Air travel is a form of

travel Travel is the movement of people between distant geographical Location (geography), locations. Travel can be done by Pedestrian, foot, bicycle, automobile, train, boat, bus, airplane, ship or other means, with or without Baggage, luggage, a ...

in vehicles such as

airplane An airplane (American English), or aeroplane (Commonwealth English), informally plane, is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, Propeller (aircraft), propeller, or rocket engine. Airplanes come in a vari ...

jet aircraft A jet aircraft (or simply jet) is an aircraft (nearly always a fixed-wing aircraft) propelled by one or more jet engines. Whereas the engines in Propeller (aircraft), propeller-powered aircraft generally achieve their maximum efficiency at much ...

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

hot air balloon A hot air balloon is a lighter-than-air aircraft consisting of a bag, called an envelope, which contains heated air. Suspended beneath is a gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule), which carri ...

blimp A non-rigid airship, commonly called a blimp (Help:IPA/English, /blɪmp/), is an airship (dirigible) without an internal structural framework or a keel. Unlike semi-rigid airship, semi-rigid and rigid airships (e.g. Zeppelins), blimps rely on th ...

s, gliders, hang gliders, parachutes, or anything else that can sustain

flight Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...

."Aviation."Encyclopædia Britannica
Accessed June 2011. Use of air travel began vastly increasing in the 1930s: the number of Americans flying went from about 6,000 in 1930 to 450,000 by 1934 and to 1.2 million by 1938. It has continued to greatly increase in recent decades, doubling worldwide between the mid-1980s and the year 2000. Modern air travel is much safer than road travel.

Domestic and international flights

Air travel are separated into two general classifications: national/domestic and

international flight An international flight is a form of commercial flight within civil aviation where the Takeoff, departure and the arrival take place in different Country, countries. Regular international passenger air service began in August 1919 with a flight ...

s. Flights from one point to another within the same country are domestic flights. Flights from a point in one country to a point within a different country are international flights. Travelers can use domestic or international flights in either private or public travel.

Commercial air travel

Travel class A travel class is a quality of accommodation on public transport. The accommodation could be a seat or a cabin for example. Higher travel classes are designed to be more comfortable and are typically more expensive. Airlines Traditionally ...

on an airplane is usually split into a two, three or four class model service. U.S. domestic flights usually have two classes: economy class and a domestic first class partitioned into cabins. International flights may have up to four classes: economy class; premium economy; business class or club class; and first class. Most air travel starts and ends at a commercial

airport An airport is an aerodrome with extended facilities, mostly for commercial Aviation, air transport. They usually consist of a landing area, which comprises an aerially accessible open space including at least one operationally active surf ...

. The typical procedure is

check-in Check-in is the process whereby people announce their arrival at an office, hotel, airport, hospital, port, seaport or event. Office check-in Many offices have a reception or front office area near the entrance to greet or assist visitors arriv ...

;

border control Border control comprises measures taken by governments to monitor and regulate the movement of people, animals, and goods across land, air, and maritime borders. While border control is typically associated with international borders, it als ...

;

airport security Airport security includes the techniques and methods used in an attempt to protect passengers, staff, aircraft, and airport property from malicious harm, crime, terrorism, and other threats. Aviation security is a combination of measures and hum ...

baggage and passenger check before entering the gate; boarding; flying; and pick-up of luggage and – limited to international flights – another border control at the host country's

border Borders are generally defined as geography, geographical boundaries, imposed either by features such as oceans and terrain, or by polity, political entities such as governments, sovereign states, federated states, and other administrative divisio ...

. Most passengers must go through these steps when flying with a commercial airline. For longer journeys, air travel may consist of several flights with a

layover 250px, Layover for buses at LACMTA's Los_Angeles.html" ;"title="Warner Center Transit Hub, Los Angeles">Warner Center Transit Hub, Los Angeles In scheduled transportation, a layover (also way station, or connection) is a point where a vehic ...

in between. The number of layovers often depends on the number of hub airports the journey is routed through. Airlines rely either on the point-to-point model or the spoke-and-hub model to operate flights in between airports. The point-to-point model, often used by low-cost carriers such as Southwest, relies on scheduling flights directly between destination airports. The spoke-and-hub model, used by carriers such as American and Delta, relies on scheduling flights to and from hub airports. The hub-and-spoke model allows airlines to connect more destinations and provide more frequent routes, while the point-to-point system allows airlines to avoid layovers and have more cost effective operations.

Environmental effects

Modern aircraft consume less fuel per person and mile traveled than cars when fully booked. However, the distances traveled are often significantly larger and will not replace car travel but instead add to it, and not every flight is booked out. Instead, the scheduled flights are predominant, resulting in a far worse

fuel efficiency Fuel efficiency (or fuel economy) is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical energy, chemical potential energy contained in a carrier (fuel) into kinetic energy or Mechanical work, w ...

. According to the ATAG, flights produced of the

greenhouse gas Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...

in 2015 globally, as compared to an estimated total of anthropogenic .

Carbon offset Carbon offsetting is a carbon trading mechanism that enables entities to compensate for offset greenhouse gas emissions by investing in projects that reduce, avoid, or remove emissions elsewhere. When an entity invests in a carbon offsetting ...

is often proposed as solution to mitigate the emissions of flying. There are many NGOs that offer to compensate emissions by advancing clean renewable energy, reducing energy consumption and capturing already released carbon in trees or other plants. However, carbon offsetting is a very controversial topic as it only tries to mitigate what has already been emitted.

Safety

Modern air travel is significantly safer than road travel. In 2008 in the United States, there were 1.27 fatalities per 100 million road vehicle miles, compared to no fatalities and almost zero accidents per million flying miles. There were more than five million driving accidents, compared to 20 accidents in flying. Travelers may perceive planes to be more dangerous as they do not allow individual control and because plane crashes are more catastrophic events (the availability bias).

Health effects

Deep vein thrombosis (DVT) is the third-most common vascular disease, next to stroke and heart attack. It is estimated that DVT affects one in 5,000 travelers on long flights. Risk increases with exposure to more flights within a short time frame and with increasing duration of flights. During flight, the aircraft cabin pressure is usually maintained at the equivalent of above sea level. Most healthy travelers will not notice any effects. However, for travelers with cardiopulmonary diseases (especially those who normally require supplemental oxygen), cerebrovascular disease, anemia, or sickle cell disease, conditions in an aircraft can exacerbate underlying medical conditions. Aircraft cabin air is typically dry, usually 10%–20% humidity, which can cause dryness of the mucous membranes of the eyes and airways.

References

External links

{{Authority control Types of travel Civil aviation