Sunset or sundown is the daily disappearance of the Sun below the horizon, as a result of Earth’s rotation.
The time of sunset is defined in astronomy as the moment when the trailing edge of the Sun’s disk disappears below the horizon. The ray path of light from the setting Sun is highly distorted near the horizon because of atmospheric refraction, making the sunset appear to occur when the Sun’s disk is already about one diameter below the horizon. Sunset is distinct from dusk, which is the time at which the sky becomes completely dark, which occurs when the Sun is approximately eighteen degrees below the horizon. The period between sunset and dusk is called twilight.
Locations north of the Arctic Circle and south of the Antarctic Circle experience no sunset or sunrise at least one day of the year, when the polar day or the polar night persists continuously for 24 hours.
Sunset creates unique atmospheric conditions such as the often intense orange and red colors of the Sun and the surrounding sky.
Um avião ou aeroplano é qualquer aeronave que necessita de asas fixas e motores para se sustentar no ar. Pode possuir um ou mais planos de asa, sendo estas fixas em relação ao corpo da aeronave, ou seja, que dependem do movimento do veículo como um todo para gerar sustentação aérea. Essa definição de asa fixa também se aplica aos que possuem asas dobráveis pois estas também só geram sustentação ao se deslocar todo o veículo.
The Airbus A319 is a member of the Airbus A320 family of short- to medium-range, narrow-body, commercial passenger twin-engine jet airliners manufactured by Airbus. The A319 carries up to 160 passengers and has a maximum range of 3,700 nmi (6,900 km; 4,300 mi). Final assembly of the aircraft takes place in Hamburg, Germany and Tianjin, China.
The A319 is a shortened-fuselage variant of the Airbus A320 and entered service in April 1996 with Swissair, around two years after the stretched Airbus A321 and eight years after the original A320. The aircraft shares a common type rating with all other Airbus A320 family variants, allowing existing A320 family pilots to fly the aircraft without the need for further training.
As of February 2018, a total of 1,469 Airbus A319 aircraft have been delivered, of which 1,448 are in service. In addition, another 45 airliners are on firm order (comprising 15 A319ceo and 30 A319neo). As of 28 February 2018, EasyJet was the largest operator of the Airbus A319, operating 137 aircraft.
The Airbus A320 family consists of short- to medium-range, narrow-body, commercial passenger twin-engine jet airliners manufactured by Airbus. The family includes the A318, A319, A320 and A321, as well as the ACJ business jet. The A320s are also named A320ceo (current engine option) after the introduction of the A320neo (new engine option). Final assembly of the family takes place in Toulouse, France, and Hamburg, Germany. A plant in Tianjin, China, has also been producing aircraft for Chinese airlines since 2009, while a final assembly facility in Mobile, Alabama, United States, delivered its first A321 in April 2016. The aircraft family can accommodate up to 236 passengers and has a range of 3,100 to 12,000 km (1,700 to 6,500 nmi), depending on model.
The first member of the A320 family—the A320—was launched in March 1984, first flew on 22 February 1987, and was first delivered in March 1988 to launch customer Air France. The family was extended to include the A321 (first delivered 1994), the A319 (1996), and the A318 (2003). The A320 family pioneered the use of digital fly-by-wire flight control systems, as well as side-stick controls, in commercial aircraft. There has been a continuous improvement process since introduction.
The Airbus A321 is a member of the Airbus A320 family of short- to medium-range, narrow-body, commercial passenger twin-engine jet airliners manufactured by Airbus. It was the first derivative of the baseline Airbus A320 aircraft, and carries up to 236 passengers with a maximum range of 3,200 nmi (5,900 km; 3,700 mi). Final assembly of the aircraft takes place in Hamburg, Germany, or Mobile, Alabama.
The A321 is a stretched-fuselage variant of the Airbus A320 and entered service in 1994 with Lufthansa, around six years after the original A320. The aircraft shares a common type rating with all other Airbus A320 family variants, allowing existing A320 family pilots to fly the aircraft without the need for further training.
In December 2010, Airbus announced a new generation of the A320 family, the A320neo (new engine option). The similarly lengthened fuselage A321neo variant offers new, more efficient engines, combined with airframe improvements and the addition of winglets, named Sharklets by Airbus. The aircraft will deliver fuel savings of up to 15%.