Wednesday, December 31, 2008

Engine failure

Although aircraft are now designed to fly even after the failure of one or more aircraft engines, the failure of the second engine on one side for example is obviously serious. Losing all engine power is even more serious, as illustrated by the 1970 Dominican a DC-9 air disaster, when fuel contamination caused the failure of both engines. To have an emergency landing site is then very important.

In the 1983 Gimli Glider incident, an Air Canada flight suffered fuel exhaustion during cruise flight, forcing the pilot to glide the plane to an emergency dead stick landing. The automatic deployment of the ram air turbine maintained the necessary hydraulic pressure to the flight controls, so that the pilot was able to land with only a minimal amount of damage to the plane, and minor (evacuation) injuries to a few passengers.

The ultimate form of engine failure, physical separation, occurred in 1979 when a complete engine detached from American Airlines Flight 191, causing damage to the aircraft and loss of control.

Wednesday, December 24, 2008

Navigation aids and instrument flight

One of the first navigation aids to be introduced (in the USA in the late 1920s) was airfield lighting to assist pilots to make landings in poor weather or after dark. The Precision Approach Path Indicator was developed from this in the 1930s, indicating to the pilot the angle of descent to the airfield. This later became adopted internationally through the standards of the International Civil Aviation Organization (ICAO).

With the spread of radio technology, several experimental radio based navigation aids were developed from the late 1920s onwards. These were most successfully used in conjunction with instruments in the cockpit in the form of Instrument landing systems (ILS), first used by a scheduled flight to make a landing in a snowstorm at Pittsburgh in 1938. A form of ILS was adopted by the ICAO for international use in 1949.

Following the development of radar in World War II, it was deployed as a landing aid for civil aviation in the form of Ground-controlled approach (GCA) systems, joined in 1948 by distance measuring equipment (DME), and in the 1950s by airport surveillance radar as an aid to air traffic control. VHF omni directional range (VOR) became the predominate means of route navigation during the 1960s superseding the Non-directional beacon (NDB). The ground based VOR stations were often co-located with DME, so that pilots could know both their radials in degrees with respect to north to, and their slant range distance to, that beacon.

Wednesday, December 17, 2008

Air safety

Air safety is a term encompassing the theory, investigation and categorization of flight failures, and the prevention of such failures through regulation, education and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.
In most countries, civil aircraft have to be certified by the Civil Aviation Authority (CAA) to be allowed to fly. The major aviation authorities worldwide are the US Federal Aviation Administration (FAA) the European Aviation Safety Agency (EASA) (which provides regulatory advice to the European Union and to a degree supplanted the regulatory bodies of member countries). FAA and EASA are, in particular, primarily responsible for the certification of the airliners from the two major manufacturers, Boeing and Airbus.

Aircraft are certified against guidelines set out in the code for each CAA. Those codes are very similar and differ primarily in equipment and environmental standards. Regulations on maintenance, repair and operation provide further direction to the owners of the aircraft so that the aircraft continues to meet design standards.

Wednesday, December 10, 2008

Spacecraft

A spacecraft is a craft or machine designed for spaceflight. On a spaceflight, a spacecraft enters space then returns to the Earth. For an orbital spaceflight, a spacecraft enters a closed orbit around the planetary body. Spacecraft used for human spaceflights carry people on board as crew or passengers. Spacecraft used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft that leave the vicinity of the planetary body are space probes. Robotic spacecraft that remain in orbit around the planetary body are artificial satellites. Starships, which are built for interstellar travel, are so far a theoretical concept only.

Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and space tourism. Spacecraft and space travel are common themes in works of science fiction.

Wednesday, November 19, 2008

Early aeronautics

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. One of the earliest scientists to study aeronautics was Leonardo da Vinci.

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.

Wednesday, November 12, 2008

Cardiac Arrest

The heart has an internal electrical system that controls the rhythm of the heartbeat. Problems can cause abnormal heart rhythms, called arrhythmias. There are many types of arrhythmia. During an arrhythmia, the heart can beat too fast, too slow, or it can stop beating. Sudden cardiac arrest occurs when the heart develops an arrhythmia that causes it to stop beating. This is different than a heart attack, where the heart usually continues to beat but blood flow to the heart is blocked.

There are many possible causes of cardiac arrest. They include coronary heart disease, heart attack, electrocution, drowning, or choking. There may not be a known cause to the cardiac arrest.

Without medical attention, the person will die within a few minutes. People are less likely to die if they have early cardiopulmonary resuscitation (CPR) and defibrillation. Defibrillation is delivering an electric shock to restore the heart rhythm to normal.

Tuesday, November 04, 2008

Dogarutkay Flowers

A flower also recognized as a bloom or blossom, is the reproductive configuration establish in flowering plants. The flower's structure contains the plant's reproductive organs, and its role is to make seeds. After fertilization, portions of the flower build up into a fruit containing the seeds. For the high plants, seeds are the next production, and serve up as the primary means by which individuals of a variety are dispersed across the scenery. The grouping of flowers on a place is called the inflorescence.

Many flowers in natural world have evolved to magnetize animals to pollinate the flower, the actions of the pollinating means contributing to the chance for genetic recombination within a dispersed plant population. Flowers commonly have glands called nectarines on their various parts that attract these birds.

Wednesday, October 15, 2008

Astronautics

Astronautics, or Astronautical Engineering, is the branch of engineering that deal with machines designed to exit or work entirely beyond the Earth's atmosphere. In other words, it is the science and skill of space flight.

The term Astronautics was coin by analogy with Aeronautics. As there is a certain degree of skill overlapping among the two fields, the term Aerospace is often used to explain them both.

As with aeronautics, the restrictions of mass, temperatures, and outside forces require that application in space survive extreme situation: high-grade vacuum, the radiation attack of interplanetary space, the attractive belts of low Earth orbit. Space launch vehicles must endure titanic forces, while satellites can experience huge variations in hotness in very brief periods. Extreme constraints on mass cause astronautical engineers to face the steady need to save mass in the design in order to exploit the actual payload that reach orbit.

Wednesday, September 24, 2008

Airsickness

Airsickness is a sensation which is induces by air travel. It is a specific form of motion illness, and is considered a normal reply in healthy individuals. Airsickness occurs when the middle nervous system receives conflicting mail from the body moving balance and balance.

The inner ear is particularly significant in the preservation of balance and equilibrium since it contains sensors for both angular and linear movement. Airsickness is usually a mixture of spatial confusion, nausea and vomiting. Experimentally, airsickness can be eliminating in monkeys by remove part of the cerebellum, explicitly the nodulus of the vermis.

Wednesday, September 17, 2008

Aerostat

The word aerostat was initially French and is derived from the greek aer + statos . An aerostat is a lighter than air object that can stay motionless in the air. Aerostats comprise free balloons, airships, moor balloons and tethered Helikites. Such a vehicle is consists of a frivolous skin filled with a lifting gas to create resilience.

Technically, aerostats are capable of as long as "aerostatic" lift in that the force upwards arises without group through the nearby air mass. This contrasts with aerodynamic lift which requires the group of at least some part of the aircraft through the nearby air mass. However, in reality most aerostats obtain lift from together aerodynamic lift and pure gas lift at some time or other.

Aerostats are normally tethered lighter-than-air objects. Types of tethered aerostat include round balloons, blimps and Helikites.

Wednesday, September 10, 2008

Aerospace engineering

Aerospace engineering is the branch of engineering behind the plan, construction and discipline of aircraft and spacecraft. Aerospace engineering has broken down into two major and overlapping branches: aeronautical engineering and astronautical engineering. The earlier deals with craft that wait within Earth's atmosphere and the latter deals with craft those work outside of Earth's atmosphere. While "aeronautical" was the original term, the broader "aerospace" has outdated it in usage, as flight technology higher to include craft in service in outer space. Aerospace engineering is often casually called rocket science.

Tuesday, August 26, 2008

Aircraft

An aircraft is a medium which is able to fly throughout the Earth's atmosphere or through any other atmosphere. Most rocket vehicle is not aircraft because they are not support by the surrounding air. All the human action which environs aircraft is called aviation.

Manned aircraft are flying by a pilot. Until the 1960s, unmanned aircraft is called drones. During the 1960s, the U.S. military bring the term distantly piloted vehicle (RPV) into use. More lately the term unmanned aerial vehicle (UAV) has turn into common.

Tuesday, August 19, 2008

Aviation

Aviation refers to actions involving man-made flying devices, counting the people, organizations, and dictatorial bodies concerned with them.

Many cultures have built devices that travel during the air, from the earliest projectiles such as stones and spears, to more complicated buoyant or aerodynamic strategy such as the mechanical pigeon of Archytas in Ancient Greece, the boomerang in Australia, the hot air Kongming lantern, and kites. There are early myths of human flight such as the story of Icarus, and later, more believable claims of short-distance human flights counting a kite flight by Yuan Huangtou in China, and the parachute flight and forbidden glider flight of Abbas Ibn Firnas.

The practicality of balloons was incomplete because they could only travel downwind. It was instantly recognized that a steerable, or dirigible, balloon was necessary. Jean-Pierre Blanchard flew the first human-powered dirigible in 1784 and cross the English Channel in one in 1785. Subsequent early dirigible development included machine-powered propulsion, rigid frames, and better speed and maneuverability.

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

Tuesday, August 12, 2008

Aeronautics

Aeronautics is the science concerned with the study, design, and produce of flight-capable equipment, or the technique of in use aircraft. While the term accurately meaning "sailing the air" initially referred solely to the science of working the aircraft, it has since been extended to include technology, business and other aspect related to aircraft. One of the important parts in aeronautics is a branch of physical discipline called aerodynamics, which deal with the activity of air and the way that it interact with objects in movement, such as an aircraft. Aviation is a word sometimes used interchangeably with aeronautics, though "aeronautics" consists of lighter-than-air craft such as airships, while "aviation" does not.

Wednesday, August 06, 2008

Shuttlecock

A shuttlecock is a high-drag projectile used in the game of badminton. It has an open conical shape: the cone is shaped from sixteen overlapping goose feathers surrounded into a rounded cork base. The cork is covered with thin leather.

The shuttlecock's form makes it tremendously aerodynamically steady. Regardless of initial orientation, it will turn to fly cork first, and remain in the cork-first orientation.

The name shuttlecock is commonly shortened to shuttle; a shuttlecock may also be known as a bird or birdie. The abbreviation cock is rarely used except in a funny sense, due to its vulgar connotations. The "shuttle" part of the name was most likely derived from its back-and-forth movement during the game, similar to the shuttle of a loom; the "cock" part of the name was almost certainly derived from the likeness of the feathers to a bird's crest.

Tuesday, July 29, 2008

Flowers

A flower also recognized as a bloom or blossom, is the reproductive configuration establish in flowering plants. The flower's structure contains the plant's reproductive organs, and its role is to make seeds. After fertilization, portions of the flower build up into a fruit containing the seeds. For the high plants, seeds are the next production, and serve up as the primary means by which individuals of a variety are dispersed across the scenery. The grouping of flowers on a place is called the inflorescence.

Many flowers in natural world have evolved to magnetize animals to pollinate the flower, the actions of the pollinating means contributing to the chance for genetic recombination within a dispersed plant population. Flowers commonly have glands called nectarines on their various parts that attract these birds.

Tuesday, May 27, 2008

Amazon

At one time Amazon River flowed westward, perhaps as part of a proto-Congo (Zaire) river system from the interior of present day Africa when the continents were joined as part of Gondwana. Fifteen million years ago, the Andes were formed by the collision of the South American plate with the Nazca plate. The rise of the Andes and the linkage of the Brazilian and Guyana bedrock shields, blocked the river and caused the Amazon to become a vast inland sea. Gradually this inland sea became a massive swampy, freshwater lake and the marine inhabitants adapted to life in freshwater. For example, over 20 species of stingray, most closely related to those found in the Pacific Ocean, can be found today in the freshwaters of the Amazon. About ten million years ago, waters worked through the sandstone to the west and the Amazon began to flow eastward. At this time the Amazon rainforest was born.

During the Ice Age, sea levels dropped and the great Amazon lake rapidly drained and became a river. Three million years later, the ocean level receded enough to expose the Central American isthmus and allow mass migration of mammal species between the Americas. The Ice Ages caused tropical rainforest around the world to retreat. Although debated, it is believed that much of the Amazon reverted to savanna and montane forest (see chapter 3-Ice Ages and Glaciation). Savanna divided patches of rainforest into "islands" and separated existing species for periods long enough to allow genetic differentiation (a similar rainforest retreat took place in Africa. Delta core samples suggest that even the mighty Congo watershed was void of rainforest at this time). When the ice ages ended, the forest was again joined and the species that were once one had diverged significantly enough to be constitute designation as separate species, adding to the tremendous diversity of the region. About 6000 years ago, sea levels rose about 130 meters, once again causing the river to be inundated like a long, giant freshwater lake.