third-party countries, reduces the times and transit logistics of aircraft and therefore significantly increases the time of availability on the combat zone. thumb\|right\|upright=1.35\|A selection of aircraft carriers, sorted by length There is no single definition of an "aircraft carrier", and modern navies use several variants of the type. These variants are sometimes categorized as sub-types of aircraft carriers, and sometimes as distinct types of aviation-capable ships. Aircraft carriers may be classified according to the type of aircraft they carry and their operational assignments. Admiral Sir Mark Stanhope, RN, former First Sea Lord (head) of the Royal Navy, has said, "To put it simply, countries that aspire to strategic international influence have aircraft carriers." Henry Kissinger, while United States Secretary of State, also said: "An aircraft carrier is 100,000 tons of diplomacy." As of , there are 50 active aircraft carriers in the world operated by fifteen navies. The United States has 11 large nuclear-powered CATOBAR fleet carriers — each carrying around 80 fighters — the largest in the world, with the total combined deck space over twice that of all other nations combined. In addition, the US Navy has nine amphibious assault ships used primarily as helicopter carriers, although these also each carry up to 20 vertical/short takeoff and landing (V/STOL) jetfighters and are similar in size to medium-sized fleet carriers. China, the United Kingdom and India each currently operate two STOBAR/STOVL aircraft carriers with ski-jump flight decks, with China in the process to commission a third carrier with catapult capabilities, and France and Russia each operate a single aircraft carrier with a capacity of 30 to 60 fighters. Italy operates two light V/STOL carriers, while Spain,Turkey and Iran operate one V/STOL aircraft-carrying assault ship. Helicopter carriers are also operated by Japan (4, two of which are being converted to operate V/STOL fighters), France (3), Australia (2, previously also owned 3 light carriers), Egypt (2), South Korea (2), China (3), Thailand (1), Brazil (1) and Iran (1). Future aircraft carriers are under construction or in planning by China, France, India, Italy, Russia, South Korea, Turkey and the United States.
Aircraft carrier	Types of carriers	Types of carriers thumb\|French aircraft carrier (rear) and US Navy carrier conducting joint operations in the Persian Gulf, each with the CATOBAR configuration
Aircraft carrier	General features	General features Speed is a crucial attribute for aircraft carriers, as they need to be able to be deployed quickly anywhere in the world and have to be fast enough to evade detection and targeting from enemy forces. A high speed also increases the "wind over the deck", boosting the lift available for fixed-wing aircraft to carry fuel and ammunition. To evade nuclear submarines, the carriers should have a speed of more than . Aircraft carriers are among the largest types of warships due to their need for ample deck space. An aircraft carrier must be able to perform increasingly diverse mission sets. Diplomacy, power projection, quick crisis response force, land attack from the sea, sea base for helicopter and amphibious assault forces, anti-surface warfare (ASUW), defensive counter air (DCA), and humanitarian aid & disaster relief (HADR) are some of the missions the aircraft carrier is expected to accomplish. Traditionally an aircraft carrier is supposed to be one ship that can perform at least power projection and sea control missions. An aircraft carrier must be able to efficiently operate an air combat group. This means it should handle fixed-wing jets as well as helicopters. This includes ships designed to support operations of short-takeoff/vertical-landing (STOVL) jets.
Aircraft carrier	Basic types	Basic types Aircraft cruiser Amphibious assault ship and sub-types Anti-submarine warfare carrier Balloon carrier and balloon tenders Escort carrier Fleet carrier Flight deck cruiser Helicopter carrier Light aircraft carrier Seaplane tender and seaplane carriers Utility carrier: This type was mainly used in the US Navy, in the decade after World War 2 to ferry aircraft.USS Guadalcanal (AVG-60/ACV-60/CVE-60/CVU-60), official page at official website https://www.history.navy.mil/ Some of the types listed here are not strictly defined as aircraft carriers by some sources.
Aircraft carrier	By role	By role thumb\|, a United States Navy fleet carrier, also often referred to as a supercarrier, crossing the Atlantic in 2019 A fleet carrier is intended to operate with the main fleet and usually provides an offensive capability. These are the largest carriers capable of fast speeds. By comparison, escort carriers were developed to provide defense for convoys of ships. They were smaller and slower with lower numbers of aircraft carried. Most were built from mercantile hulls or, in the case of merchant aircraft carriers, were bulk cargo ships with a flight deck added on top. Light aircraft carriers were fast enough to operate with the main fleet but of smaller size with reduced aircraft capacity. The Soviet aircraft carrier Admiral Kusnetsov was termed a "heavy aircraft-carrying cruiser". This was primarily a legal construct to avoid the limitations of the Montreux Convention preventing 'aircraft carriers' transiting the Turkish Straits between the Soviet Black Sea bases and the Mediterranean Sea. These ships, while sized in the range of large fleet carriers, were designed to deploy alone or with escorts. In addition to supporting fighter aircraft and helicopters, they provide both strong defensive weaponry and heavy offensive missiles equivalent to a guided-missile cruiser.
Aircraft carrier	By configuration	By configuration thumb\|Aircraft carriers in the STOVL configuration are in service with Italy, Spain, Thailand and the United Kingdom. Aircraft carriers today are usually divided into the following four categories based on the way that aircraft take off and land: Catapult-assisted take-off barrier-arrested recovery (CATOBAR): these carriers generally carry the largest, heaviest, and most heavily armed aircraft, although smaller CATOBAR carriers may have other limitations (weight capacity of aircraft elevator, etc.). All CATOBAR carriers in service today are nuclear-powered, as the last conventionally powered CATOBAR carrier USS Kitty Hawk was decommissioned in 2009. Twelve are in service: ten and one fleet carriers in the United States; and the Charles de Gaulle in France. Short take-off barrier-arrested recovery (STOBAR): these carriers are generally limited to carrying lighter fixed-wing aircraft with more limited payloads. STOBAR carrier air wings, such as the Sukhoi Su-33 and future Mikoyan MiG-29K wings of are often geared primarily towards air superiority and fleet defense roles rather than strike/power projection tasks, which require heavier payloads (bombs and air-to-ground missiles). Five are in service: two in China, two in India, and one in Russia. Short take-off vertical-landing (STOVL): limited to carrying STOVL aircraft. STOVL aircraft, such as the Harrier family and Yakovlev Yak-38 generally have limited payloads, lower performance, and high fuel consumption when compared with conventional fixed-wing aircraft; however, a new generation of STOVL aircraft, currently consisting of the Lockheed Martin F-35B Lightning II, has much improved performance. Fourteen are in service; nine STOVL amphibious assault ships in the US; two carriers each in Italy and the UK; and one STOVL amphibious assault ship in Spain. Helicopter carrier: Helicopter carriers have a similar appearance to other aircraft carriers but operate only helicopters – those that mainly operate helicopters but can also operate fixed-wing aircraft are known as STOVL carriers (see above). Seventeen are in service: four in Japan; three in France; two each in Australia, China, Egypt and South Korea; and one each in Brazil and Thailand. In the past, some conventional carriers were converted and these were called "commando carriers" by the Royal Navy. Some helicopter carriers, but not all, are classified as amphibious assault ships, tasked with landing and supporting ground forces on enemy territory.
Aircraft carrier	By size	By size Fleet carrier Light aircraft carrier Escort carrier
Aircraft carrier	Supercarrier	Supercarrier thumb\|right\|The Royal Navy's HMS Ark Royal in 1939, with Swordfish biplane bombers passing overhead. The British aircraft carrier was involved in the crippling of the German battleship Bismarck in May 1941. The appellation "supercarrier" is not an official designation with any national navy, but a term used predominantly by the media and typically when reporting on larger and more advanced carrier types. It is also used when comparing carriers of various sizes and capabilities, both current and past. It was first used by The New York Times in 1938, in an article about the Royal Navy's , that had a length of , a displacement of 22,000 tons and was designed to carry 72 aircraft. Since then, aircraft carriers have consistently grown in size, both in length and displacement, as well as improved capabilities; in defense, sensors, electronic warfare, propulsion, range, launch and recovery systems, number and types of aircraft carried and number of sorties flown per day.FIREPOWER: THE WEAPONS THE PROFESSIONALS USE – AND HOW. SUPERCARRIERS, #25 Orbis Publishing 1990 Both China (Type 003), and the United Kingdom (Queen Elizabeth class) have carriers undergoing trials or in service with full load displacements between 80,000 to 85,000 tonnes and lengths from which are described as "supercarriers". France is also developing a new aircraft carrier (PANG) which is to have a full load displacement of c. 75,000 tonnes and also be considered a supercarrier. The largest supercarriers in service as of 2024, however, are with the US Navy, with full load displacements in excess 100,000 tons, lengths of over , and capabilities that exceed those of any other class.
Aircraft carrier	Hull type identification symbols	Hull type identification symbols Several systems of identification symbol for aircraft carriers and related types of ship have been used. These include the pennant numbers used by the Royal Navy, Commonwealth countries, and Europe, along with the hull classification symbols used by the US and Canada. + US hull classification symbols for aircraft carriers and related ship types Symbol Designation CV Generic aircraft carrier CVA Attack carrier (up to 1975) CVB Large aircraft carrier (retired 1952) CVAN Nuclear-powered attack carrier CVE Escort carrier CVHA Aircraft carrier, Helicopter Assault (retired) CVHE Aircraft carrier, Helicopter, Escort (retired) CVV Aircraft Carrier (Medium) (proposed) CVL Light aircraft carrier CVN Nuclear-powered aircraft carrier CVS Anti-submarine warfare carrier CVT Training Aircraft Carrier CVU Utility carrier (retired) LHA Landing helicopter assault, a type of amphibious assault ship LHD Landing helicopter dock, a type of amphibious assault ship LPH Landing platform helicopter, a type of amphibious assault ship
Aircraft carrier	History	History
Aircraft carrier	Origins	Origins thumb\|right\|The conducted the world's first naval-launched air raids in 1914. The 1903 advent of the heavier-than-air fixed-wing airplane with the Wright brothers' first flight at Kitty Hawk, North Carolina, was followed on 14 November 1910, by Eugene Burton Ely's first experimental take-off of a Curtiss Pusher airplane from the deck of a United States Navy ship, the cruiser anchored off Norfolk Navy Base in Virginia. Two months later, on 18 January 1911, Ely landed his Curtiss Pusher airplane on a platform on the armored cruiser anchored in San Francisco Bay. On 9 May 1912, the first take off of an airplane from a ship while underway was made by Commander Charles Samson flying a Short Improved S.27 biplane "S.38" of the Royal Naval Air Service (RNAS) from the deck of the Royal Navy's pre-dreadnought battleship , thus providing the first practical demonstration of the aircraft carrier for naval operations at sea. Seaplane tender support ships came next, with the French of 1911. Early in World War I, the Imperial Japanese Navy ship conducted the world's first carrier-launched air raid: on 6 September 1914, the Wakamiya used its crane to lower Farman seaplanes into the water. The Wakamiya attacked the Austro-Hungarian cruiser and the Imperial German gunboat Jaguar in Jiaozhou Bay off Qingdao; neither was hit. The first attack using an air-launched torpedo occurred on 2 August, when a torpedo was fired by Flight Commander Charles Edmonds from a Short Type 184 seaplane, launched from the seaplane carrier .269 Squadron History: 1914–1923 The first carrier-launched airstrike was the Tondern raid in July 1918. Seven Sopwith Camels were launched from the battlecruiser which had been completed as a carrier by replacing her planned forward turret with a flight deck and hangar prior to commissioning. The Camels attacked and damaged the German airbase at Tondern, Germany (modern day Tønder, Denmark), and destroyed two zeppelin airships.Probert, p. 46. The first landing of an airplane on a moving ship was by Squadron Commander Edwin Harris Dunning, when he landed his Sopwith Pup on HMS Furious in Scapa Flow, Orkney on 2 August 1917. Landing on the forward flight deck required the pilot to approach round the ship's superstructure, a difficult and dangerous manoeuver and Dunning was later killed when his airplane was thrown overboard while attempting another landing on Furious.The First World War: A Complete History by Sir Martin Gilbert HMS Furious was modified again when her rear turret was removed and another flight deck added over a second hangar for landing aircraft over the stern.Parkes, p. 622. Her funnel and superstructure remained intact however and turbulence from the funnel and superstructure was severe enough that only three landing attempts were successful before further attempts were forbidden.Parkes, p. 624. This experience prompted the development of vessels with a flush deck and produced the first large fleet ships. In 1918, became the world's first carrier capable of launching and recovering naval aircraft. As a result of the Washington Naval Treaty of 1922, which limited the construction of new heavy surface combat ships, most early aircraft carriers were conversions of ships that were laid down (or had served) as different ship types: cargo ships, cruisers, battlecruisers, or battleships. These conversions gave rise to the in 1922, the US s (1927), Japanese and , and British (of which Furious was one). Specialist carrier evolution was well underway, with several navies ordering and building warships that were purposefully designed to function as aircraft carriers by the mid-1920s. This resulted in the commissioning of ships such as the Japanese (1922), (1924, although laid down in 1918 before Hōshō), and (1927). During World War II, these ships would become known as fleet carriers.
Aircraft carrier	World War II	World War II thumb\|, the most decorated US warship of World War II thumb\|The Japanese carrier Shinano was built on a battleship hull to carry spare aircraft and ordnance in support of other carriers. En route to complete fitting out it was sunk by an American submarine.Enright & Ryan, p. xiv. The aircraft carrier dramatically changed naval warfare in World War II, because air power was becoming a significant factor in warfare. The advent of aircraft as focal weapons was driven by the superior range, flexibility, and effectiveness of carrier-launched aircraft. They had greater range and precision than naval guns, making them highly effective. The versatility of the carrier was demonstrated in November 1940, when launched a long-range strike on the Italian fleet at their base in Taranto, signalling the beginning of the effective and highly mobile aircraft strikes. This operation in the shallow water harbor incapacitated three of the six anchored battleships at a cost of two torpedo bombers. World War II in the Pacific Ocean involved clashes between aircraft carrier fleets. The Japanese surprise attack on the American Pacific fleet at Pearl Harbor naval and air bases on Sunday, 7 December 1941, was a clear illustration of the power projection capability afforded by a large force of modern carriers. Concentrating six carriers in a single unit turned naval history about, as no other nation had fielded anything comparable. In the "Doolittle Raid", on 18 April 1942, the US Navy carrier sailed to within of Japan and launched 16 B-25 Mitchell medium bombers from her deck in a demonstrative retaliatory strike on the mainland, including the capital, Tokyo. However, the vulnerability of carriers compared to traditional capital ships was illustrated by the sinking of by German battleships during the Norwegian campaign in 1940. This new-found importance of naval aviation forced nations to create a number of carriers, in efforts to provide air superiority cover for every major fleet to ward off enemy aircraft. This extensive usage led to the development and construction of 'light' carriers. Escort aircraft carriers, such as , were sometimes purpose-built but most were converted from merchant ships as a stop-gap measure to provide anti-submarine air support for convoys and amphibious invasions. Following this concept, light aircraft carriers built by the US, such as (commissioned in 1943), represented a larger, more "militarized" version of the escort carrier. Although with similar complement to escort carriers, they had the advantage of speed from their converted cruiser hulls. The UK 1942 Design Light Fleet Carrier was designed for building quickly by civilian shipyards and with an expected service life of about 3 years. They served the Royal Navy during the war, and the hull design was chosen for nearly all aircraft carrier equipped navies after the war, until the 1980s. Emergencies also spurred the creation or conversion of highly unconventional aircraft carriers. CAM ships were cargo-carrying merchant ships that could launch (but not retrieve) a single fighter aircraft from a catapult to defend the convoy from long range land-based German aircraft.
Aircraft carrier	Postwar era	Postwar era alt=\|thumb\|An F6F-5 landing on the French Arromanches in the Tonkin Gulf, 1953 thumb\|USS Tripoli, a U.S. Navy Iwo Jima-class helicopter carrier thumb\|, the world's first nuclear-powered carrier, commissioned in 1961 Before World War II, international naval treaties of 1922, 1930, and 1936 limited the size of capital ships, including carriers. Since World War II, aircraft carrier designs have increased in size to accommodate a steady increase in aircraft size. The large, modern of US Navy carriers has a displacement nearly four times that of the World War II–era , yet its complement of aircraft is roughly the same—a consequence of the steadily increasing size and weight of individual military aircraft over the years. Today's aircraft carriers are so expensive that some nations which operate them risk significant economic and military impact if a carrier is lost. thumb\|Fighting the fire on board USS Forrestal, 1967 Some changes were made after 1945 in carriers: The angled flight deck was invented by Royal Navy Captain (later Rear Admiral) Dennis Cambell, as naval aviation jets' higher speeds required carriers be modified to fit their needs.; abridged findings published as Additionally, the angled flight deck allows for simultaneous launch and recovery. Jet blast deflectors became necessary to protect aircraft and handlers from jet blast. The first US Navy carriers to be fitted with them were the wooden-decked s which were adapted to operate jets in the late 1940s. Later versions had to be water-cooled because of increasing engine power. Optical landing systems were developed to facilitate the very precise landing angles required by jet aircraft, which have a faster landing speed giving the pilot little time to correct misalignments, or mistakes. The first system was fitted to in 1952. Aircraft carrier designs have increased in size to accommodate continuous increase in aircraft size. The 1950s saw US Navy's commission of "supercarriers", designed to operate naval jets, which offered better performance at the expense of bigger size and demanded more ordnance to be carried on-board (fuel, spare parts, electronics, etc.). The combination of increased carrier size, speed requirements above , and a requirement to operate at sea for long periods mean that modern large aircraft carriers often use nuclear reactors to create power for propulsion, electricity, catapulting airplanes from aircraft carriers, and a few more minor uses. Modern navies that operate such aircraft carriers treat them as capital ships of fleets, a role previously held by the galleons, ships-of-the-line and battleships. This change took place during World War II in response to air power becoming a significant factor in warfare, driven by the superior range, flexibility and effectiveness of carrier-launched aircraft. Following the war, carrier operations continued to increase in size and importance, and along with, carrier designs also increased in size and ability. Some of these larger carriers, dubbed by the media as "supercarriers", displacing 75,000 tons or greater, have become the pinnacle of carrier development. Some are powered by nuclear reactors and form the core of a fleet designed to operate far from home. Amphibious assault ships, such as the and classes, serve the purpose of carrying and landing Marines, and operate a large contingent of helicopters for that purpose. Also known as "commando carriers"A number of British conversions of light fleet carriers to helicopter operations were known as commando carriers, though they did not operate landing craft or "helicopter carriers", many have the capability to operate VSTOL aircraft. The threatening role of aircraft carriers has a place in modern asymmetric warfare, like the gunboat diplomacy of the past. Carriers also facilitate quick and precise projections of overwhelming military power into such local and regional conflicts. Lacking the firepower of other warships, carriers by themselves are considered vulnerable to attack by other ships, aircraft, submarines, or missiles. Therefore, an aircraft carrier is generally accompanied by a number of other ships to provide protection for the relatively unwieldy carrier, to carry supplies, re-supply (Many carriers are self-sufficient and will supply their escorts) and perform other support services, and to provide additional offensive capabilities. The resulting group of ships is often termed a carrier strike group, battle group, carrier group, or carrier battle group. There is a view among some military pundits that modern anti-ship weapons systems, such as torpedoes and missiles, or even ballistic missiles with nuclear warheads have made aircraft carriers and carrier groups too vulnerable for modern combat. Carriers can also be vulnerable to diesel-electric submarines like the German U24 of the conventional 206 class which in 2001 "fired" at the Enterprise during the exercise JTFEX 01-2 in the Caribbean Sea by firing flares and taking a photograph through its periscope or the Swedish Gotland which managed the same feat in 2006 during JTFEX 06-2 by penetrating the defensive measures of Carrier Strike Group 7 which was protecting .
Aircraft carrier	Description	Description
Aircraft carrier	Structure	Structure Carriers are large and long ships, although there is a high degree of variation depending on their intended role and aircraft complement. The size of the carrier has varied over history and among navies, to cater to the various roles that global climates have demanded from naval aviation. Regardless of size, the ship itself must house their complement of aircraft, with space for launching, storing, and maintaining them. Space is also required for the large crew, supplies (food, munitions, fuel, engineering parts), and propulsion. US aircraft carriers are notable for having nuclear reactors powering their systems and propulsion. thumb\|The first carrier landing and take-off of a jet aircraft: Eric "Winkle" Brown landing on in 1945 The top of the carrier is the flight deck, where aircraft are launched and recovered. On the starboard side of this is the island, where the funnel, air-traffic control and the bridge are located. The constraints of constructing a flight deck affect the role of a given carrier strongly, as they influence the weight, type, and configuration of the aircraft that may be launched. For example, assisted launch mechanisms are used primarily for heavy aircraft, especially those loaded with air-to-ground weapons. CATOBAR is most commonly used on US Navy fleet carriers as it allows the deployment of heavy jets with full load-outs, especially on ground-attack missions. STOVL is used by other navies because it is cheaper to operate and still provides good deployment capability for fighter aircraft. Due to the busy nature of the flight deck, only 20 or so aircraft may be on it at any one time. A hangar storage several decks below the flight deck is where most aircraft are kept, and aircraft are taken from the lower storage decks to the flight deck through the use of an elevator. The hangar is usually quite large and can take up several decks of vertical space. Munitions are commonly stored on the lower decks because they are highly explosive. Usually this is below the waterline so that the area can be flooded in case of emergency.
Aircraft carrier	Flight deck	Flight deck thumb\|Catapult launches aboard As "runways at sea", aircraft carriers have a flat-top flight deck, which launches and recovers aircraft. Aircraft launch forward, into the wind, and are recovered from astern. The flight deck is where the most notable differences between a carrier and a land runway are found. Creating such a surface at sea poses constraints on the carrier. For example, the size of the vessel is a fundamental limitation on runway length. This affects take-off procedure, as a shorter runway length of the deck requires that aircraft accelerate more quickly to gain lift. This either requires a thrust boost, a vertical component to its velocity, or a reduced take-off load (to lower mass). The differing types of deck configuration, as above, influence the structure of the flight deck. The form of launch assistance a carrier provides is strongly related to the types of aircraft embarked and the design of the carrier itself. There are two main philosophies to keep the deck short: add thrust to the aircraft, such as using a Catapult Assisted Take-Off (CATO-); and changing the direction of the airplanes' thrust, as in Vertical and/or Short Take-Off (V/STO-). Each method has advantages and disadvantages of its own: Catapult Assisted Take-Off Barrier Arrested Recovery (CATOBAR): A steam- or electric-powered catapult is connected to the aircraft, and is used to accelerate conventional aircraft to a safe flying speed. By the end of the catapult stroke, the aircraft is airborne and further propulsion is provided by its own engines. This is the most expensive method as it requires complex machinery to be installed under the flight deck, but allows for even heavily loaded aircraft to take off. Short Take-Off Barrier Arrested Recovery (STOBAR) depends on increasing the net lift on the aircraft. Aircraft do not require catapult assistance for take off; instead on nearly all ships of this type an upwards vector is provided by a ski-jump at the forward end of the flight deck, often combined with thrust vectoring by the aircraft. Alternatively, by reducing the fuel and weapon load, an aircraft is able to reach faster speeds and generate more upwards lift and launch without a ski-jump or catapult. Short Take-Off Vertical-Landing (STOVL): On aircraft carriers, non-catapult-assisted, fixed-wing short takeoffs are accomplished with the use of thrust vectoring, which may also be used in conjunction with a runway "ski-jump". Use of STOVL tends to allow aircraft to carry a larger payload as compared to during VTOL use, while still only requiring a short runway. The most famous examples are the Hawker Siddeley Harrier and the BAe Sea Harrier. Although technically VTOL aircraft, they are operationally STOVL aircraft due to the extra weight carried at take-off for fuel and armaments. The same is true of the Lockheed F-35B Lightning II, which demonstrated VTOL capability in test flights but is operationally STOVL or in the case of UK uses "shipborne rolling vertical landing". Vertical Take-Off and Landing (VTOL): Certain aircraft are specifically designed for the purpose of using very high degrees of thrust vectoring (e.g. if the thrust to weight-force ratio is greater than 1, it can take off vertically), but are usually slower than conventionally propelled aircraft due to the additional weight from associated systems. On the recovery side of the flight deck, the adaptation to the aircraft load-out is mirrored. Non-VTOL or conventional aircraft cannot decelerate on their own, and almost all carriers using them must have arrested-recovery systems (-BAR, e.g. CATOBAR or STOBAR) to recover their aircraft. Aircraft that are landing extend a tailhook that catches on arrestor wires stretched across the deck to bring themselves to a stop in a short distance. Post-World War II Royal Navy research on safer CATOBAR recovery eventually led to universal adoption of a landing area angled off axis to allow aircraft who missed the arresting wires to "bolt" and safely return to flight for another landing attempt rather than crashing into aircraft on the forward deck. If the aircraft are VTOL-capable or helicopters, they do not need to decelerate and hence there is no such need. The arrested-recovery system has used an angled deck since the 1950s because, in case the aircraft does not catch the arresting wire, the short deck allows easier take off by reducing the number of objects between the aircraft and the end of the runway. It also has the advantage of separating the recovery operation area from the launch area. Helicopters and aircraft capable of vertical or short take-off and landing (V/STOL) usually recover by coming abreast of the carrier on the port side and then using their hover capability to move over the flight deck and land vertically without the need for arresting gear.
Aircraft carrier	Staff and deck operations	Staff and deck operations thumb\|left\|F/A-18 Hornet aircraft landing video Carriers steam at speed, up to into the wind during flight deck operations to increase wind speed over the deck to a safe minimum. This increase in effective wind speed provides a higher launch airspeed for aircraft at the end of the catapult stroke or ski-jump, as well as making recovery safer by reducing the difference between the relative speeds of the aircraft and ship. Since the early 1950s on conventional carriers it has been the practice to recover aircraft at an angle to port of the axial line of the ship. The primary function of this angled deck is to allow aircraft that miss the arresting wires, referred to as a bolter, to become airborne again without the risk of hitting aircraft parked forward. The angled deck allows the installation of one or two "waist" catapults in addition to the two bow cats. An angled deck also improves launch and recovery cycle flexibility with the option of simultaneous launching and recovery of aircraft. Conventional ("tailhook") aircraft rely upon a landing signal officer (LSO, radio call sign 'paddles') to monitor the aircraft's approach, visually gauge glideslope, attitude, and airspeed, and transmit that data to the pilot. Before the angled deck emerged in the 1950s, LSOs used colored paddles to signal corrections to the pilot (hence the nickname). From the late 1950s onward, visual landing aids such as the optical landing system have provided information on proper glide slope, but LSOs still transmit voice calls to approaching pilots by radio. Key personnel involved in the flight deck include the shooters, the handler, and the air boss. Shooters are naval aviators or naval flight officers and are responsible for launching aircraft. The handler works just inside the island from the flight deck and is responsible for the movement of aircraft before launching and after recovery. The "air boss" (usually a commander) occupies the top bridge (Primary Flight Control, also called primary or the tower) and has the overall responsibility for controlling launch, recovery and "those aircraft in the air near the ship, and the movement of planes on the flight deck, which itself resembles a well-choreographed ballet". The captain of the ship spends most of his time one level below primary on the Navigation Bridge. Below this is the Flag Bridge, designated for the embarked admiral and his staff. To facilitate working on the flight deck of a US aircraft carrier, the sailors wear colored shirts that designate their responsibilities. There are at least seven different colors worn by flight deck personnel for modern United States Navy carrier air operations. Carrier operations of other nations use similar color schemes.
Aircraft carrier	Deck structures	Deck structures thumb\|Island control structure of alt=\|thumb\|The command bridge of the aircraft carrier The superstructure of a carrier (such as the bridge, flight control tower) are concentrated in a relatively small area called an island, a feature pioneered on in 1923. While the island is usually built on the starboard side of the flight deck, the Japanese aircraft carriers and had their islands built on the port side. Very few carriers have been designed or built without an island. The flush deck configuration proved to have significant drawbacks, primary of which was management of the exhaust from the power plant. Fumes coming across the deck were a major issue in . In addition, lack of an island meant difficulties managing the flight deck, performing air traffic control, a lack of radar housing placements and problems with navigating and controlling the ship itself. Another deck structure that can be seen is a ski-jump ramp at the forward end of the flight deck. This was first developed to help launch short take off vertical landing (STOVL) aircraft take off at far higher weights than is possible with a vertical or rolling takeoff on flat decks. Originally developed by the Royal Navy, it since has been adopted by many navies for smaller carriers. A ski-jump ramp works by converting some of the forward rolling movement of the aircraft into vertical velocity and is sometimes combined with the aiming of jet thrust partly downward. This allows heavily loaded and fueled aircraft a few more precious seconds to attain sufficient air velocity and lift to sustain normal flight. Without a ski-jump, launching fully-loaded and fueled aircraft such as the Harrier would not be possible on a smaller flat deck ship before either stalling out or crashing directly into the sea. Although STOVL aircraft are capable of taking off vertically from a spot on the deck, using the ramp and a running start is far more fuel efficient and permits a heavier launch weight. As catapults are unnecessary, carriers with this arrangement reduce weight, complexity, and space needed for complex steam or electromagnetic launching equipment. Vertical landing aircraft also remove the need for arresting cables and related hardware. Russian, Chinese, and Indian carriers include a ski-jump ramp for launching lightly loaded conventional fighter aircraft but recover using traditional carrier arresting cables and a tailhook on their aircraft. The disadvantage of the ski-jump is the penalty it exacts on aircraft size, payload, and fuel load (and thus range); heavily laden aircraft cannot launch using a ski-jump because their high loaded weight requires either a longer takeoff roll than is possible on a carrier deck, or assistance from a catapult or JATO rocket. For example, the Russian Sukhoi Su-33 is only able to launch from the carrier with a minimal armament and fuel load. Another disadvantage is on mixed flight deck operations where helicopters are also present, such as on a US landing helicopter dock or landing helicopter assault amphibious assault ship. A ski jump is not included as this would eliminate one or more helicopter landing areas; this flat deck limits the loading of Harriers but is somewhat mitigated by the longer rolling start provided by a long flight deck compared to many STOVL carriers.
Aircraft carrier	National fleets	National fleets thumb\|upright=1.5\| The US Navy has the largest fleet of carriers in the world, with eleven supercarriers in service as of 2024. China and India each have two STOBAR carriers in service. The UK has two STOVL carriers in service. The navies of France and Russia each operate a single medium-sized carrier. The US also has nine similarly sized Amphibious Warfare Ships. There are five small light carriers in use capable of operating both fixed-wing aircraft and helicopters; Japan and Italy each operate two, and Spain one. Additionally there are nineteen small carriers which only operate helicopters serving the navies of Australia (2), Brazil (1), China (2), Egypt (2), France (3), Japan (4), South Korea (2), Thailand (1), Turkey (1), and Iran (1).
Aircraft carrier	Algeria	Algeria Current Kalaat Béni Abbès (L-474) is an amphibious transport dock of the Algerian National Navy with two deck-landing spots for helicopters.
Aircraft carrier	Australia	Australia thumb\|, a Current The Royal Australian Navy operates two s. The two-ship class, based on the Spanish vessel and built by Navantia and BAE Systems Australia, represents the largest ships ever built for the Royal Australian Navy. underwent sea trials in late 2013 and was commissioned in 2014. Her sister ship, , was commissioned in December 2015. The Australian ships retain the ski-ramp from the Juan Carlos I design, although the RAN has not acquired carrier-based fixed-wing aircraft.
Aircraft carrier	Brazil	Brazil Current In December 2017, the Brazilian Navy confirmed the purchase of for (GBP) £84.6 million (equivalent to R$359.5M and US$113.2M) and renamed her . The ship was decommissioned from Royal Navy service in March 2018. The Brazilian Navy commissioned the carrier on 29 June 2018 in the United Kingdom. After undertaking a period of maintenance in the UK, the ship travelled to its new home port, Arsenal de Marinha do Rio de Janeiro (AMRJ) to be fully operational by 2020. The ship displaces 21,578 tonnes, is long and has a range of . Before leaving HMNB Devonport for her new homeport in Rio's AMRJ, Atlântico underwent operational sea training under the Royal Navy's Flag Officer Sea Training (FOST) program. On 12 November 2020, Atlântico was redesignated "NAM", for "multipurpose aircraft carrier" (), from "PHM", for "multipurpose helicopter carrier" (), to reflect the ship's capability to operate with fixed-wing medium-altitude long-endurance unmanned aerial vehicles as well as crewed tiltrotor VTOL aircraft.
Aircraft carrier	China	China thumb\|, a Type 002 aircraft carrier Current Two STOBAR carriers: (60,900 tons) was originally built as the uncompleted Soviet carrier Varyag and was later purchased as a hulk from Ukraine in 1998 on the pretext of commercial use as a floating casino, then towed to China for rebuild and completion. Liaoning was commissioned on 25 September 2012 and began service for testing and training. In November 2012, Liaoning launched and recovered Shenyang J-15 naval fighter aircraft for the first time. After a refit in January 2019, she was assigned to the North Sea Fleet, a change from her previous role as a training ship. (60,000–70,000 tons) was launched on 26 April 2017, the first to be built domestically based on an improved Kuznetsov-class design. Shandong started sea trials on 23 April 2018, and entered service in December 2019. One CATOBAR carrier: (80,000 tons) is a conventionally powered CATOBAR carrier that was under construction between 2015 and 2016 before being completed in June 2022. She is being fitted out as of 2022 and will commence service in 2023–2024. 3 LHD amphibious assault ships A Type 075 LHD, was commissioned on 23 April 2021 at the South Sea Fleet naval base in Sanya. A second ship, Guangxi, was commissioned on 26 December 2021 and a third ship, Anhui, was commissioned in October 2022. Future China has had a long-term plan to operate six large aircraft carriers with two carriers per fleet. China is planning a class of eight LHD vessels, the Type 075 (NATO reporting name Yushen-class landing helicopter assault). This is a class of amphibious assault ship under construction by the Hudong–Zhonghua Shipbuilding company. The first ship was commissioned in April 2021. China is also planning a modified class of the same concept, the Type 076 landing helicopter dock, that will be equipped with an electromagnetic catapult system and will likely support launching unmanned combat aerial vehicles.
Aircraft carrier	Egypt	Egypt Current Egypt signed a contract with French shipbuilder DCNS to buy two helicopter carriers for approximately 950 million euros. The two ships were originally to be sold to Russia, but the deal was cancelled by France due to the Russian invasion of Ukraine in 2014. On 2 June 2016, Egypt received the first of two helicopter carriers acquired in October 2015, the landing helicopter dock . The flag transfer ceremony took place in the presence of Egyptian and French Navies' chiefs of staff, chairman and chief executive officers of both DCNS and STX France, and senior Egyptian and French officials. On 16 September 2016, DCNS delivered the second of two helicopter carriers, the landing helicopter dock which also participated in a joint military exercise with the French Navy before arriving at her home port of Alexandria.
Aircraft carrier	France	France thumb\|right\|The aircraft carrier of the French Navy Current The French Navy operates the 42,000-tonne nuclear-powered aircraft carrier, . Commissioned in 2001, she is the flagship of the French Navy. The ship carries a complement of Dassault Rafale M and E-2C Hawkeye aircraft, EC725 Caracal and AS532 Cougar helicopters for combat search and rescue, as well as modern electronics and Aster missiles. She is a CATOBAR-type carrier that uses two 75 m C13-3 steam catapults of a shorter version of the catapult system installed on the US carriers, one catapult at the bow and one across the front of the landing area. In addition, the French Navy operates three s. Future In October 2018, the French Ministry of Defence began an 18-month €40 million study for the replacement of the sometime after 2030. In December 2020, President Macron announced that construction of the next generation carrier would begin in around 2025 with sea trials to start in about 2036. The carrier is planned to have a displacement of around 75,000 tons and to carry about 32 next-generation fighters, two to three E-2D Advanced Hawkeyes and a yet-to-be-determined number of unmanned carrier air vehicles.
Aircraft carrier	India	India thumb\| (IAC-1) at sea during her maiden sea trials Current Two STOBAR carriers: , 45,400 tonnes, modified Kiev class. The carrier was purchased by India on 20 January 2004 after years of negotiations at a final price of $2.35 billion (). The ship successfully completed her sea trials in July 2013 and aviation trials in September 2013. She was formally commissioned on 16 November 2013 at a ceremony held at Severodvinsk, Russia. , also known as Indigenous Aircraft Carrier 1 (IAC-1) a 45,000-tonne, aircraft carrier whose keel was laid in 2009. The new carrier will operate MiG-29K and naval HAL Tejas aircraft. The ship is powered by gas-turbines and has a range of and deploys 10 helicopters and 30 aircraft. The ship was launched in 2013, sea-trials began in August 2021 and was commissioned on 2 September 2022. Future India has plans for a third carrier, , also known as Indigenous Aircraft Carrier 2 (IAC-2) with a displacement of over 65,000 tonnes and is planned with a CATOBAR system to launch and recover heavier aircraft. India has also issued a request for information (RFI) to procure four Landing helicopter dock displacing 30,000–40,000 tons with a capacity to operate 12 medium lift special ops and two heavy lift helicopters and troops for amphibious operations.
Aircraft carrier	Italy	Italy thumb\|Italian aircraft carrier Cavour (550) Current One STOVL carrier: : 30,000-tonne Italian STOVL carrier designed and built with secondary amphibious assault facilities, commissioned in 2008. Future thumb\|Italian LHD Trieste (L 9890) Italy plans to replace the now decommissioned aircraft carrier Giuseppe Garibaldi, as well as one of the landing helicopter docks, with a new amphibious assault ship, to be named . The ship will be significantly larger than her predecessors with a displacement of 38,000 tonnes at full load. Trieste is to carry the F-35B Joint Strike Fighter. Meanwhile, Giuseppe Garibaldi will be transferred to Italian Space Operation Command for use as a satellite launch platform.
Aircraft carrier	Iran	Iran
Aircraft carrier	Current	Current One drone carrier: IRIS Shahid Bagheri: a 41,978-tonne drone UAV carrier converted from a container ship. Commissioned in 2025.
Aircraft carrier	Japan	Japan thumb\|Helicopter carrier Izumo (DDH-183) at sea Current Two s – , 19,500-tonne (27,000 tonnes full load) STOVL carrier Izumo was launched August 2013 and commissioned March 2015. Izumos sister ship, Kaga, was commissioned in 2017. In December 2018, the Japanese Cabinet gave approval to convert both Izumo-class destroyers into aircraft carriers for F-35B STOVL operations. The conversion of Izumo was underway as of mid-2020. The modification of maritime escort vessels is to "increase operational flexibility" and enhance Pacific air defense, the Japanese defense ministry's position is "We are not creating carrier air wings or carrier air squadrons" similar to the US Navy. The Japanese STOVL F-35s, when delivered, will be operated by the Japan Air Self Defense Force from land bases; according to the 2020 Japanese Defense Ministry white paper the STOVL model was chosen for the JASDF due the lack of appropriately long runways to support air superiority capability across all of Japanese airspace. Japan has requested that the USMC deploy STOVL F-35s and crews aboard the Izumo-class ships "for cooperation and advice on how to operate the fighter on the deck of the modified ships". On 3 October 2021, two USMC F-35Bs performed the first vertical landings and horizontal take-offs from JS Izumo, marking 75 years since fixed-wing aircraft operated from a Japanese carrier. Two s – 19,000-tonne (full load) anti-submarine warfare carriers with enhanced command-and-control capabilities allowing them to serve as fleet flagships.
Aircraft carrier	Qatar	Qatar Current Qatari amphibious transport dock Al Fulk
Aircraft carrier	Russia	Russia thumb\| Current One STOBAR carrier: Admiral Flota Sovetskogo Soyuza Kuznetsov: 55,000-tonne STOBAR aircraft carrier. Launched in 1985 as Tbilisi, renamed and operational from 1995. Without catapults she can launch and recover lightly fueled naval fighters for air defense or anti-ship missions but not heavy conventional bombing strikes. Officially designated an aircraft carrying cruiser, she is unique in carrying a heavy cruiser's complement of defensive weapons and large P-700 Granit offensive missiles. The P-700 systems will be removed in the coming refit to enlarge her below decks aviation facilities as well as upgrading her defensive systems. The ship has been out of service and in repairs since 2018. The current projection is that repairs will be completed and the ship will be transferred back to the Russian Navy sometime in 2024, however this may be pushed back to 2025 if issues arise during overhaul and testing. Future The Russian government has been considering the potential replacement of Admiral Kuznetsov for some time and has considered the Shtorm-class aircraft carrier as a possible option. This carrier will be a hybrid of CATOBAR and STOBAR, given the fact that she uses both systems of launching aircraft. The carrier is expected to cost As of 2020, the project had not yet been approved and, given the financial costs, it was unclear whether it would be made a priority over other elements of Russian naval modernization. A class of 2 LHD, Project 23900 is planned and an official keel laying ceremony for the project happened on 20 July 2020.
Aircraft carrier	South Korea	South Korea thumb\|Conceptual model of CVX-class aircraft carrier Current Two 18,860-tonne full deck amphibious assault ships with hospital and well deck and facilities to serve as fleet flagships. Future South Korea has set tentative plans for procuring two light aircraft carriers by 2033, which would help make the ROKN a blue water navy. In December 2020, details of South Korea's planned carrier program (CVX) were finalized. A vessel of about 40,000 tons is envisaged carrying about 20 F-35B fighters as well as future maritime attack helicopters. Service entry had been anticipated in the early 2030s. The program has encountered opposition in the National Assembly. In November 2021, the National Defense Committee of the National Assembly reduced the program's requested budget of 7.2 billion KRW and to just 500 million KRW (about $400K USD), effectively putting the project on hold, at least temporarily. However, on 3 December 2021 the full budget of 7.2 billion won was passed by the National Assembly. Basic design work is to begin in earnest starting 2022.
Aircraft carrier	Spain	Spain thumb\|Spanish Juan Carlos I with Harrier II Current : a 27,000-tonne, specially designed multipurpose strategic projection ship which can operate as an amphibious assault ship and as an aircraft carrier. Juan Carlos I has full facilities for both functions including a ski jump for STOVL operations, is equipped with the AV-8B Harrier II attack aircraft. She also features a well deck and a vehicle storage area which can be used as additional hangar space. The vessel was launched in 2008 and commissioned on 30 September 2010.
Aircraft carrier	Thailand	Thailand thumb\|right\|The aircraft carrier of the Royal Thai Navy Current One offshore helicopter support ship: helicopter carrier: 11,400-tonne STOVL carrier based on Spanish design. Commissioned in 1997. The AV-8S Matador/Harrier STOVL fighter wing, mostly inoperable by 1999, was retired from service without replacement in 2006. As of 2010, the ship is used for helicopter operations and for disaster relief.
Aircraft carrier	Turkey	Turkey thumb\|TCG Anadolu (L-400) at the Bosporus strait during the naval parade for celebrating the centenary of the Turkish Republic on 29 October 2023 Current is a 27,079-tonne amphibious assault ship (LHD) (outfitted as drone carrier) of the Turkish Navy that can be configured as a 24,660-tonne V/STOL aircraft carrier. Construction began on 30 April 2016 by Sedef Shipbuilding Inc. at their Istanbul shipyard. TCG Anadolu was commissioned with a ceremony on 10 April 2023. The construction of a sister ship, to be named TCG Trakya, is currently being planned by the Turkish Navy. The Sikorsky S-70B Seahawk and the Bell AH-1 SuperCobra are the two main types of helicopters used on TCG Anadolu, with the occasional use of CH-47F Chinook helicopters of the Turkish Army during military exercises and operations. The AH-1W Super Cobras will eventually be complemented and replaced by the TAI T929 ATAK 2. The jet-powered, low-observable drone Bayraktar MIUS Kızılelma and the MALE UAV Bayraktar TB3 are two UCAVs that are specifically designed and manufactured by Baykar Technologies to be used on TCG Anadolu. The maiden flight of TAI Anka-3 (also part of Project MIUS), a jet-powered, flying wing type UCAV with stealth technology, was successfully completed on 28 December 2023. On 19 November 2024, Baykar Bayraktar TB3 UCAV successfully took-off from the flight deck of TCG Anadolu and landed on the ship. It was the first time a fixed-wing unmanned aircraft of this size and class had successfully landed on a short-runway landing helicopter dock, without the use of an arresting gear. Future On 3 January 2024, the Turkish government approved the plan for the design and construction of a larger aircraft carrier, named the MUGEM-class. On 15 February 2024, the Design and Projects Office of the Turkish Navy announced that it will be a STOBAR aircraft carrier with an overall length of , beam of , draught of , and displacement of 60,000 tons. It is to have a COGAG propulsion system and a maximum speed of more than . The construction of the first MUGEM-class aircraft carrier began on 2 January 2025. The first MUGEM-class aircraft carrier is being built at the Istanbul Naval Shipyard.
Aircraft carrier	United Kingdom	United Kingdom thumb\|A Merlin HM2 AEW on 's flight deck Current Two 80,600-tonne (est. full load) Queen Elizabeth-class STOVL carriers which operate the F-35 Lightning II. was commissioned in December 2017 and in December 2019. Queen Elizabeth undertook her first operational deployment in 2021. Each Queen Elizabeth-class ship is able to operate around 40 aircraft during peacetime operations and is thought to be able to carry up to 72 at maximum capacity. As of the end of April 2020, 18 F-35B aircraft had been delivered to the Royal Navy and the Royal Air Force. "Full operating capability" for the UK's carrier strike capability had been planned for 2023 (two squadrons or 24 jets operating from one carrier). The longer-term aim remains for the ability to conduct a wide range of air operations and support amphibious operations worldwide from both carriers by 2026. They form the central part of the UK Carrier Strike Group. The Queen Elizabeth-class ships are expected to have service lives of 50 years.
Aircraft carrier	United States	United States thumb\|, the third US Navy carrier to bear the name, is a Gerald R. Ford-class carrier under construction as of 2025 and is expected to enter service in 2028. Current Eleven CATOBAR carriers, all nuclear-powered: : ten 101,000-tonne, fleet carriers, the first of which was commissioned in 1975. A Nimitz-class carrier is powered by two nuclear reactors providing steam to four steam turbines. , one 100,000-tonne, fleet carrier. The lead of the class came into service in 2017, with another nine planned to replace the aging Nimitz-class ships. Nine amphibious assault ships carrying vehicles, Marine fighters, attack and transport helicopters, and landing craft with STOVL fighters for Close Air Support (CAS) and Combat Air Patrol (CAP): : a class of 45,000-tonne amphibious assault ships, although the first two ships in this class, (Flight 0) do not have well decks, all subsequent ships (Flight I) are to have well decks. Two ships are currently in service out of a planned 11 ships. Ships of this class can have a secondary mission as a light aircraft carrier with 20 AV-8B Harrier II, and in the future the F-35B Lightning II aircraft after unloading their Marine expeditionary unit. : a class of 41,000-tonne amphibious assault ships, members of this class have been used in wartime in their secondary mission as light carriers with 20 to 25 AV-8Bs after unloading their Marine expeditionary unit. Seven ship currently in service of an original eight, with one lost to fire. Future The current US fleet of Nimitz-class carriers will be followed into service (and in some cases replaced) by the . It is expected that the ships will be more automated in an effort to reduce the amount of funding required to maintain and operate the vessels. The main new features are implementation of Electromagnetic Aircraft Launch System (EMALS) (which replaces the old steam catapults) and unmanned aerial vehicles. In terms of future carrier developments, Congress has discussed the possibility of accelerating the phasing-out of one or more Nimitz-class carriers, postponing or canceling the procurement of CVN-81 and CVN-82, or modifying the purchase contract.O'Rourke, R. (2015). Navy Ford (CVN-78) Class Aircraft Carrier Program: Background and Issues for Congress. Congressional Research Service Washington. Following the deactivation of in December 2012, the US fleet comprised 10 fleet carriers, but that number increased back to 11 with the commissioning of Gerald R. Ford in July 2017. The House Armed Services Seapower subcommittee on 24 July 2007, recommended seven or eight new carriers (one every four years). However, the debate has deepened over budgeting for the $12–14.5 billion (plus $12 billion for development and research) for the 100,000-tonne Gerald R. Ford-class carrier (estimated service 2017) compared to the smaller $2 billion 45,000-tonne s, which are able to deploy squadrons of F-35Bs. The first of this class, , is now in active service with another, , and 9 more are planned. In a report to Congress in February 2018, the Navy stated it intends to maintain a "12 CVN force" as part of its 30-year acquisition plan.
Aircraft carrier	Aircraft carriers in preservation	Aircraft carriers in preservation
Aircraft carrier	Current museum carriers	Current museum carriers A few aircraft carriers have been preserved as museum ships. They are: in Mount Pleasant, South Carolina in New York City in Alameda, California in Corpus Christi, Texas in San Diego, California in Tianjin, China in Nantong, China
Aircraft carrier	Former museum carriers	Former museum carriers was moored as a museum in Mumbai from 2001 to 2012, but was never able to find an industrial partner and was closed that year. She was scrapped in 2014. was acquired for preservation by the Cabot Museum Foundation and moored in New Orleans from 1989 to 1997, but due to the Cabot Museum Foundation's failure to repay the U.S. Coast Guard over $1 million for removal of hazardous materials and fees associated with its docking, it was seized by the U.S. Marshals in 1999 and auctioned off to Sabe Marine Salvage. Scrapping of the ship began in November 2000.
Aircraft carrier	Planned but cancelled museum carriers	Planned but cancelled museum carriers had a preservation campaign to bring her to the West Coast of the United States as the world's first amphibious assault ship museum. However, at RIMPAC 2024, on 9 July 2024, the Tarawa was sunk alongside as SINKEXs.
Aircraft carrier	See also	See also Airborne aircraft carrier Aviation-capable naval vessel Carrier-based aircraft Drone carrier Lily and Clover Merchant aircraft carrier Mobile offshore base Project Habakkuk Seadrome Submarine aircraft carrier Unsinkable aircraft carrier
Aircraft carrier	Related lists	Related lists List of active French Navy ships List of active Italian Navy ships List of active Spanish aircraft carriers List of aircraft carrier classes of the United States Navy List of aircraft carriers List of aircraft carriers by configuration List of aircraft carriers in service List of aircraft carriers of Germany List of aircraft carriers of Russia and the Soviet Union List of aircraft carriers of the Indian Navy List of aircraft carriers of the Japanese Navy List of aircraft carriers of the People's Liberation Army Navy (China) List of aircraft carriers of the Royal Navy List of aircraft carriers of the United States Navy List of aircraft carriers of World War II List of amphibious warfare ships List of carrier-based aircraft List of current ships of the Royal Canadian Navy List of escort carriers of the Royal Navy List of escort carriers of the United States Navy List of seaplane carriers of the Royal Navy List of sunken aircraft carriers
Aircraft carrier	Notes	Notes
Aircraft carrier	References	References
Aircraft carrier	Bibliography	Bibliography
Aircraft carrier	Further reading	Further reading Ader, Clement. Military Aviation, 1909, Edited and translated by Lee Kennett, Air University Press, Maxwell Air Force Base, Alabama, 2003, . Chesneau, Roger. Aircraft Carriers of the World, 1914 to the Present: An Illustrated Encyclopedia. Naval Institute Press, 1984. Francillon, René J, Tonkin Gulf Yacht Club US Carrier Operations off Vietnam, 1988, . Melhorn, Charles M. Two-Block Fox: The Rise of the Aircraft Carrier, 1911–1929. Naval Institute Press, 1974. Nordeen, Lon, Air Warfare in the Missile Age, 1985, . Polmar, Norman. Aircraft Carriers: A History of Carrier Aviation and its Influence on World Events, 1901–2006. (two vols.) Potomac Books, 2006. Wadle, Ryan David. United States navy fleet problems and the development of carrier aviation, 1929–1933. PhD dissertation Texas A&M University, 2005. online.
Aircraft carrier	External links	External links – technical training film from the Royal Navy Category:Ship types Category:Articles containing video clips
Aircraft carrier	Table of Content	Short description, Types of carriers, General features, Basic types, By role, By configuration, By size, Supercarrier, Hull type identification symbols, History, Origins, World War II, Postwar era, Description, Structure, Flight deck, Staff and deck operations, Deck structures, National fleets, Algeria, Australia, Brazil, China, Egypt, France, India, Italy, Iran, Current, Japan, Qatar, Russia, South Korea, Spain, Thailand, Turkey, United Kingdom, United States, Aircraft carriers in preservation, Current museum carriers, Former museum carriers, Planned but cancelled museum carriers, See also, Related lists, Notes, References, Bibliography, Further reading, External links
Apicomplexa	Short description	The Apicomplexa (also called Apicomplexia; single: apicomplexan) are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of non-photosynthetic plastid called an apicoplastwith an apical complex membrane. The organelle's apical shape is an adaptation that the apicomplexan applies in penetrating a host cell. The Apicomplexa are unicellular and spore-forming. Most are obligate endoparasites of animals, except Nephromyces, a symbiont in marine animals, originally classified as a chytrid fungus, and the Chromerida, some of which are photosynthetic partners of corals. Motile structures such as flagella or pseudopods are present only in certain gamete stages. The Apicomplexa are a diverse group that includes organisms such as the coccidia, gregarines, piroplasms, haemogregarines, and plasmodia. Diseases caused by Apicomplexa include: Babesiosis (Babesia) Malaria (Plasmodium) Cryptosporidiosis (Cryptosporidium parvum) Cyclosporiasis (Cyclospora cayetanensis) Cystoisosporiasis (Cystoisospora belli) Toxoplasmosis (Toxoplasma gondii) The name Apicomplexa derives from two Latin words—apex (top) and complexus (infolds)—for the set of organelles in the sporozoite. The Apicomplexa comprise the bulk of what used to be called the Sporozoa, a group of parasitic protozoans, in general without flagella, cilia, or pseudopods. Most of the Apicomplexa are motile, however, with a gliding mechanism that uses adhesions and small static myosin motors. The other main lines of this obsolete grouping were the Ascetosporea (a group of Rhizaria), the Myxozoa (highly derived cnidarian animals), and the Microsporidia (derived from fungi). Sometimes, the name Sporozoa is taken as a synonym for the Apicomplexa, or occasionally as a subset.
Apicomplexa	Description	Description thumb\|Some cell types: ookinete, sporozoite, merozoite The phylum Apicomplexa contains all eukaryotes with a group of structures and organelles collectively termed the apical complex. This complex consists of structural components and secretory organelles required for invasion of host cells during the parasitic stages of the Apicomplexan life cycle. Apicomplexa have complex life cycles, involving several stages and typically undergoing both asexual and sexual replication. All Apicomplexa are obligate parasites for some portion of their life cycle, with some parasitizing two separate hosts for their asexual and sexual stages. Besides the conserved apical complex, Apicomplexa are morphologically diverse. Different organisms within Apicomplexa, as well as different life stages for a given apicomplexan, can vary substantially in size, shape, and subcellular structure. Like other eukaryotes, Apicomplexa have a nucleus, endoplasmic reticulum and Golgi complex. Apicomplexa generally have a single mitochondrion, as well as another endosymbiont-derived organelle called the apicoplast which maintains a separate 35 kilobase circular genome (with the exception of Cryptosporidium species and Gregarina niphandrodes which lack an apicoplast). All members of this phylum have an infectious stage—the sporozoite—which possesses three distinct structures in an apical complex. The apical complex consists of a set of spirally arranged microtubules (the conoid), a secretory body (the rhoptry) and one or more polar rings. Additional slender electron-dense secretory bodies (micronemes) surrounded by one or two polar rings may also be present. This structure gives the phylum its name. A further group of spherical organelles is distributed throughout the cell rather than being localized at the apical complex and are known as the dense granules. These typically have a mean diameter around 0.7 μm. Secretion of the dense-granule content takes place after parasite invasion and localization within the parasitophorous vacuole and persists for several minutes. Flagella are found only in the motile gamete. These are posteriorly directed and vary in number (usually one to three). Basal bodies are present. Although hemosporidians and piroplasmids have normal triplets of microtubules in their basal bodies, coccidians and gregarines have nine singlets. The mitochondria have tubular cristae. Centrioles, chloroplasts, ejectile organelles, and inclusions are absent. The cell is surrounded by a pellicle of three membrane layers (the alveolar structure) penetrated by micropores. center\|thumb\|upright=2\| Replication: Mitosis is usually closed, with an intranuclear spindle; in some species, it is open at the poles. Cell division is usually by schizogony. Meiosis occurs in the zygote. Mobility: Apicomplexans have a unique gliding capability which enables them to cross through tissues and enter and leave their host cells. This gliding ability is made possible by the use of adhesions and small static myosin motors. Other features common to this phylum are a lack of cilia, sexual reproduction, use of micropores for feeding, and the production of oocysts containing sporozoites as the infective form. Transposons appear to be rare in this phylum, but have been identified in the genera Ascogregarina and Eimeria.
Apicomplexa	Life cycle	Life cycle Most members have a complex lifecycle, involving both asexual and sexual reproduction. Typically, a host is infected via an active invasion by the parasites (similar to entosis), which divide to produce sporozoites that enter its cells. Eventually, the cells burst, releasing merozoites, which infect new cells. This may occur several times, until gamonts are produced, forming gametes that fuse to create new cysts. Many variations occur on this basic pattern, however, and many Apicomplexa have more than one host. The apical complex includes vesicles called rhoptries and micronemes, which open at the anterior of the cell. These secrete enzymes that allow the parasite to enter other cells. The tip is surrounded by a band of microtubules, called the polar ring, and among the Conoidasida is also a funnel of tubulin proteins called the conoid. Over the rest of the cell, except for a diminished mouth called the micropore, the membrane is supported by vesicles called alveoli, forming a semirigid pellicle. The presence of alveoli and other traits place the Apicomplexa among a group called the alveolates. Several related flagellates, such as Perkinsus and Colpodella, have structures similar to the polar ring and were formerly included here, but most appear to be closer relatives of the dinoflagellates. They are probably similar to the common ancestor of the two groups. Another similarity is that many apicomplexan cells contain a single plastid, called the apicoplast, surrounded by either three or four membranes. Its functions are thought to include tasks such as lipid and heme biosynthesis, and it appears to be necessary for survival. In general, plastids are considered to have a common origin with the chloroplasts of dinoflagellates, and evidence points to an origin from red algae rather than green.
Apicomplexa	Subgroups	Subgroups Within this phylum are four groups — coccidians, gregarines, haemosporidians (or haematozoans, including in addition piroplasms), and marosporidians. The coccidians and haematozoans appear to be relatively closely related. Perkinsus , while once considered a member of the Apicomplexa, has been moved to a new phylum — Perkinsozoa.
Apicomplexa	Gregarines	Gregarines thumb\|right\|100px\|Trophozoite of a gregarine The gregarines are generally parasites of annelids, arthropods, and molluscs. They are often found in the guts of their hosts, but may invade the other tissues. In the typical gregarine lifecycle, a trophozoite develops within a host cell into a schizont. This then divides into a number of merozoites by schizogony. The merozoites are released by lysing the host cell, which in turn invade other cells. At some point in the apicomplexan lifecycle, gametocytes are formed. These are released by lysis of the host cells, which group together. Each gametocyte forms multiple gametes. The gametes fuse with another to form oocysts. The oocysts leave the host to be taken up by a new host.
Apicomplexa	Coccidians	Coccidians thumb\|150px\|Dividing Toxoplasma gondii (Coccidia) parasites In general, coccidians are parasites of vertebrates. Like gregarines, they are commonly parasites of the epithelial cells of the gut, but may infect other tissues. The coccidian lifecycle involves merogony, gametogony, and sporogony. While similar to that of the gregarines it differs in zygote formation. Some trophozoites enlarge and become macrogamete, whereas others divide repeatedly to form microgametes (anisogamy). The microgametes are motile and must reach the macrogamete to fertilize it. The fertilized macrogamete forms a zygote that in its turn forms an oocyst that is normally released from the body. Syzygy, when it occurs, involves markedly anisogamous gametes. The lifecycle is typically haploid, with the only diploid stage occurring in the zygote, which is normally short-lived. The main difference between the coccidians and the gregarines is in the gamonts. In the coccidia, these are small, intracellular, and without epimerites or mucrons. In the gregarines, these are large, extracellular, and possess epimerites or mucrons. A second difference between the coccidia and the gregarines also lies in the gamonts. In the coccidians, a single gamont becomes a macrogametocyte, whereas in the gregarines, the gamonts give rise to multiple gametocytes.
Apicomplexa	Haemosporidia	Haemosporidia thumb\|150px\|upright=1.3\|Trophozoites of the Plasmodium vivax (Haemosporidia) parasite among human red blood cells The Haemosporidia have more complex lifecycles that alternate between an arthropod and a vertebrate host. The trophozoite parasitises erythrocytes or other tissues in the vertebrate host. Microgametes and macrogametes are always found in the blood. The gametes are taken up by the insect vector during a blood meal. The microgametes migrate within the gut of the insect vector and fuse with the macrogametes. The fertilized macrogamete now becomes an ookinete, which penetrates the body of the vector. The ookinete then transforms into an oocyst and divides initially by meiosis and then by mitosis (haplontic lifecycle) to give rise to the sporozoites. The sporozoites escape from the oocyst and migrate within the body of the vector to the salivary glands where they are injected into the new vertebrate host when the insect vector feeds again.
Apicomplexa	Marosporida	Marosporida The class Marosporida Mathur, Kristmundsson, Gestal, Freeman, and Keeling 2020 is a newly recognized lineage of apicomplexans that is sister to the Coccidia and Hematozoa. It is defined as a phylogenetic clade containing Aggregata octopiana Frenzel 1885, Merocystis kathae Dakin, 1911 (both Aggregatidae, originally coccidians), Rhytidocystis sp. 1 and Rhytidocystis sp. 2 Janouškovec et al. 2019 (Rhytidocystidae Levine, 1979, originally coccidians, Agamococcidiorida), and Margolisiella islandica Kristmundsson et al. 2011 (closely related to Rhytidocystidae). Marosporida infect marine invertebrates. Members of this clade retain plastid genomes and the canonical apicomplexan plastid metabolism. However, marosporidians have the most reduced apicoplast genomes sequenced to date, lack canonical plastidial RNA polymerase and so provide new insights into reductive organelle evolution.
Apicomplexa	Ecology and distribution	Ecology and distribution thumb\|Two tachyzoites of Toxoplasma gondii, transmission electron microscopy Many of the apicomplexan parasites are important pathogens of humans and domestic animals. In contrast to bacterial pathogens, these apicomplexan parasites are eukaryotic and share many metabolic pathways with their animal hosts. This makes therapeutic target development extremely difficult – a drug that harms an apicomplexan parasite is also likely to harm its human host. At present, no effective vaccines are available for most diseases caused by these parasites. Biomedical research on these parasites is challenging because it is often difficult, if not impossible, to maintain live parasite cultures in the laboratory and to genetically manipulate these organisms. In recent years, several of the apicomplexan species have been selected for genome sequencing. The availability of genome sequences provides a new opportunity for scientists to learn more about the evolution and biochemical capacity of these parasites. The predominant source of this genomic information is the EuPathDB family of websites, which currently provides specialised services for Plasmodium species (PlasmoDB), coccidians (ToxoDB), piroplasms (PiroplasmaDB), and Cryptosporidium species (CryptoDB). One possible target for drugs is the plastid, and in fact existing drugs such as tetracyclines, which are effective against apicomplexans, seem to operate against the plastid. Many Coccidiomorpha have an intermediate host, as well as a primary host, and the evolution of hosts proceeded in different ways and at different times in these groups. For some coccidiomorphs, the original host has become the intermediate host, whereas in others it has become the definitive host. In the genera Aggregata, Atoxoplasma, Cystoisospora, Schellackia, and Toxoplasma, the original is now definitive, whereas in Akiba, Babesiosoma, Babesia, Haemogregarina, Haemoproteus, Hepatozoon, Karyolysus, Leucocytozoon, Plasmodium, Sarcocystis, and Theileria, the original hosts are now intermediate. Similar strategies to increase the likelihood of transmission have evolved in multiple genera. Polyenergid oocysts and tissue cysts are found in representatives of the orders Protococcidiorida and Eimeriida. Hypnozoites are found in Karyolysus lacerate and most species of Plasmodium; transovarial transmission of parasites occurs in lifecycles of Karyolysus and Babesia. Horizontal gene transfer appears to have occurred early on in this phylum's evolution with the transfer of a histone H4 lysine 20 (H4K20) modifier, KMT5A (Set8), from an animal host to the ancestor of apicomplexans. A second gene—H3K36 methyltransferase (Ashr3 in plants)—may have also been horizontally transferred.
Apicomplexa	Blood-borne genera	Blood-borne genera Within the Apicomplexa are three suborders of parasites: suborder Adeleorina—eight genera suborder Laveraniina (formerly Haemosporina)—all genera in this suborder suborder Eimeriorina—two genera (Lankesterella and Schellackia) Within the Adelorina are species that infect invertebrates and others that infect vertebrates. The Eimeriorina—the largest suborder in this phylum—the lifecycle involves both sexual and asexual stages. The asexual stages reproduce by schizogony. The male gametocyte produces a large number of gametes and the zygote gives rise to an oocyst, which is the infective stage. The majority are monoxenous (infect one host only), but a few are heteroxenous (lifecycle involves two or more hosts). The number of families in this later suborder is debated, with the number of families being between one and 20 depending on the authority and the number of genera being between 19 and 25.
Apicomplexa	Taxonomy	Taxonomy
Apicomplexa	History	History The first Apicomplexa protozoan was seen by Antonie van Leeuwenhoek, who in 1674 saw probably oocysts of Eimeria stiedae in the gall bladder of a rabbit. The first species of the phylum to be described, Gregarina ovata, in earwigs' intestines, was named by Dufour in 1828. He thought that they were a peculiar group related to the trematodes, at that time included in Vermes. Since then, many more have been identified and named. During 1826–1850, 41 species and six genera of Apicomplexa were named. In 1951–1975, 1873 new species and 83 new genera were added. The older taxon Sporozoa, included in Protozoa, was created by Leuckart in 1879 and adopted by Bütschli in 1880.Bütschli, O. (1880-82). Dr. H.G. Bronn's Klassen und Ordnungen des Thier-Reichs. Erster Band: Protozoa. Abt. I, Sarkodina und Sporozoa, . Through history, it grouped with the current Apicomplexa many unrelated groups. For example, Kudo (1954) included in the Sporozoa species of the Ascetosporea (Rhizaria), Microsporidia (Fungi), Myxozoa (Animalia), and Helicosporidium (Chlorophyta), while Zierdt (1978) included the genus Blastocystis (Stramenopiles). Dermocystidium was also thought to be sporozoan. Not all of these groups had spores, but all were parasitic. However, other parasitic or symbiotic unicellular organisms were included too in protozoan groups outside Sporozoa (Flagellata, Ciliophora and Sarcodina), if they had flagella (e.g., many Kinetoplastida, Retortamonadida, Diplomonadida, Trichomonadida, Hypermastigida), cilia (e.g., Balantidium) or pseudopods (e.g., Entamoeba, Acanthamoeba, Naegleria). If they had cell walls, they also could be included in plant kingdom between bacteria or yeasts. Sporozoa is no longer regarded as biologically valid and its use is discouraged, although some authors still use it as a synonym for the Apicomplexa. More recently, other groups were excluded from Apicomplexa, e.g., Perkinsus and Colpodella (now in Protalveolata). The field of classifying Apicomplexa is in flux and classification has changed throughout the years since it was formally named in 1970. By 1987, a comprehensive survey of the phylum was completed: in all, 4516 species and 339 genera had been named. They consisted of: Class Conoidasida Subclass Gregarinasina p.p. Order Eugregarinorida, with 1624 named species and 231 named genera Subclass Coccidiasina p.p Order Eucoccidiorida p.p Suborder Adeleorina p.p Group Hemogregarines, with 399 species and four genera Suborder Eimeriorina, with 1771 species and 43 genera Class Aconoidasida Order Haemospororida, with 444 species and nine genera Order Piroplasmorida, with 173 species and 20 genera Other minor groups omitted above, with 105 species and 32 genera Although considerable revision of this phylum has been done (the order Haemosporidia now has 17 genera rather than 9), these numbers are probably still approximately correct.
Apicomplexa	Jacques Euzéby (1988)	Jacques Euzéby (1988) Jacques Euzéby in 1988 created a new class Haemosporidiasina by merging subclass Piroplasmasina and suborder Haemospororina. Subclass Gregarinasina (the gregarines) Subclass Coccidiasina Suborder Adeleorina (the adeleorins) Suborder Eimeriorina (the eimeriorins) Subclass Haemosporidiasina Order Achromatorida Order Chromatorida The division into Achromatorida and Chromatorida, although proposed on morphological grounds, may have a biological basis, as the ability to store haemozoin appears to have evolved only once.
Apicomplexa	Roberts and Janovy (1996)	Roberts and Janovy (1996) Roberts and Janovy in 1996 divided the phylum into the following subclasses and suborders (omitting classes and orders): Subclass Gregarinasina (the gregarines) Subclass Coccidiasina Suborder Adeleorina (the adeleorins) Suborder Eimeriorina (the eimeriorins) Suborder Haemospororina (the haemospororins) Subclass Piroplasmasina (the piroplasms) These form the following five taxonomic groups: The gregarines are, in general, one-host parasites of invertebrates. The adeleorins are one-host parasites of invertebrates or vertebrates, or two-host parasites that alternately infect haematophagous (blood-feeding) invertebrates and the blood of vertebrates. The eimeriorins are a diverse group that includes one host species of invertebrates, two-host species of invertebrates, one-host species of vertebrates and two-host species of vertebrates. The eimeriorins are frequently called the coccidia. This term is often used to include the adeleorins. Haemospororins, often known as the malaria parasites, are two-host Apicomplexa that parasitize blood-feeding dipteran flies and the blood of various tetrapod vertebrates. Piroplasms where all the species included are two-host parasites infecting ticks and vertebrates.
Apicomplexa	Perkins (2000)	Perkins (2000) thumb\|right\|300px Perkins et al. proposed the following scheme. It is outdated as the Perkinsidae have since been recognised as a sister group to the dinoflagellates rather that the Apicomplexia: Class Aconoidasida Conoid present only in the ookinete of some species Order Haemospororida Macrogamete and microgamete develop separately. Syzygy does not occur. Ookinete has a conoid. Sporozoites have three walls. Heteroxenous: alternates between vertebrate host (in which merogony occurs) and invertebrate host (in which sporogony occurs). Usually blood parasites, transmitted by blood-sucking insects. Order Piroplasmorida Class Conoidasida Subclass Gregarinasina Order Archigregarinorida Order Eugregarinorida Suborder Adeleorina Suborder Eimeriorina Order Neogregarinorida Subclass Coccidiasina Order Agamococcidiorida Order Eucoccidiorida Order Ixorheorida Order Protococcidiorida Class Perkinsasida Order Perkinsorida Family Perkinsidae The name Protospiromonadida has been proposed for the common ancestor of the Gregarinomorpha and Coccidiomorpha. Another group of organisms that belong in this taxon are the corallicolids. These are found in coral reef gastric cavities. Their relationship to the others in this phylum has yet to be established. Another genus has been identified - Nephromyces - which appears to be a sister taxon to the Hematozoa.Muñoz-Gómez SA, Durnin K, Eme L, Paight C, Lane CE, Saffo MB, Slamovits CH (2019) Nephromyces represents a diverse and novel lineage of the Apicomplexa that has retained apicoplasts. Genome Biol Evol This genus is found in the renal sac of molgulid ascidian tunicates.
Apicomplexa	Evolution	Evolution Members of this phylum, except for the photosynthetic chromerids, are parasitic and evolved from a free-living ancestor. This lifestyle is presumed to have evolved at the time of the divergence of dinoflagellates and apicomplexans. Further evolution of this phylum has been estimated to have occurred about . The oldest extant clade is thought to be the archigregarines. These phylogenetic relations have rarely been studied at the subclass level. The Haemosporidia are related to the gregarines, and the piroplasms and coccidians are sister groups. The Haemosporidia and the Piroplasma appear to be sister clades, and are more closely related to the coccidians than to the gregarines. Marosporida is a sister group to Coccidiomorphea. Janouškovec et al. 2015 presents a somewhat different phylogeny, supporting the work of others showing multiple events of plastids losing photosynthesis. More importantly this work provides the first phylogenetic evidence that there have also been multiple events of plastids becoming genome-free.
Apicomplexa	See also	See also Centrocone

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