A close look at the inner workings of the spoiler during the landing of an Airbus A320.

A close look at the spoiler (the parts of the wing that are raised up) during the landing of an Airbus A321.

In aeronautics, a spoiler (sometimes called a lift dumper) is a device intended to reduce lift in an aircraft. Spoilers are plates on the top surface of a wing which can be extended upward into the airflow and spoil it. By doing so, the spoiler creates a carefully controlled stall over the portion of the wing behind it, greatly reducing the lift of that wing section. Spoilers differ from airbrakes in that airbrakes are designed to increase drag making little change to lift, while spoilers greatly reduce lift making only a moderate increase in drag.

Spoilers are used by some older gliders to control their rate of descent and thus achieve a controlled landing at a desired spot. An increased rate of descent could also be achieved by lowering the nose of an aircraft, but this would result in an excessive landing speed. However spoilers enable the approach to be made at a safe speed for landing.

Airliners too are usually fitted with spoilers. Spoilers are sometimes used when descending from cruise altitudes to assist the aircraft in descending to lower altitudes without picking up speed. Their use is often limited, however, as turbulent airflow which develops behind them causes noticeable noise and vibration, which may cause discomfort to extra-sensitive passengers. The spoilers may also be differentially operated to provide roll control. Martin Aircraft was the first to develop spoilers to help with roll control in 1948. ^[1] On landing, however, the spoilers are nearly always used at full effect to assist in slowing the aircraft. The increase in form drag created by the spoilers directly assists the braking effect. However, the real gain comes as the spoilers cause a dramatic loss of lift and hence the weight of the aircraft is transferred from the wings to the undercarriage, allowing the wheels to be mechanically braked with much less chance of skidding. Reverse thrust is also often further used to help slow the aircraft on landing.

In air-cooled piston engine aircraft, spoilers may be needed to avoid shock cooling the engines. In a descent without spoilers, air speed is increased and the engine will be at low power, producing less heat than normal. The engine may cool too rapidly, resulting in stuck valves, cracked cylinders or other problems. Spoilers alleviate the situation by allowing the aircraft to descend at a desired rate while letting the engine run at a power setting that keeps it from cooling too quickly. (This is particularly true in turbocharged piston engines, which generate higher temperatures than normally aspirated engines.)

Spoilers as control surfaces[link]

Some aircraft use spoilers in combination with or in lieu of ailerons for roll control, primarily to reduce adverse yaw when rudder input is limited by higher speeds. For such spoilers the term spoileron has been coined. In the case of a spoileron, in order for it to be used as a control surface, it is raised on one wing, thus decreasing lift and increasing drag, causing roll and yaw.

Spoilers, general description[link]

Spoilers increase drag and reduce lift on the wing. If raised on only one wing, they aid roll control, causing that wing to drop. If the spoilers raise symmetrically in flight, the aircraft can either be slowed in level flight or can descend rapidly without an increase in airspeed. When the spoilers rise on the ground at high speeds, they reduce the wing's lift, which puts more of the aircraft's weight on the wheels.

The flight spoilers are available both in flight and on the ground. However, the ground spoilers can only be raised when the weight of the aircraft is on the landing gear, usually activated by a sensor. When the spoilers deploy on the ground, they decrease lift and make the brakes more effective. In flight, a ground-sensing switch on the landing gear prevents deployment of the ground spoilers.

Incidents and accidents[link]

• Air Canada Flight 621 – Premature deployment of the spoilers at low altitude contributed to this crash in Toronto on 5 July 1970.

• United Airlines Flight 553 – Forgetting to deactivate the spoilers contributed to this crash at Chicago Midway International Airport on 8 December 1972.

• American Airlines Flight 965 – Forgetting to deactivate the spoilers while climbing to avoid a mountain contributed to this crash on 20 December 1995.

• American Airlines Flight 1420 – Forgetting to deploy the spoilers contributed to this crash at Little Rock National Airport on 1 June 1999.

• TAM Brazilian Airlines Flight 3054 – This Airbus 320's pilots were aware of their deactivated starboard engine #2 thrust reverser,^[2] and so apparently did not attempt to use it to brake when attempting to land at São Paulo's Congonhas Airport on 17 July 2007. The plane's spoilers may have been their only method of braking at speed. The plane slid off the runway, over a major highway, and ploughed into a warehouse, killing all 186 on board as well as several on the ground. It was Brazil's worst aviation disaster.^[3]

See also[link]

• Air brake (aircraft)

References[link]

Wikimedia Commons has media related to: Spoilers (aircraft wings)

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (January 2009)

Look up spoiler in Wiktionary, the free dictionary.

Spoiler may refer to:

• Spoiler (aeronautics), a device to reduce lift in aeronautics
• Spoiler (automotive), a device to modify air flow in order to increase fuel efficiency or improve handling in automobiles
• Spoiler (sports), a team that has been eliminated from the playoffs, and beats a team that required that win to advance
• Spoiler (media), a comment which discloses plot details of a book, play, video game, or film, or is intended to distract attention from a rival
• Spoiler (comics), a secondary character in the DC comic book Robin
• Spoiler (film), a comedy film project in New York City
• Spoiler effect, an individual unable to win an election or game for him- or herself, but with the power to determine which player among two or more others will win
• Mighty Spoiler, a popular calypso singer
• Don Jardine, a professional wrestler also known as "the Spoiler"
• The Spoiler (album) a 1966 album by jazz saxophonist Stanley Turrentine

This disambiguation page lists articles associated with the same title. If an internal link led you here, you may wish to change the link to point directly to the intended article.

Space Shuttle Atlantis on a Shuttle Carrier Aircraft.

Aeronautics (from Greek ὰήρ āēr which means "air" and ναυτική nautikē which means "navigation, Airmanship", i.e. "navigation of the air") is the science involved with the study, design, and manufacturing of airflight-capable machines, or the techniques of operating aircraft and rocketry within the atmosphere. While the term—literally meaning "sailing the air"—originally referred solely to the science of operating the aircraft,it has since been expanded to include technology, business and other aspects related to aircraft.^[1]

One of the significant parts in aeronautics is a branch of physical science called aerodynamics, which deals with the motion of air and the way that it interacts with objects in motion, such as an aircraft. The term "aviation" is sometimes used interchangeably with aeronautics, although "aeronautics" includes lighter-than-air craft such as airships, and includes ballistic vehicles while "aviation" does not.^[1]

Early aeronautics[link]

Francesco Lana de Terzi's flying boat concept c.1670.

The first mention of aeronautics in history was in the writings of ancient Egyptians who described the flight of birds. It also finds mention in ancient China where people were flying kites thousands of years ago. The medieval Islamic scientists were not far behind, as they understood the actual mechanism of bird flight. Before scientific investigation of aeronautics started, people started thinking of ways to fly. In a Greek legend, Icarus and his father Daedalus built wings of feathers and wax and flew out of a prison. Icarus flew too close to the sun, the wax melted, and he fell in the sea and drowned. When people started to scientifically study how to fly, people began to understand the basics of air and aerodynamics. Ibn Firnas may have tried to fly in 8th century in Cordoba, Al-Andalus.^[2]

Roger Bacon and Leonardo da Vinci were some of the first modern Europeans to study aeronautics. Leonardo studied the flight of birds in developing engineering schematics for some of the earliest flying machines in the late fifteenth century AD. His schematics, however, such as the Ornithopter ultimately failed as practical aircraft. The flapping machines that he designed were either too small to generate sufficient lift, or too heavy for a human to operate.

Although the ornithopter continues to be of interest to hobbyists, it was replaced by the glider in the 19th century. Sir George Cayley was one of the most important people in the history of aeronautics. Many consider him the first true scientific aerial investigator and the first person to understand the underlying principles and forces of flight.^[3] A pioneer of aeronautical engineering,^[4] he is credited as the first person to separate the forces of lift and drag which are in effect on any flight vehicle,^[5]

Francesco Lana de Terzi, a 17th century Jesuit professor of physics and mathematics from Brescia, Lombardy, has been referred to as the Father of Aeronautics.^[6] In his work Prodromo dell'Arte Maestra (1670) he proposes a lighter-than-air vessel based on logical deductions from previous work ranging from Archimedes and Euclid to his contemporaries Robert Boyle and Otto von Guericke.

Early aviation research[link]

Many cultures have built devices that travel through the air, from the earliest projectiles such as stones and spears,^[7][8] the boomerang in Australia, the hot air Kongming lantern, and kites. There are early legends of human flight such as the story of Icarus, and Jamshid in Persian myth, and later, somewhat more credible claims of short-distance human flights appear, such as the flying automaton of Archytas of Tarentum (428–347 BC),^[9] the winged flights of Abbas Ibn Firnas (810–887), Eilmer of Malmesbury (11th century), and the hot-air Passarola of Bartolomeu Lourenço de Gusmão (1685–1724).

The modern age of aviation began with the first untethered human lighter-than-air flight on November 21, 1783, in a hot air balloon designed by the Montgolfier brothers. The practicality of balloons was limited because they could only be controlled vertically. It was immediately recognized that a steerable, or dirigible, balloon was required. Jean-Pierre Blanchard flew the first human-powered dirigible in 1784 and crossed the English Channel in one in 1785.

In 1799 Sir George Cayley set forth the concept of the modern airplane as a fixed-wing flying machine with separate systems for lift, propulsion, and control.^[4][10] Early dirigible developments included machine-powered propulsion (Henri Giffard, 1852), rigid frames (David Schwarz, 1896), and improved speed and maneuverability (Alberto Santos-Dumont, 1901)

Early aviation[link]

First assisted take-off flight by the Wright Brothers, December 17, 1903

While there are many competing claims for the earliest powered, heavier-than-air flight, the most widely-accepted date is December 17, 1903 by the Wright brothers. The Wright brothers were the first to fly in a powered and controlled aircraft. Previous flights were gliders (control but no power) or free flight (power but no control), but the Wright brothers combined both, setting the new standard in aviation records. Following this, the widespread adoption of ailerons versus wing warping made aircraft much easier to control, and only a decade later, at the start of World War I, heavier-than-air powered aircraft had become practical for reconnaissance, artillery spotting, and even attacks against ground positions.

Aircraft began to transport people and cargo as designs grew larger and more reliable. In contrast to small non-rigid blimps, giant rigid airships became the first aircraft to transport passengers and cargo over great distances. The best known aircraft of this type were manufactured by the German Zeppelin company.

Hindenburg at Lakehurst Naval Air Station, 1936

The most successful Zeppelin was the Graf Zeppelin. It flew over one million miles, including an around-the-world flight in August 1929. However, the dominance of the Zeppelins over the aeroplanes of that period, which had a range of only a few hundred miles, was diminishing as aeroplane design advanced. The "Golden Age" of the airships ended on May 6, 1937 when the Hindenburg caught fire, killing 36 people. Although there have been periodic initiatives to revive their use, airships have seen only niche application since that time.

Great progress was made in the field of aviation during the 1920s and 1930s, such as Charles Lindbergh's solo transatlantic flight in 1927, and Charles Kingsford Smith's transpacific flight the following year. One of the most successful designs of this period was the Douglas DC-3, which became the first airliner that was profitable carrying passengers exclusively, starting the modern era of passenger airline service. By the beginning of World War II, many towns and cities had built space, and there were numerous qualified pilots available. The war brought many innovations to aviation, including the first jet aircraft and the first liquid-fueled rockets.

Modern aviation[link]

NASA's Helios researches solar powered flight.

After World War II, especially in North America, there was a boom in general aviation, both private and commercial, as thousands of pilots were released from military service and many inexpensive war-surplus transport and training aircraft became available. Manufacturers such as Cessna, Piper, and Beechcraft expanded production to provide light aircraft for the new middle-class market.

By the 1950s, the development of civil jets grew, beginning with the de Havilland Comet, though the first widely-used passenger jet was the Boeing 707, because it was much more economical than other planes at the time. At the same time, turboprop propulsion began to appear for smaller commuter planes, making it possible to serve small-volume routes in a much wider range of weather conditions.

Since the 1960s, composite airframes and quieter, more efficient engines have become available, and Concorde provided supersonic passenger service for more than two decades, but the most important lasting innovations have taken place in instrumentation and control. The arrival of solid-state electronics, the Global Positioning System, satellite communications, and increasingly small and powerful computers and LED displays, have dramatically changed the cockpits of airliners and, increasingly, of smaller aircraft as well. Pilots can navigate much more accurately and view terrain, obstructions, and other nearby aircraft on a map or through synthetic vision, even at night or in low visibility.

On June 21, 2004, Space Ship One became the first privately funded aircraft to make a spaceflight, opening the possibility of an aviation market capable of leaving the Earth's atmosphere. Meanwhile, flying prototypes of aircraft powered by alternative fuels, such as ethanol, electricity, and even solar energy, are becoming more common and may soon enter the mainstream, at least for light aircraft.

Rocketry[link]

Launch of Apollo 15 Saturn V rocket: T - 30 s through T + 40 s.

A rocket or rocket vehicle is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use.^[11] Rocket engines work by action and reaction. Rocket engines push rockets forwards simply by throwing their exhaust backwards extremely fast.

Rockets for military and recreational uses date back to at least 13th century China.^[12] Significant scientific, interplanetary and industrial use did not occur until the 20th century, when rocketry was the enabling technology of the Space Age, including setting foot on the moon.

Rockets are used for fireworks, weaponry, ejection seats, launch vehicles for artificial satellites, human spaceflight and exploration of other planets. While comparatively inefficient for low speed use, they are very lightweight and powerful, capable of generating large accelerations and of attaining extremely high speeds with reasonable efficiency.

Chemical rockets are the most common type of rocket and they typically create their exhaust by the combustion of rocket propellant. Chemical rockets store a large amount of energy in an easily released form, and can be very dangerous. However, careful design, testing, construction and use minimizes risks.

See also[link]

The Eurofighter Typhoon.

Antonov An-225, the largest aeroplane ever built.

References[link]

External links[link]

Wikisource has the text of the 1911 Encyclopædia Britannica article Aeronautics.

Wikiquote has a collection of quotations related to: Aeronautics

Look up aeronautics in Wiktionary, the free dictionary.

• Smithsonian National Air and Space Museum's How Things Fly website
• Aeronautics History in Turkey
• Aeronautics History - Charles Vivian - 1920 (eLibrary Project - eLib full text)
• Aerospace courses at MIT OpenCourseWare
• American Academy of Aeronautics aeronautical science
• American Helicopter Society
• American Institute of Aeronautics and Astronautics
• Examples of Aeronautic Designs
• What is aeronautics? The history of world Aeronautics (Russian)
• Aircraft Design: Synthesis and Analysis
• ACARE Taxonomy
• CREating innovative Air transport Technologies for Europe