In the early days of the airplane industry, engineers constructed airplanes in
 
A new aircraft starts life as a design on paper or on a computer screen. A manufacturer may plan a new model, such as an airliner or helicopter. Alternatively it may update an existing model, perhaps by lengthening the fuselage or giving it more powerful and more efficient engines. The manufacturer then offers the new product to the world market, by showing it at air shows, for example. (Air shows bring new products and and potential buyers together and they are open to the public as well.)
Other aircraft are commissioned by customers. The U. S. Department of Defense asks manufacturers to submit plans for new aircraft or missiles, setting out such details as size, speed, cost, and mission tasks. Sometimes, two or more prototypes are tested in competition. In the late 1980s, the U. S. government invited Boeing and Lockheed Martin to submit designs for an important new military airplane, the Joint Strike Fighter. This was a complex, multipurpose airplane, intended to replace not just one existing airplane but several different models. Both companies put forward a design, and Lockheed Martin’s F-35A won the contract. This decision will affect thousands of aerospace industry workers, since the new plane will probably be in service for at least thirty years from its scheduled release date of 2011.
 A new plane is thoroughly tested-sometimes for years-before it is ready to go into production. Few aircraft fly perfectly the first time, and many modifications may be made before airplanes start to roll off the assembly lines.
Most airplanes are now built, like automobiles, on a production line. Aircraft are rarely built on one site, however. Instead, subcontractors build different parts of the airplane, such as the wings and tail. Manufacturers select the engines from a specialized engine maker, such as GE-Aviation. The parts of the plane, with all of its electronics and other fittings, are then brought together and assembled at a large manufac – О Apache helicopters are assembled at a Boeing plant turing plant. in Mesa, Arizona.
small sheds. They used their own skill and ideas, plus what they read about other inventors’ “flying machines.” Orville and Wilbur Wright, for example, were bicycle engineers. The brothers built their first planes in the early 1900s just to see if they could fy.
Glenn Curtiss, another aviation pioneer, set up America’s first airplane manufacturing company in 1907. In 1909 two competitors entered the business field: the Wright brothers and Glenn L. Martin.
At first, all planes were built one at a time. Series production began in 1909, when the Short Brothers factory in the
f © s
MILITARY CONTRACT
The first contract for a U. S. military plane was awarded to the Wright brothers in 1907. Unfortunately, the aircraft crashed on September 17, 1908. Orville Wright, the pilot, survived, but his passenger, Lieutenant Thomas E. Selfridge of the U. S. Army Signal Corps, was killed. This was the first fatal accident in a powered airplane. In spite of the accident, the Wrights’ biplane was accepted by the U. S. Army. The brothers were even paid a bonus, because their plane flew 2 miles per hour (3.2 kilometers per hour) faster than the 40 miles per hour (64.4 kilometers per hour) the U. S. Army had requested.
_____________________________________________ J
United Kingdom built six identical Wright biplanes.
Before World War I (1914-1918), airplanes were built almost entirely by hand. They were made chiefly of wood, fabric, and wire. Furniture makers had the skills to build airplanes, and in wartime, some furniture factories switched to aircraft manufacture. By adopting the assembly line methods of automobile manufacturers such as Ford, aircraft companies were able to build planes faster. Two important names in aerospace history, Boeing and Lockheed, started building aircraft in 1916. By the end of World War I, U. S. factories had built more than 14,000 military planes.
After the war, more manufacturers started to supply aircraft for the fastgrowing civil aviation industry. Airline businesses were just beginning, and they needed airplanes. The first U. S. international scheduled airline service was in 1919, operated by Aero Marine West Indies Airways between Key West, Florida, and Havana, Cuba. In the 1920s, companies entering the airplane manufacturing industry included Douglas (1920), Pratt & Whitney (1925), and Grumman (1929).
In the pioneer days of aviation, a pilot relied on eyesight and navigated with a map, following ground landmarks such as highways and railroads. Rules to regulate air navigation were first introduced in the 1920s. The first air traffic controller began work in 1929 in St. Louis, Missouri. English became the international language of air traffic control, and agreed-upon words were adopted to prevent misunderstandings. At this time, radio was used to communicate with planes, but there was no radar to track aircraft movement until the 1940s.
The International Civil Aviation Organization (ICAO) was set up in 1947. Today, this agency of the United Nations regulates air traffic control worldwide as well as the boundaries of national airspace. It allocates call signs to each airline flight, usually an abbreviated form of the airline name (such as GLA for Great Lakes Airlines) followed by the number of the flight—for example, GLA 674 for flight 674. The call signs appear on radar screens, on flight plans, and on information boards at airports. Other civilian aircraft are usually identified by their registration numbers, a combination of letters and numbers displayed on the tail and wings—N3761P, for example. (The “N” is the international designation for the United States.)
ilitary aircraft are the airplanes and helicopters used by the world’s military forces. They are used for combat and for other military operations, including carrying supplies and troops, reconnaissance, training, and search and rescue.
In the United States all branches of the military (not just the U. S. Air Force) use aircraft. The United States has the world’s most powerful air force, and the U. S. Navy, Army, Marine Corps, and Air National Guard also have their own aircraft. Other major air forces include those of Russia, China, the United Kingdom, and France. Canada does not have a separate air force but has the Canadian Forces Air Command (AIRCOM) within the unified Canadian Forces.
The nerve center of a larger airport is the control tower. Air traffic controllers use radar, computers, and radio to direct the movement of airplanes in and out of the airport and on runways. The design and layout of runways is regulated by the government and by the International Civil Aviation Organization, to which most nations belong.
Early airplanes were light enough to land on a grass airfield. Modern passenger and cargo planes are so heavy that they need hard runways, constructed of concrete or tarmacadam. Because most modern jet planes need a lot of space to take off and land, runways have become longer, and airports now take up a lot of ground.
A typical airport today has a single main runway, often over 13,000 feet (3,960 meters) long. The runway must be long and wide enough for the largest
WIND FACTORS
Aircraft usually land and take off into the wind. For this reason, older airports had three or four runways, arranged in the shape of a triangle or box, so aircraft could land and take off no matter which direction the wind was blowing. Modern airplanes are so powerful that they are less affected by wind, and a modern airport can often operate efficiently with just one main runway. It may need extra runways, however, to cope with the number of passengers and amount of air cargo.
_____________________________________________ /
planes flying into the airport to take off and land safely. A runway has a clear space at each end in case a pilot requires extra distance when taking off or landing. Numbers on or beside the runway identify it by compass direction. For example, on a north-south runway, the numbers are 18 (short for 180°) at the north end, and 36 (short for 360°) at the south end. White lights mark the edges of the runway, and green lights are placed where the runway starts. There is an additional set of red and white approach lights, which pilots see as they prepare to touch down.
pollo was the name given to a project launched by the United States to fly astronauts to the Moon, land them, and return them safely to Earth. The spacecraft built for the project were also named Apollo. The name comes from Greek and Roman mythology-Apollo was the god of light, of healing and medicine, and of poetry and music.
The Political Background
Project Apollo involved a series of spaceflights to increase knowledge of the Moon and of manned spaceflight. The program was carried out at great speed and high cost in the 1960s. Many people doubted it would succeed.
In 1961, President John F. Kennedy announced to the U. S. Congress that the United States should aim to land astronauts on the Moon before 1970. At that time, the United States was in competition with the communist federation of nations then called the USSR, or Soviet Union. The Soviet Union had launched the first Earth satellite (Sputnik 1) in 1957, and in 1959 it had sent three unmanned Luna spacecraft to the Moon. Luna 2 crashed onto the Moon’s surface, while Luna 3 flew around the Moon to photograph its far side, never before seen on Earth. The Soviet Union had clearly taken the lead in what the media called the space race.
U. S. space scientists knew the Soviets were capable of launching heavy
|
О One of the first human marks on the Moon was made by the boot of astronaut Buzz Aldrin on July 20, 1969.
|
manned spacecraft using powerful booster rockets developed for the Soviet Union’s military missile program. The Soviets put the world’s first astronaut, Yuri Gagarin, into Earth orbit in April 1961. They followed this historic spaceflight with a 25-hour flight by Gherman Titov in August 1961. Many experts predicted that the Soviets would land on the Moon within a year or two.
Project Apollo was America’s answer to that challenge. The program went ahead despite skepticism from some scientists that manned exploration of the Moon was too risky and not worth such a vast expenditure of time, money, and expertise.
Today’s avionics include sensors, radio communications equipment, computers, and control and navigation systems. They also include the displays in the cockpit.
The job of sensors is to collect information. Sensors on the outside of an aircraft collect information about its speed and height. Other sensors in the engines monitor temperature, pressure, and speed. Yet others measure tire pressure. Sensors inside the plane monitor the air pressure and temperature. Radar in an airplane’s nose searches the sky ahead for storms.
Radio equipment lets the crew talk to air traffic controllers on the ground. Radios are also able to receive signals from navigation beacons on the ground and sometimes from satellites in space. Devices called transponders send out radio signals that identify each plane to air traffic controllers. Military aircraft have even more avionics for their weapons and defense systems.
Computers and other electronic systems process all the information arriving from the sensors. A huge amount of information floods into an aircraft’s
cockpit. The plane’s avionics help cut it down to a level that pilots can manage. Displays show the information pilots need on screens and other instruments.
It is possible that an airliner will be struck by lightning one or more times in a year. A lightning bolt produces millions of volts, and avionics can be put out of action by just a few volts too many. When lightning strikes an airplane, however, it flows around the plane’s metal body. It does not get inside the plane, and so the avionics are safe. The crew and passengers are protected from lightning in the same way.
Some parts of a plane’s body are now being built from light materials, such as carbon fiber, instead of metal. The new materials are used because they are lighter and stronger than most metals, but they do not keep lightning out in the way that metal does. One way to protect the delicate avionics in these aircraft is to cover the plastic or carbon fiber parts of the body with a thin metal mesh. If lightning hits the airplane, the metal layer stops it from reaching the computers and electronics inside.
Control systems enable the crew to control the aircraft. Some control systems, such as the autopilot, are automatic: They work by themselves. Others are manual and are operated by the crew. Actuators, for example, are an aircraft’s mechanical muscles. They move parts of the plane, such as the rudder in the tail, the moving parts of the wings, and the landing gear.
Dates of birth: Benz: November 25, 1844; Daimler: March 17, 1834.
Places of birth: Benz: Karlsruhe, Baden, present-day Germany; Daimler: Schorndorf, Wurttemberg, present-day Germany.
Died: Benz: April 4, 1929; Daimler: March 6, 1900.
Major contributions: Pioneers in automobile engines and founders of a company that advanced airplane and airplane engine design; Benz: inventor of the gasoline-powered automobile; Daimler: co-inventor of the first powered balloon to fly successfully.
|
О The Benz three-wheeler of 1885, with its
internal combustion engine, is widely considered to be the first gasoline-powered automobile.
|
arl Benz and Gottlieb Daimler were engineers who designed pioneering automobiles and car engines. Their work produced advanced designs that paved the way for aircraft engines. The two men never met, but the company that formed by merging their two businesses later produced important German aircraft engines.
Trained as an engineer, Karl Benz took an interest in developing an engine for a horseless carriage, or automobile. Another German, Nikolaus Otto, invented an internal combustion engine using a four-stroke piston in 1876. Two years later Benz invented a two-stroke version that improved on Otto’s design. Benz also designed several other key features of an automobile, including the spark plug, carburetor, clutch pedal, and gearshift. In 1885 he invented a vehicle run by a gasoline-powered engine. Although it had only three wheels, it is considered by historians to be the first practical, purpose-built automobile.
By 1899, the company Benz had formed was making more than 600 cars-now with four wheels-each year. For several years, his company was a leading automaker. A racecar it built in 1909 set a land speed record of 142 miles per hour (228 kilometers per hour).
Gottlieb Daimler also studied engineering and then partnered with Wilhelm Maybach, another mechanical engineer, to develop better engines. In 1885 they placed an engine on a bicycle, creating the world’s first motorcycle. Two years later, Daimler and Maybach
   produced the first speedboat. The next year, they placed an engine on a balloon, which was flown over the town of Seelberg. In 1890 Daimler and Maybach formed a company, but they often fell into conflict with other managers. Maybach himself left the company in 1891, and Daimler at one point lost his job as technical director. In 1900, after several years of ill health, Daimler died.
Both companies suffered in the 1920s. Germany’s economy was shattered after the nation’s defeat in World War I, and few people had the money to buy automobiles. In 1926 the companies merged to form Daimler – Benz. The new company achieved some success. It named its car the Mercedes – Benz, combining Daimler’s most popular model with the Benz name. Three years after the merger, Karl Benz died.
The company’s gains were partly fueled by a new field-developing aircraft engines. In the late 1920s, Daimler-Benz developed a powerful twelve-cylinder aircraft engine. In 1934, the company produced a landmark aircraft engine, the DB600. With more power and greater endurance than other engines, it was quickly adopted by German airplane manufacturers.
  By the late 1930s, Germany’s leaders were ignoring a World War I peace treaty that had banned Germany from manufacturing military airplanes. Many of the aircraft built by the Germans
Bleriot’s next design, the XI, showed promise. In July 1909, he set out for northern France to try the English Channel crossing.
There, he found two other fliers hoping to win the prize. Count Charles de Lambert crashed his plane, built by the Wright brothers, in a test run and
 withdrew from the contest. The second flier, Hubert Latham, took off on July 19, 1909, but crashed into the Channel. After being rescued, he called for another plane to be brought so he could try again. Several days of bad weather prevented anyone from flying, however.
Early on the morning of July 25, the weather cleared and the wind eased. While Latham slept, Bleriot decided to make the attempt. At 4:35 a. m., with dawn breaking, he took off. Latham was awakened, but by the time he was ready, the wind had picked up, and he could not fly.
Flying without a compass, Bleriot could only guess that he was heading north. After about thirty minutes, Bleriot spotted southeastern Britain. He landed on a field in triumph. In thirty-seven minutes, Bleriot had conquered the English Channel.
OPEN TO ATTACK
Bleriot’s flight across the English Channel provoked anxiety in the United Kingdom. For centuries, the English Channel had been a barrier to invasion. After Bleriot’s flight, newspaper editorials warned that the country would no longer be safe.
In time of war, they said, planes could fly from the Continent to attack the island.
_____________________________________________ /
Later Life
Bleriot’s feat gained him great fame and success. Very quickly, orders for his monoplanes poured in, helping him build another fortune. He took part in forming a company that made one of the most popular fighter planes of World War I, the SPAD. After the war, Bleriot manufactured commercial planes.
Bleriot’s flying career did not last much past his English Channel crossing. Later in 1909, he suffered an injury in another crash that forced him to give up flying. He continued to promote aviation and improvements in aircraft design until his death in 1936.
N
SEE ALSO:
• Aileron and Rudder • Biplane
• Fighter Plane • World War I
_________________ J
| |
cockpit, produce more shock waves, but the nose and tail shock waves are the biggest.
