Aeronautics is the science involved with the study, design, and manufacture of flight-capable machines, or the techniques of operating aircraft. 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 it interacts with objects in motion, such as an aircraft. Aviation is a term sometimes used interchangeably with aeronautics, although "aeronautics" includes lighter-than-air craft such as airships, while "aviation" does not.^[1]

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.

Modern aeronautics

Modern aeronautic research is primarily conducted by independent corporations such as EU and universities. There are also a number of government agencies that study aeronautics, including NASA in the United States and the ESA in Europe.

Impact of wind shear on passenger aircraft

Main article: Wind shear

In the United States, a string of fatal accidents near thunderstorms downed passenger airliners during final descent and initial ascent, including Eastern Air Lines Flight 66 in New York (1975), Pan Am Flight 759 in New Orleans (1982), and Delta Air Lines Flight 191 at Dallas-Fort Worth (1985). The common cause in these air disasters was low level windshear.

Strong outflow from thunderstorms causes rapid changes in the three-dimensional wind velocity just above ground level. Air Force One landed five minutes before one of the strongest downbursts ever recorded in the Washington, D.C. area at Andrews Air Force Base, with President Ronald Reagan onboard.^[2] Initially, this outflow causes a headwind that increases airspeed, which normally causes a pilot to reduce engine power if they are unaware of the wind shear. As the aircraft passes into the region of the downdraft, the localized headwind diminishes, reducing the aircraft's airspeed, and increasing its sink rate. Then, when the aircraft passes through the other side of the downdraft, the headwind becomes a tailwind, reducing airspeed further, leaving the aircraft in a low-power, low-speed, descent. This can lead to an accident if the aircraft is too low to effect a recovery before ground contact.^[3]

As the result of the accidents in the 1970s and 1980s, in 1988 the U.S. Federal Aviation Administration mandated that all commercial aircraft have on-board windshear detection systems by 1993. Three airlines, United Airlines, Continental Airlines, and Northwest Airlines received extensions until the end of 1995 so to install predictive wind shear sensors rather than reactive systems in their aircraft. The results of these efforts was immediate. Between 1964 and 1985, wind shear directly caused or contributed to 26 major civil transport aircraft accidents in the U.S. that led to 620 deaths and 200 injuries. Of these accidents, 15 occurred during take-off, three during flight, and eight during landing. Since 1995, the number of major civil aircraft accidents caused by wind shear has dropped to approximately one every ten years due to the mandated on-board detection, as well as the addition of Doppler radar units on the ground. (NEXRAD)

Aeronautical engineering

Main article: Aerospace engineering

Aeronautical engineering is an engineering area that covers research, design, manufacture and maintenance of products such as aircraft, missiles and space satellites. It involves scientific topics of Aerodynamics, Heat Transfer, Materials, Technology, Fluid Mechanics and Aircraft Structures.

References

See also

• Aviation
• Aircraft
• Air safety
• Airsickness and airsickness bags
• Aerospace engineering
• Aerostat
• Astronautics
• Spacecraft
• Mechanics of fluids
• Aerodynamics
• Hydrodynamics
• Hydrostatics
• Aeronautical abbreviations

External links

• Aerospace courses at MIT OpenCourseWare
• American Institute of Aeronautics and Astronautics
• American Helicopter Society
• Examples of Aeronautic Designs
• A community for the people working in the aeronautics