Hangar in the context of "Folding wing"

An airport is an aerodrome with extended facilities, mostly for commercial air transport. They usually consist of a landing area, which comprises an aerially accessible open space including at least one operationally active surface such as a runway for a plane to take off and to land or a helipad, and often includes adjacent utility buildings such as control towers, hangars and terminals, to maintain and monitor aircraft. Larger airports may have airport aprons, taxiway bridges, air traffic control centres, passenger facilities such as restaurants and lounges, and emergency services. In some countries, the US in particular, airports also typically have one or more fixed-base operators, serving general aviation.

Airport operations are extremely complex, with a complicated system of aircraft support services, passenger services, and aircraft control services contained within the operation. Thus airports can be major employers, as well as important hubs for tourism and other kinds of transit. Because they are sites of operation for heavy machinery, a number of regulations and safety measures have been implemented in airports, in order to reduce hazards. Additionally, airports have major local environmental impacts, as both large sources of air pollution, noise pollution and other environmental impacts, making them sites that acutely experience the environmental effects of aviation. Airports are also vulnerable infrastructure to extreme weather, climate change caused sea level rise and other disasters.

Naval aviation is the application of military air power by navies, either from warships that can embark aircraft (e.g. aircraft carriers, amphibious assault ships and aircraft cruisers) or from coastal naval air stations.It often involves navalised aircraft, specifically designed for naval use.Seaborne aviation encompasses similar activities not restricted to navies, including marines and coast guards, such as in U.S. naval aviators. As with most army aviation units, naval aviation units are generally separate from a nation's dedicated air force.

Naval aviation operations are typically projected by way of carrier-based aircraft, which must be sturdy enough to withstand the demands of shipborne operations at sea. They must be able to take off from a short runway (typically the flight deck of an aircraft carrier) and be sturdy and flexible enough to come to a sudden stop when landing; they typically have robust folding or swinging wings that reduce the occupied space and thus allow more of them to be stored in below-decks hangars and limited parking spaces on flight decks. These aircraft are designed for many tactical purposes, including aerial combat, airstrike/close air support, anti-submarine warfare, early warning, search and rescue, matériel transport, weather observation, patrol and reconnaissance, and wide-area command and control duties.

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 do not often land 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.

This is a list of aircraft carriers which are currently in service, under maintenance or refit, in reserve, under construction, or being updated. An aircraft carrier is a warship with a full-length flight deck, hangar and facilities for arming, deploying, and recovering aircraft. The list only refers to the status of the ship, not availability or condition of an air wing. This includes helicopter carriers and also amphibious assault ships, if the vessel's primary purpose is to carry, arm, deploy, and recover aircraft.

A corvette is a small warship. It is traditionally the smallest class of vessel considered to be a proper (or "rated") warship. The warship class above the corvette is that of the frigate, while the class below was historically that of the sloop-of-war.

The modern roles that a corvette fulfills include coastal patrol craft, missile boat and fast attack craft. These corvettes are typically between 500 and 2,000 tons. Recent designs of corvettes may approach 3,000 tons and include a hangar to accommodate a helicopter, having size and capabilities that overlap with smaller frigates. However unlike contemporary frigates, a modern corvette does not have sufficient endurance or seaworthiness for long voyages.

A helicopter carrier is a type of aircraft carrier whose primary purpose is to operate helicopters. It has a large flight deck that occupies a substantial part of the deck, which can extend the full length of the ship like HMS Ocean of the Royal Navy (RN), or extend only partway, usually aft, as in the Soviet Navy's Moskva class or in the Chinese Navy's Type 0891A. It often also has a hangar deck for the storage and maintenance of rotorwing aircraft.

Pure helicopter carriers are difficult to define in the 21st century. The advent of STOVL aircraft such as the Harrier jump jet, and now the F-35B, have complicated the classification; the United States Navy's Wasp class, for instance, carries six to eight Harriers as well as over 20 helicopters. Only smaller carriers unable to operate the Harrier, and older, pre-Harrier-era carriers, can be regarded as true helicopter carriers. In many cases, other carriers, able to operate STOVL aircraft, are classified as "light aircraft carriers". Other vessels, such as the Wasp class, are also capable of embarking troops such as marines and landing them ashore; they are classified as landing helicopter docks.

A taxiway is a path for aircraft at an airport connecting runways with aprons, hangars, terminals and other facilities. They mostly have a hard surface such as asphalt or concrete, although smaller general aviation airports sometimes use gravel or grass.

Most airports do not have a specific speed limit for taxiing (though some do). There is a general rule on safe speed based on obstacles. Operators and aircraft manufacturers might have limits. Typical taxi speeds are 20–30 kn (37–56 km/h; 23–35 mph).