The History Of Air Traffic Control
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The History Of Air Traffic Control
من طرف Ahmed Mosaad_ATC14 السبت مايو 24, 2008 1:09 pm
The History Of Air Traffic Control Archie William League, widely acknowledged as the first U.S. air traffic controller, was born in 1907 at Poplar Bluff, Missouri. He passed away on October 1, 1986 at the age of 79 in Annandale, Virginia. League retired from the F.A.A. in 1973, as the Assistant Administrator for Appraisal, with his claim to the first air traffic controller largely unchallenged. His distinguished career really began in the city of St. Louis (somewhere around 1929,) where he later earned a degree in Aeronautical Engineering at Washington University. After becoming a licensed airplane and engine mechanic, flying and barnstorming around Illinois and Missouri with his own 'flying circus', Archie was hired by the city to direct the growing air traffic at St. Louis's Lambert Field. His "control tower" was a wheelbarrow on which he mounted a beach umbrella for the summer heat. In it he carried a beach chair, his lunch, water, a note pad and a pair of signal flags to direct the aircraft either to ‘GO’ or ‘HOLD’. In the winters, he wore a padded flying suit to keep warm out on the field. In 1937, he joined the Bureau of Air Commerce (the precursor to the Civil Aeronautics Authority, and the Federal Aviation Administration), where he began a 36 year career in government service. He rose rapidly through the ranks as an Air Traffic controller, served as a pilot in World War II (where he rose to the rank of Colonel) then progressed to his first top management position in 1956, as Assistant Regional Administrator of the Central Region. He next went to Washington headquarters as Chief of the Planning Division (Planning and Development Office) in 1958. After a short assignment as Director, Bureau of National Capital Airports, he moved to Fort Worth as the Director of Southwest Region. His next assignment (and the true culmination of a long career in Aviation) was in May 1965, relocating to Washington headquarters as Director of Air Traffic Services, where he became head of the staff responsible for the safe and efficient operation of the nation’s air traffic control system. Air Traffic Control: Keeping Track of Flights By the end of the first decade of powered flight, people began to realize that aircraft, like automobiles, would crash into each other unless some means was developed to control and direct them. At first, because aircraft could not fly very high, such control was accomplished using simple hand signals. Later, control was exercised through radio communication. By the end of World War II, the invention of radar permitted visually displayed tracking of several aircraft at once. When coupled with radio communication, radar made it possible for the pilot to be warned when he was in danger of colliding with another aircraft or when he was off course. In 1956, two aircraft crashed over the Grand Canyon while one was climbing and the other descending. The resulting public outcry spurred the development of the modern radar-based air traffic control system. Today, aircraft are continually tracked from take-off to landing Brief History Of Aviation First Flight On December 17, 1903, Orville and Wilbur Wright capped four years of research and design efforts with a 120-foot, 12-second flight at Kitty Hawk, North Carolina - the first powered flight in a heavier-than-air machine. Prior to that, people had flown only in balloons and gliders. The first person to fly as a passenger was Leon Delagrange, who rode with French pilot Henri Farman from a meadow outside of Paris in 1908. Charles Furnas became the first American airplane passenger when he flew with Orville Wright at Kitty Hawk later that year. The first scheduled air service began in Florida on Jan. 1, 1914. Glenn Curtiss had designed a plane that could take off and land on water and thus could be built larger than any plane to date because it did not need the heavy undercarriage required for landing on hard ground. Thomas Benoist, an autoparts maker, decided to build such a flying boat, or seaplane, built for a service across Tampa Bay called the St. Petersburg-Tampa Air Boat Line. His first passenger was ex-St. Petersburg Mayor A.C. Pheil, who made the 18-mile trip in 23 minutes, a considerable improvement over the two-hour trip by boat or 12-hour trip by rail between the two cities. The single-plane service accommodated one passenger at a time, and the company charged a one-way fare of $5. After operating two flights a day for four months and carrying a total of 1,205 passengers, the company folded with the end of the winter tourist season. World War I These and other early flights were headline events, but commercial aviation was very slow to catch on with the general public, most of which was afraid to ride in the new flying machines. Improvements in aircraft design also were slow. However, with the advent of World War I, the military value of aircraft was quickly recognized and production increased significantly to meet the soaring demand for planes from governments on both sides of the Atlantic. Most significant was the development of more powerful motors, enabling aircraft to reach speeds of up to 130 mph, more than twice the speed of pre-war aircraft. Increased power also made bigger aircraft possible. On the other hand, the war was bad for commercial aviation in several respects. It focused all design and production efforts on building military aircraft. In the public's mind, flying became almost totally associated with bombing runs, surveillance, and aerial dog fights. In addition, there was such a large surplus of planes at the end of the war that the demand for new production was almost non-existent for several years - and many aircraft builders went bankrupt. Some European countries such as Great Britain and France nurtured commercial aviation by starting air service over the English Channel. However, nothing similar occurred in the United States where there were no such natural obstacles isolating major cities and where railroads could transport people almost as fast as an airplane, and in considerably more comfort. The salvation of U.S. commercial aviation industry following World War I was a government program, but one that had nothing to do with the transportation of people. Airmail By 1917, the U.S. government felt it had seen enough progress in the development of planes to warrant something totally new - air mail. That year, Congress appropriated $100,000 for an experimental airmail service that was to be conducted jointly by the Army and the Post Office between Washington and New York, with an intermediate stop in Philadelphia. The first flight left Belmont Park, Long Island, for Philadelphia on May 14, 1918, and the next day continued on to Washington where it was met by President Woodrow Wilson. With a large number of war-surplus aircraft in hand, the Post Office almost immediately set its sights on a far more ambitious goal - transcontinental air service. It opened the first segment, between Chicago and Cleveland, on May 15, 1919, and completed the service on Sept. 8, 1920, when the most difficult part of the route, the Rocky Mountains, was spanned. Airplanes still could not fly at night when the service first began, so the mail was handed off to trains at the end of each day. Nonetheless, by using airplanes the Post Office was able to shave 22 hours off coast-to- coast mail deliveries. |
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Ahmed Mosaad_ATC14- Silver Captian
- عدد الرسائل : 94
العمر : 37
تاريخ التسجيل : 07/05/2008 -
The History Of Air Traffic Control - Part 2
من طرف Ahmed Mosaad_ATC14 السبت مايو 24, 2008 1:25 pm
Beacons
In 1921, the Army deployed rotating beacons in a line between Columbus and Dayton, Ohio, a distance of about 80 miles. The beacons, visible to pilots at 10-second intervals, made it possible to fly the route at night.
The Post Office took over the operation of the guidance system the following year, and by the end of 1923 constructed similar beacons between Chicago and Cheyenne, WY, a line later extended coast-to-coast at a cost of $550,000. Mail then could be delivered across the continent in as little as 29 hours eastbound and 34 hours westbound (prevailing winds from west to east accounted for the difference), which was two to three days less than it took by train.
The Contract Air Mail Act of 1925
By the mid 1920s, the Post Office mail fleet was flying 2.5 million miles and delivering 14 million letters annually. However, the government had no intention of continuing airmail service on its own. Traditionally, the Post Office had used private companies for the transportation of mail. So once the feasibility of airmail was firmly established, and airline facilities were in place, the government moved to transfer airmail service to the private sector by way of competitive bids. The legislative vehicle for the move was the 1925 Contract Air Mail Act, commonly referred to as the Kelly Act after its chief sponsor, Rep. Clyde Kelly of Pennsylvania. It was the first major legislative step toward the creation of a private U.S. airline industry. Winners of the initial five contracts were National Air Transport (owned by the Curtiss Aeroplane Co.), Varney Air Lines, Western Air Express, Colonial Air Transport, and Robertson Aircraft Corporation. National and Varney would later become important parts of United Airlines (originally a joint venture of the Boeing Airplane Company and Pratt & Whitney). Western would merge with Transcontinental Air Transport (TAT), another Curtiss subsidiary, to form Transcontinental and Western Air (TWA). Robertson would become part of the Universal Aviation Corportation, which in turn would merge with Colonial, Southern Air Transport and others to form American Airways, predecessor of American Airlines. Juan Trippe, one of the original partners in Colonial, would later pioneer international air travel with Pan Am - a carrier he founded in 1927 to transport mail between Key West, FL, and Havana, Cuba; and Pitcairn Aviation, yet another Curtiss subsidiary that got its start transporting mail, would become Eastern Air Transport, predecessor of Eastern Airlines.
The Morrow Board
The same year Congress passed the Contract Mail Act, President Calvin Coolidge appointed a board to recommend a national aviation policy (a much-sought-after goal of Herbert Hoover, who was Secretary of Commerce at the time). Dwight Morrow, a senior partner in J.P. Morgan's bank, and later the father-in-law of Charles Lindbergh, was named chairman. The board heard testimony from 99 people, and on Nov. 30, 1925 submitted its report to President Coolidge. It was wide-ranging, but its key recommendation was that the government should set standards for civil aviation and that the standards should be set outside of the military.
The 1926 Air Commerce Act
Congress adopted the recommendations of the Morrow Board almost to the letter in the Air Commerce Act of 1926. The legislation authorized the Secretary of Commerce to designate air routes, to develop air navigation systems, to license pilots and aircraft, and to investigate accidents. In effect, the act brought the government back into commercial aviation, this time as regulator of the private airlines spawned by the Kelly Act of the previous year.
Congress also adopted the board's recommendation for airmail contracts by amending the Kelly Act to change the method of compensation for airmail services. Instead of paying carriers a percentage of the postage paid, the government would pay them according to the weight of the mail. This simplified payments, and it proved highly advantageous to the carriers, which collected $48 million from the government for the carriage of mail between 1926 and 1931.
Ford's Tin Goose
Henry Ford, the automobile manufacturer, was among the first successful bidders for airmail contracts, winning the right in 1925 to carry mail from Chicago to Detroit and Cleveland aboard planes his company already was using to transport spare parts for his automobile assembly plants. More importantly, he jumped into aircraft manufacturing and in 1927 produced the Ford Trimotor, commonly referred to as the "Tin Goose." It was one of the first all-metal planes, made of a new material called duralumin that was almost as light as aluminum and twice as strong. It also was the first plane designed primarily to carry passengers rather than mail. The Ford Trimotor had 12 passenger seats, a cabin high enough for a passenger to walk down the aisle without stooping, and room for a "stewardess," or flight attendant, the first of which were nurses hired by United in 1930 to serve meals and assist airsick passengers. Its three engines made it possible to fly higher and faster (up to 130 miles per hour), and its sturdy appearance, combined with the Ford name, had a reassuring effect on the public's perception of flying. However, it was another event in 1927 that brought unprecedented public attention to aviation and helped secure the industry's future as a major mode of transportation.
Charles Lindbergh
Slightly before 8 a.m. on May 21, 1927, a young pilot named Charles Lindbergh set out on an historic flight across the Atlantic Ocean, from New York to Paris. It was the first continent-to-continent non-stop solo flight in an airplane, and its effect on both Lindbergh and aviation was enormous. Lindbergh became an instant American hero. Aviation became a more established industry, attracting millions of private investment dollars almost overnight as well as the imagination and support of millions of Americans.
The pilot that sparked all of this attention had dropped out of engineering school at the University of Wisconsin to learn how to fly. He became a barnstormer, doing aerial shows across the country, and eventually joined the Robertson Aircraft Corporation to transport mail between St. Louis and Chicago.
In planning his transatlantic voyage, Lindbergh daringly decided to fly by himself, without a navigator, so he could carry more fuel. His plane, the Spirit of St. Louis, was slightly under 28 feet in length, with a wingspan of 46 feet, and it carried 450 gallons of gasoline that comprised half its takeoff weight. There was too little room in the cramped cockpit for navigating by the stars, so Lindbergh flew by dead reckoning. He divided maps from his local library into 33 100-mile segments, noting the heading he would follow as he flew each segment. When he first sighted the coast of Ireland, he was almost exactly on the route he had plotted, and he landed several hours later with 80 gallons of fuel to spare.
Lindbergh's greatest enemy on his journey was fatigue. The trip took an exhausting 33 1/2 hours, but he managed to keep awake by sticking his head out the window to inhale cold air, by holding his eyelids open, and by constantly reminding himself that if he fell asleep he would perish. In addition, he had a slight instability built into his airplane that helped keep him focused and awake.
Lindbergh landed at Le Bourget outside of Paris at 10:24 p.m. Paris time on May 22. Word of his flight had preceded him and a large crowd of Parisians rushed out to the airfield to see him and his little plane. There was no question about the magnitude of what he had accomplished. The air age had arrived.
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أحمد مسعد
In 1921, the Army deployed rotating beacons in a line between Columbus and Dayton, Ohio, a distance of about 80 miles. The beacons, visible to pilots at 10-second intervals, made it possible to fly the route at night.
The Post Office took over the operation of the guidance system the following year, and by the end of 1923 constructed similar beacons between Chicago and Cheyenne, WY, a line later extended coast-to-coast at a cost of $550,000. Mail then could be delivered across the continent in as little as 29 hours eastbound and 34 hours westbound (prevailing winds from west to east accounted for the difference), which was two to three days less than it took by train.
The Contract Air Mail Act of 1925
By the mid 1920s, the Post Office mail fleet was flying 2.5 million miles and delivering 14 million letters annually. However, the government had no intention of continuing airmail service on its own. Traditionally, the Post Office had used private companies for the transportation of mail. So once the feasibility of airmail was firmly established, and airline facilities were in place, the government moved to transfer airmail service to the private sector by way of competitive bids. The legislative vehicle for the move was the 1925 Contract Air Mail Act, commonly referred to as the Kelly Act after its chief sponsor, Rep. Clyde Kelly of Pennsylvania. It was the first major legislative step toward the creation of a private U.S. airline industry. Winners of the initial five contracts were National Air Transport (owned by the Curtiss Aeroplane Co.), Varney Air Lines, Western Air Express, Colonial Air Transport, and Robertson Aircraft Corporation. National and Varney would later become important parts of United Airlines (originally a joint venture of the Boeing Airplane Company and Pratt & Whitney). Western would merge with Transcontinental Air Transport (TAT), another Curtiss subsidiary, to form Transcontinental and Western Air (TWA). Robertson would become part of the Universal Aviation Corportation, which in turn would merge with Colonial, Southern Air Transport and others to form American Airways, predecessor of American Airlines. Juan Trippe, one of the original partners in Colonial, would later pioneer international air travel with Pan Am - a carrier he founded in 1927 to transport mail between Key West, FL, and Havana, Cuba; and Pitcairn Aviation, yet another Curtiss subsidiary that got its start transporting mail, would become Eastern Air Transport, predecessor of Eastern Airlines.
The Morrow Board
The same year Congress passed the Contract Mail Act, President Calvin Coolidge appointed a board to recommend a national aviation policy (a much-sought-after goal of Herbert Hoover, who was Secretary of Commerce at the time). Dwight Morrow, a senior partner in J.P. Morgan's bank, and later the father-in-law of Charles Lindbergh, was named chairman. The board heard testimony from 99 people, and on Nov. 30, 1925 submitted its report to President Coolidge. It was wide-ranging, but its key recommendation was that the government should set standards for civil aviation and that the standards should be set outside of the military.
The 1926 Air Commerce Act
Congress adopted the recommendations of the Morrow Board almost to the letter in the Air Commerce Act of 1926. The legislation authorized the Secretary of Commerce to designate air routes, to develop air navigation systems, to license pilots and aircraft, and to investigate accidents. In effect, the act brought the government back into commercial aviation, this time as regulator of the private airlines spawned by the Kelly Act of the previous year.
Congress also adopted the board's recommendation for airmail contracts by amending the Kelly Act to change the method of compensation for airmail services. Instead of paying carriers a percentage of the postage paid, the government would pay them according to the weight of the mail. This simplified payments, and it proved highly advantageous to the carriers, which collected $48 million from the government for the carriage of mail between 1926 and 1931.
Ford's Tin Goose
Henry Ford, the automobile manufacturer, was among the first successful bidders for airmail contracts, winning the right in 1925 to carry mail from Chicago to Detroit and Cleveland aboard planes his company already was using to transport spare parts for his automobile assembly plants. More importantly, he jumped into aircraft manufacturing and in 1927 produced the Ford Trimotor, commonly referred to as the "Tin Goose." It was one of the first all-metal planes, made of a new material called duralumin that was almost as light as aluminum and twice as strong. It also was the first plane designed primarily to carry passengers rather than mail. The Ford Trimotor had 12 passenger seats, a cabin high enough for a passenger to walk down the aisle without stooping, and room for a "stewardess," or flight attendant, the first of which were nurses hired by United in 1930 to serve meals and assist airsick passengers. Its three engines made it possible to fly higher and faster (up to 130 miles per hour), and its sturdy appearance, combined with the Ford name, had a reassuring effect on the public's perception of flying. However, it was another event in 1927 that brought unprecedented public attention to aviation and helped secure the industry's future as a major mode of transportation.
Charles Lindbergh
Slightly before 8 a.m. on May 21, 1927, a young pilot named Charles Lindbergh set out on an historic flight across the Atlantic Ocean, from New York to Paris. It was the first continent-to-continent non-stop solo flight in an airplane, and its effect on both Lindbergh and aviation was enormous. Lindbergh became an instant American hero. Aviation became a more established industry, attracting millions of private investment dollars almost overnight as well as the imagination and support of millions of Americans.
The pilot that sparked all of this attention had dropped out of engineering school at the University of Wisconsin to learn how to fly. He became a barnstormer, doing aerial shows across the country, and eventually joined the Robertson Aircraft Corporation to transport mail between St. Louis and Chicago.
In planning his transatlantic voyage, Lindbergh daringly decided to fly by himself, without a navigator, so he could carry more fuel. His plane, the Spirit of St. Louis, was slightly under 28 feet in length, with a wingspan of 46 feet, and it carried 450 gallons of gasoline that comprised half its takeoff weight. There was too little room in the cramped cockpit for navigating by the stars, so Lindbergh flew by dead reckoning. He divided maps from his local library into 33 100-mile segments, noting the heading he would follow as he flew each segment. When he first sighted the coast of Ireland, he was almost exactly on the route he had plotted, and he landed several hours later with 80 gallons of fuel to spare.
Lindbergh's greatest enemy on his journey was fatigue. The trip took an exhausting 33 1/2 hours, but he managed to keep awake by sticking his head out the window to inhale cold air, by holding his eyelids open, and by constantly reminding himself that if he fell asleep he would perish. In addition, he had a slight instability built into his airplane that helped keep him focused and awake.
Lindbergh landed at Le Bourget outside of Paris at 10:24 p.m. Paris time on May 22. Word of his flight had preceded him and a large crowd of Parisians rushed out to the airfield to see him and his little plane. There was no question about the magnitude of what he had accomplished. The air age had arrived.
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أحمد مسعد
Ahmed Mosaad_ATC14- Silver Captian
- عدد الرسائل : 94
العمر : 37
تاريخ التسجيل : 07/05/2008 -
The History Of Air Traffic Control - Part 3
من طرف Ahmed Mosaad_ATC14 السبت مايو 24, 2008 1:30 pm
The Watres Act and the Spoils Conference
In 1930, Postmaster General Walter Brown pushed for legislation that would have another major impact on the development of commercial aviation. Known as the Watres Act (after one of its chief sponsors, Rep. Laurence H. Watres of Pennsylvania), it authorized the Post Office to enter into longer term contracts for airmail, with rates based on space, or volume, rather than weight. In addition, the act authorized the Post Office to consolidate airmail routes where it was in the national interest to do so. Brown believed the changes would promote larger, stronger airlines as well as more coast-to-coast and nighttime service.
Immediately after Congress approved the act, Brown held a series of meetings in Washington to discuss the new contracts. The meetings were later dubbed the "spoils conference" because Brown gave them little publicity and directly invited only a handful of people from the larger airlines. He designated three transcontinental mail routes and made it clear that he wanted only one company operating each service rather than a number of small airlines handing the mail off to one another across the United States. Brown got what he wanted - three large airlines (American, TWA and United) to transport the mail coast-to-coast - but his actions also brought political trouble that resulted in major changes to the system two years later.
Scandal and the Air Mail Act of 1934
Following the Democratic landslide of 1932, some of the smaller airlines began telling news reporters and politicians alike that they had been unfairly denied airmail contracts by Brown. One reporter discovered that a major contract had been awarded to an airline whose bid was three times higher than a rival bid from a smaller airline. Congressional hearings followed, chaired by Sen. Hugo Black of Alabama, and by 1934 the scandal had reached such proportions as to prompt President Franklin Roosevelt to cancel all mail contracts and turn mail deliveries over to the Army.
The decision was a mistake. The Army pilots were unfamiliar with the mail routes, and the weather at the time they took over the deliveries (February, 1934) was terrible. There were a number of accidents as the pilots flew practice runs and began carrying the mail, leading to newspaper headlines that forced President Roosevelt to retreat from his plan only a month after he had turned the mail over to the Army.
By means of the Air Mail Act of 1934, the government once again tendered the mail to the private sector, but it did so under a new set of rules that would have a significant impact on the industry. Bidding was structured to be more competitive, and former contract holders were not allowed to bid at all, so companies changed their names and appointed new executives. The result was a more even distribution of the government's mail business, and lower mail rates that forced airlines, and aircraft manufacturers, to pay more attention to the development of the passenger side of the business.
In another major change, the government forced the dismantling of the vertical holding companies common up to that time in the industry, sending aircraft manufacturers and airline operators (most notably Boeing, Pratt & Whitney, and United Airlines) their separate ways. The industry was reorganized and refocused.
Aircraft Innovations
For the airlines to attract more passengers away from the railroads, they needed both larger and faster airplanes. They also needed safer airplanes. Accidents such as the one in 1931 that killed Notre Dame football coach Knute Rockne and six other men kept people away from flying in droves.
Aircraft manufacturers responded to the challenge. There were so many improvements to aircraft in the 1930s that many believe it was the most innovative period in aviation history. Air-cooled engines replaced water-cooled engines, reducing weight and making bigger and faster planes possible. Cockpit instruments also improved, with better turn indicators, altimeters, airspeed indicators, rate of climb indicators, compasses, and the "artificial horizon," which showed pilots the attitude of the aircraft relative to the ground - important for flying in reduced visibility.
Radio
Another development of enormous importance to aviation was radio. Aviation and radio developed almost in lock step. Marconi sent his first message across the Atlantic on the airways just two years before the Wright Brothers' first flight at Kitty Hawk. By World War I, some pilots were taking radios up in the air with them so they could communicate with people on the ground. The airlines followed suit after the war, using radio to transmit weather information from the ground to their pilots so they could avoid storms.
Perhaps an even bigger development, however, was the realization that radio could be used as an aid to navigation when visibility was poor and visual navigation aids such as beacons were useless. Once technical bugs were worked out, the Department of Commerce constructed 83 radio beacons across the country. They became fully operational in 1932, automatically transmitting directional beams, or tracks, that pilots could follow to their destination. Marker beacons came next, allowing pilots to locate airports in poor visibility. The first air traffic control tower was established in 1935 at Newark International Airport in New Jersey.
Modern Airliners
Boeing built what generally is considered the first modern passenger airliner, the Boeing 247. It was unveiled in 1933, and United Air Lines promptly bought sixty of them, tying up Boeing production lines for two years. Based on a low-wing, twin-engine bomber with retractable landing gear, the 247 accommodated 10 passengers and cruised at 155 miles per hour. Its cabin was insulated to reduce engine noise levels inside the plane, and it featured such things as upholstered seats and a hot water heater to make flying more comfortable to passengers. Eventually, Boeing also gave the 247 variable pitch propellers that reduced takeoff distances, increased the rate of climb, and boosted cruising speeds.
Not to be outdone by United, TWA went searching for an alternative to the 247 and eventually found what it wanted from the Douglas Aircraft Company. Its DC-1 copied Boeing's innovations and improved upon many of them. The DC-1 had a more powerful engine and accommodations for two more passengers than did the 247. More importantly, the airframe was designed so that the skin of the aircraft bore most of the stress on the plane during flight. There was no interior skeleton of metal spars, thus giving passengers more room than they had in the 247.
The DC-1 also was easier to fly. It was equipped with the first automatic pilot and the first efficient wing flaps for added lift during takeoff. However, for all its advancements, only one DC-1 was ever built. Douglas decided almost immediately to alter its design, adding 18 inches to its length so it could accommodate two more passengers. The new, longer version was called the DC-2, and it was a big success, but the best was still to come.
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أحمد مسعد
In 1930, Postmaster General Walter Brown pushed for legislation that would have another major impact on the development of commercial aviation. Known as the Watres Act (after one of its chief sponsors, Rep. Laurence H. Watres of Pennsylvania), it authorized the Post Office to enter into longer term contracts for airmail, with rates based on space, or volume, rather than weight. In addition, the act authorized the Post Office to consolidate airmail routes where it was in the national interest to do so. Brown believed the changes would promote larger, stronger airlines as well as more coast-to-coast and nighttime service.
Immediately after Congress approved the act, Brown held a series of meetings in Washington to discuss the new contracts. The meetings were later dubbed the "spoils conference" because Brown gave them little publicity and directly invited only a handful of people from the larger airlines. He designated three transcontinental mail routes and made it clear that he wanted only one company operating each service rather than a number of small airlines handing the mail off to one another across the United States. Brown got what he wanted - three large airlines (American, TWA and United) to transport the mail coast-to-coast - but his actions also brought political trouble that resulted in major changes to the system two years later.
Scandal and the Air Mail Act of 1934
Following the Democratic landslide of 1932, some of the smaller airlines began telling news reporters and politicians alike that they had been unfairly denied airmail contracts by Brown. One reporter discovered that a major contract had been awarded to an airline whose bid was three times higher than a rival bid from a smaller airline. Congressional hearings followed, chaired by Sen. Hugo Black of Alabama, and by 1934 the scandal had reached such proportions as to prompt President Franklin Roosevelt to cancel all mail contracts and turn mail deliveries over to the Army.
The decision was a mistake. The Army pilots were unfamiliar with the mail routes, and the weather at the time they took over the deliveries (February, 1934) was terrible. There were a number of accidents as the pilots flew practice runs and began carrying the mail, leading to newspaper headlines that forced President Roosevelt to retreat from his plan only a month after he had turned the mail over to the Army.
By means of the Air Mail Act of 1934, the government once again tendered the mail to the private sector, but it did so under a new set of rules that would have a significant impact on the industry. Bidding was structured to be more competitive, and former contract holders were not allowed to bid at all, so companies changed their names and appointed new executives. The result was a more even distribution of the government's mail business, and lower mail rates that forced airlines, and aircraft manufacturers, to pay more attention to the development of the passenger side of the business.
In another major change, the government forced the dismantling of the vertical holding companies common up to that time in the industry, sending aircraft manufacturers and airline operators (most notably Boeing, Pratt & Whitney, and United Airlines) their separate ways. The industry was reorganized and refocused.
Aircraft Innovations
For the airlines to attract more passengers away from the railroads, they needed both larger and faster airplanes. They also needed safer airplanes. Accidents such as the one in 1931 that killed Notre Dame football coach Knute Rockne and six other men kept people away from flying in droves.
Aircraft manufacturers responded to the challenge. There were so many improvements to aircraft in the 1930s that many believe it was the most innovative period in aviation history. Air-cooled engines replaced water-cooled engines, reducing weight and making bigger and faster planes possible. Cockpit instruments also improved, with better turn indicators, altimeters, airspeed indicators, rate of climb indicators, compasses, and the "artificial horizon," which showed pilots the attitude of the aircraft relative to the ground - important for flying in reduced visibility.
Radio
Another development of enormous importance to aviation was radio. Aviation and radio developed almost in lock step. Marconi sent his first message across the Atlantic on the airways just two years before the Wright Brothers' first flight at Kitty Hawk. By World War I, some pilots were taking radios up in the air with them so they could communicate with people on the ground. The airlines followed suit after the war, using radio to transmit weather information from the ground to their pilots so they could avoid storms.
Perhaps an even bigger development, however, was the realization that radio could be used as an aid to navigation when visibility was poor and visual navigation aids such as beacons were useless. Once technical bugs were worked out, the Department of Commerce constructed 83 radio beacons across the country. They became fully operational in 1932, automatically transmitting directional beams, or tracks, that pilots could follow to their destination. Marker beacons came next, allowing pilots to locate airports in poor visibility. The first air traffic control tower was established in 1935 at Newark International Airport in New Jersey.
Modern Airliners
Boeing built what generally is considered the first modern passenger airliner, the Boeing 247. It was unveiled in 1933, and United Air Lines promptly bought sixty of them, tying up Boeing production lines for two years. Based on a low-wing, twin-engine bomber with retractable landing gear, the 247 accommodated 10 passengers and cruised at 155 miles per hour. Its cabin was insulated to reduce engine noise levels inside the plane, and it featured such things as upholstered seats and a hot water heater to make flying more comfortable to passengers. Eventually, Boeing also gave the 247 variable pitch propellers that reduced takeoff distances, increased the rate of climb, and boosted cruising speeds.
Not to be outdone by United, TWA went searching for an alternative to the 247 and eventually found what it wanted from the Douglas Aircraft Company. Its DC-1 copied Boeing's innovations and improved upon many of them. The DC-1 had a more powerful engine and accommodations for two more passengers than did the 247. More importantly, the airframe was designed so that the skin of the aircraft bore most of the stress on the plane during flight. There was no interior skeleton of metal spars, thus giving passengers more room than they had in the 247.
The DC-1 also was easier to fly. It was equipped with the first automatic pilot and the first efficient wing flaps for added lift during takeoff. However, for all its advancements, only one DC-1 was ever built. Douglas decided almost immediately to alter its design, adding 18 inches to its length so it could accommodate two more passengers. The new, longer version was called the DC-2, and it was a big success, but the best was still to come.
منقول من احد المواقع
أحمد مسعد
Ahmed Mosaad_ATC14- Silver Captian
- عدد الرسائل : 94
العمر : 37
تاريخ التسجيل : 07/05/2008 -
The History Of Air Traffic Control - Part 4
من طرف Ahmed Mosaad_ATC14 السبت مايو 24, 2008 1:35 pm
The DC-3
Called the plane that changed the world, the DC-3 was the first aircraft to enable airlines to make money carrying passengers. As a result, it quickly became the dominant aircraft in the United States following its debut in 1936 with American Airlines (which played a key role in its design).
The DC-3 had 50% greater passenger capacity than the DC-2 (21 seats versus 14), yet cost only 10% more to operate. It also was considered a safer plane, built of an aluminum alloy 25% stronger than materials previously used in aircraft construction. It has more powerful engines (1,000 horsepower versus 710 horsepower for the DC-2), and it could travel coast to coast in 16 hours - a fast trip for that time.
Another important improvement was the use of a hydraulic pump to lower and raise the landing gear. This freed pilots from having to crank the gear up and down during takeoffs and landings. For greater passenger comfort, the DC-3 had a noise-deadening plastic insulation, and seats set in rubber to minimize vibrations. It was a fantastically popular airplane, and it helped attract many new travelers to flying.
Pressurized Cabins
Although planes such as the Boeing 247 and the DC-3 represented significant advances in aircraft design, they had a major drawback. They could fly no higher than 10,000 feet because people became dizzy and even fainted due to the reduced levels of oxygen at higher altitudes.
The airlines wanted to fly higher to get above the air turbulence and storms common at lower altitudes. Motion sickness was a problem for many airline passengers, and an inhibiting factor to the industry's growth.
The breakthrough came at Boeing with the Stratoliner, a derivation of the B-17 bomber introduced in 1940 and first flown by TWA. It was the first pressurized aircraft, meaning that air was pumped into the aircraft as it gained altitude to maintain an atmosphere inside the cabin similar to the atmosphere that occurs naturally at lower altitudes. With its regulated air compressor, the 33-seat Stratoliner could fly as high as 20,000 feet and reach speeds of 200 miles per hour.
The 1938 Civil Aeronautics Act
Government decisions continued to prove as important to aviation's future as technological breakthroughs, and one of the most important aviation bills ever enacted by Congress was the 1938 Civil Aeronautics Act. Until that time, numerous government agencies and departments had a hand in aviation policy. Airlines sometimes were pushed and pulled in several directions, and there was no central agency working for the long term interests and stability of the industry. All the airlines had been losing money since the postal reforms in 1934 significantly reduced the amount they were paid for carrying the mail, and all were at risk of losing postal routes (still key to staying in business) to a low competing bid at the next Post Office auction.
The airlines desperately wanted greater government regulation through an independent agency they could call their own, and the Civil Aeronautics Act gave them what they wanted. It created the Civil Aeronautics Authority (CAA), and gave the new agency power to regulate airline tariffs, airmail rates, interline agreements, mergers, and airline routes. Its mission was to preserve order in the industry, holding rates to reasonable levels while at the same time nurturing the still financially-shaky airline industry by protecting carriers from unbridled competition.
Congress created a separate agency - the Air Safety Board - to regulate the carriers on matters of safety. In 1940, however, President Roosevelt convinced Congress to transfer the safety regulatory function to the CAA, which was then renamed the Civil Aeronautics Board (CAB). These moves, coupled with the tremendous progress made on the technological side, put the industry firmly on the road to success.
World War II
Aviation had an enormous impact on the course of World War II and the war had just as big of an impact on aviation. There were fewer than 300 air transports in the United States when Hitler marched into Poland in 1939. By the end of the war, U.S. aircraft manufacturers were producing 50,000 planes a year!
Most of the planes, of course, were fighters and bombers, but the importance of air transports to the war effort quickly became apparent as well. Throughout the war, the airlines provided much needed airlift to keep people and supplies moving to the front and throughout the production chain back home. For the first time in their history, the airlines had far more business - for passengers as well as freight - than they could handle. Many of them also had opportunities to pioneer new routes, gaining an exposure that would give them a decidedly broader outlook at war's end.
While there were numerous advances in U.S. aircraft design during the war that enabled planes to go faster, higher, and further than ever before, mass production was the chief goal of the United States. The major innovations of the wartime period - radar and jet engines - occurred in Europe.
The Jet Engine
Isaac Newton was the first to theorize (in the 18th century) that a rearward-channeled explosion could propel a machine forward at a great rate of speed. However, no one found a practical application for the theory until Frank Whittle, a British pilot, designed the first jet engine in 1930. Even then, widespread skepticism about the commercial viability of a jet prevented Whittle's design from being tested for several years.
The Germans were the first to actually build and test a jet aircraft. Based on a design by Hans von Ohain, a student working independent of Whittle, it flew in 1939, although not as well as the Germans had hoped. It would take another five years for German scientists to perfect the design, by which time it was too late to affect the outcome of the war.
Whittle also improved his jet engine during the war, and in 1942 he shipped an engine prototype to General Electric in the United States. America's first jet plane was built the following year.
Radar
A technological development with a much greater impact on the war's outcome (and later on commercial aviation) was radar. British scientists had been working on a device that could give them early warning of approaching enemy aircraft even before the war began, and by 1940 Britain had a line of radar transceivers along its east coast that could detect German aircraft the moment they took off from the Continent.
British scientists also perfected the cathode ray oscilloscope, which produced map-type outlines of surrounding countryside and showed aircraft as a pulsing light. Americans, meanwhile, found a way to distinguish between enemy aircraft and Allied aircraft by installing transponders aboard the later that signaled their identity to radar operators.
Dawn of the Jet Age
Aviation was poised to advance rapidly following the war, in large part because of the development of jets, but there still were significant problems to overcome. In 1952 a 36-seat British-made jet called the Comet flew from London to Johannesburg, South Africa, at speeds as high as 500 miles per hour. Two years later, the Comet's career ended abruptly following two back-to-back accidents in which the fuselage burst apart during flight - the result of metal fatigue caused by repeated pressurization cycles.
The cold war between the Soviet Union and the United States following World War II helped secure the funding needed to solve such problems and advance the jet's development. Most of the breakthroughs related to military aircraft that later were applied to the commercial sector. For example, Boeing employed a swept-back wing design for its B-47 and B-52 bombers to reduce drag and increase speed. Later, the design was incorporated into commercial jets, making them faster and thus more attractive to passengers. The best example of military-civilian technology transfer was the jet tanker Boeing designed for the Air Force to refuel bombers in flight, thus extending their range. The tanker, called the KC- 135, was a huge success as a military plane but even more successful when revamped and introduced in 1958 as the first U.S. passenger jet, the Boeing 707. With a length of 125 feet and four engines with 17,000 pounds of thrust, the 707 could carry up to 181 passengers and travel at speeds as high as 550 miles per hour. Its engines proved more reliable than piston driven engines, and they produced less vibration, putting less stress on the plane's airframe and reducing maintenance expenses. They also burned kerosene, which cost half as much as the high octane gasoline used in more traditional planes. With the 707, first ordered and operated by Pan Am, all questions about the commercial feasibility of jets were answered. The jet age had arrived, and other airlines soon were lining up to buy the new aircraft.
The Federal Aviation Act of 1958
Following World War II, air travel soared, but with the industry's growth came new problems. In 1956 two aircraft collided over the Grand Canyon and 128 people were killed. The skies were getting too crowded for existing systems of aircraft separation, and Congress responded by passing the Federal Aviation Act in 1958.
The legislation created a new safety regulatory agency, the Federal Aviation Agency, later called the Federal Aviation Administration when Congress created the Department of Transportation in 1967. The agency was charged with establishing and running a broad air traffic control system to maintain safe separation of all commercial aircraft through all phases of flight. In addition, it assumed jurisdiction over all other aviation safety matters, such as the certification of aircraft designs, and airline training and maintenance programs. The Civil Aeronautics Board retained jurisdiction solely over economic matters, such as airline routes and rates.
Widebodies and Supersonics
1969 marked the debut of another revolutionary aircraft, the Boeing 747, which Pan Am was the first to purchase and fly in commercial service. It was the first widebody jet, with two aisles, a distinctive upper deck over the front section of the fuselage, and four engines under its wings. With seating for as many as 450 passengers, it was twice as big as any other Boeing jet and 80% bigger than the largest jet up until that time, the DC-8.
Recognizing the economies of scale to be gained from larger jets, other aircraft manufacturers quickly followed suit. Douglas built its first widebody, the DC-10, in 1970, and only a month later, Lockheed flew its contender in the widebody market, the L-1011. Both of these jets had three engines (one under each wing and one on the tail) and were smaller than the 747, seating about 250 passengers.
During the same period of time, efforts were underway in both the United States and Europe to build a supersonic commercial aircraft. The Soviet Union was the first to succeed, testing the Tupolev 144 in December of 1968. A consortium of West European aircraft manufacturers first flew the Concorde two months later and eventually produced a number of those fast, but small, jets for commercial service. U.S. efforts to produce a supersonic passenger jet, on the other hand, foundered in 1971 due to public concern about the sonic boom produced by such aircraft. U.S. airlines have never operated a supersonic aircraft.
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أحمد مسعد
Called the plane that changed the world, the DC-3 was the first aircraft to enable airlines to make money carrying passengers. As a result, it quickly became the dominant aircraft in the United States following its debut in 1936 with American Airlines (which played a key role in its design).
The DC-3 had 50% greater passenger capacity than the DC-2 (21 seats versus 14), yet cost only 10% more to operate. It also was considered a safer plane, built of an aluminum alloy 25% stronger than materials previously used in aircraft construction. It has more powerful engines (1,000 horsepower versus 710 horsepower for the DC-2), and it could travel coast to coast in 16 hours - a fast trip for that time.
Another important improvement was the use of a hydraulic pump to lower and raise the landing gear. This freed pilots from having to crank the gear up and down during takeoffs and landings. For greater passenger comfort, the DC-3 had a noise-deadening plastic insulation, and seats set in rubber to minimize vibrations. It was a fantastically popular airplane, and it helped attract many new travelers to flying.
Pressurized Cabins
Although planes such as the Boeing 247 and the DC-3 represented significant advances in aircraft design, they had a major drawback. They could fly no higher than 10,000 feet because people became dizzy and even fainted due to the reduced levels of oxygen at higher altitudes.
The airlines wanted to fly higher to get above the air turbulence and storms common at lower altitudes. Motion sickness was a problem for many airline passengers, and an inhibiting factor to the industry's growth.
The breakthrough came at Boeing with the Stratoliner, a derivation of the B-17 bomber introduced in 1940 and first flown by TWA. It was the first pressurized aircraft, meaning that air was pumped into the aircraft as it gained altitude to maintain an atmosphere inside the cabin similar to the atmosphere that occurs naturally at lower altitudes. With its regulated air compressor, the 33-seat Stratoliner could fly as high as 20,000 feet and reach speeds of 200 miles per hour.
The 1938 Civil Aeronautics Act
Government decisions continued to prove as important to aviation's future as technological breakthroughs, and one of the most important aviation bills ever enacted by Congress was the 1938 Civil Aeronautics Act. Until that time, numerous government agencies and departments had a hand in aviation policy. Airlines sometimes were pushed and pulled in several directions, and there was no central agency working for the long term interests and stability of the industry. All the airlines had been losing money since the postal reforms in 1934 significantly reduced the amount they were paid for carrying the mail, and all were at risk of losing postal routes (still key to staying in business) to a low competing bid at the next Post Office auction.
The airlines desperately wanted greater government regulation through an independent agency they could call their own, and the Civil Aeronautics Act gave them what they wanted. It created the Civil Aeronautics Authority (CAA), and gave the new agency power to regulate airline tariffs, airmail rates, interline agreements, mergers, and airline routes. Its mission was to preserve order in the industry, holding rates to reasonable levels while at the same time nurturing the still financially-shaky airline industry by protecting carriers from unbridled competition.
Congress created a separate agency - the Air Safety Board - to regulate the carriers on matters of safety. In 1940, however, President Roosevelt convinced Congress to transfer the safety regulatory function to the CAA, which was then renamed the Civil Aeronautics Board (CAB). These moves, coupled with the tremendous progress made on the technological side, put the industry firmly on the road to success.
World War II
Aviation had an enormous impact on the course of World War II and the war had just as big of an impact on aviation. There were fewer than 300 air transports in the United States when Hitler marched into Poland in 1939. By the end of the war, U.S. aircraft manufacturers were producing 50,000 planes a year!
Most of the planes, of course, were fighters and bombers, but the importance of air transports to the war effort quickly became apparent as well. Throughout the war, the airlines provided much needed airlift to keep people and supplies moving to the front and throughout the production chain back home. For the first time in their history, the airlines had far more business - for passengers as well as freight - than they could handle. Many of them also had opportunities to pioneer new routes, gaining an exposure that would give them a decidedly broader outlook at war's end.
While there were numerous advances in U.S. aircraft design during the war that enabled planes to go faster, higher, and further than ever before, mass production was the chief goal of the United States. The major innovations of the wartime period - radar and jet engines - occurred in Europe.
The Jet Engine
Isaac Newton was the first to theorize (in the 18th century) that a rearward-channeled explosion could propel a machine forward at a great rate of speed. However, no one found a practical application for the theory until Frank Whittle, a British pilot, designed the first jet engine in 1930. Even then, widespread skepticism about the commercial viability of a jet prevented Whittle's design from being tested for several years.
The Germans were the first to actually build and test a jet aircraft. Based on a design by Hans von Ohain, a student working independent of Whittle, it flew in 1939, although not as well as the Germans had hoped. It would take another five years for German scientists to perfect the design, by which time it was too late to affect the outcome of the war.
Whittle also improved his jet engine during the war, and in 1942 he shipped an engine prototype to General Electric in the United States. America's first jet plane was built the following year.
Radar
A technological development with a much greater impact on the war's outcome (and later on commercial aviation) was radar. British scientists had been working on a device that could give them early warning of approaching enemy aircraft even before the war began, and by 1940 Britain had a line of radar transceivers along its east coast that could detect German aircraft the moment they took off from the Continent.
British scientists also perfected the cathode ray oscilloscope, which produced map-type outlines of surrounding countryside and showed aircraft as a pulsing light. Americans, meanwhile, found a way to distinguish between enemy aircraft and Allied aircraft by installing transponders aboard the later that signaled their identity to radar operators.
Dawn of the Jet Age
Aviation was poised to advance rapidly following the war, in large part because of the development of jets, but there still were significant problems to overcome. In 1952 a 36-seat British-made jet called the Comet flew from London to Johannesburg, South Africa, at speeds as high as 500 miles per hour. Two years later, the Comet's career ended abruptly following two back-to-back accidents in which the fuselage burst apart during flight - the result of metal fatigue caused by repeated pressurization cycles.
The cold war between the Soviet Union and the United States following World War II helped secure the funding needed to solve such problems and advance the jet's development. Most of the breakthroughs related to military aircraft that later were applied to the commercial sector. For example, Boeing employed a swept-back wing design for its B-47 and B-52 bombers to reduce drag and increase speed. Later, the design was incorporated into commercial jets, making them faster and thus more attractive to passengers. The best example of military-civilian technology transfer was the jet tanker Boeing designed for the Air Force to refuel bombers in flight, thus extending their range. The tanker, called the KC- 135, was a huge success as a military plane but even more successful when revamped and introduced in 1958 as the first U.S. passenger jet, the Boeing 707. With a length of 125 feet and four engines with 17,000 pounds of thrust, the 707 could carry up to 181 passengers and travel at speeds as high as 550 miles per hour. Its engines proved more reliable than piston driven engines, and they produced less vibration, putting less stress on the plane's airframe and reducing maintenance expenses. They also burned kerosene, which cost half as much as the high octane gasoline used in more traditional planes. With the 707, first ordered and operated by Pan Am, all questions about the commercial feasibility of jets were answered. The jet age had arrived, and other airlines soon were lining up to buy the new aircraft.
The Federal Aviation Act of 1958
Following World War II, air travel soared, but with the industry's growth came new problems. In 1956 two aircraft collided over the Grand Canyon and 128 people were killed. The skies were getting too crowded for existing systems of aircraft separation, and Congress responded by passing the Federal Aviation Act in 1958.
The legislation created a new safety regulatory agency, the Federal Aviation Agency, later called the Federal Aviation Administration when Congress created the Department of Transportation in 1967. The agency was charged with establishing and running a broad air traffic control system to maintain safe separation of all commercial aircraft through all phases of flight. In addition, it assumed jurisdiction over all other aviation safety matters, such as the certification of aircraft designs, and airline training and maintenance programs. The Civil Aeronautics Board retained jurisdiction solely over economic matters, such as airline routes and rates.
Widebodies and Supersonics
1969 marked the debut of another revolutionary aircraft, the Boeing 747, which Pan Am was the first to purchase and fly in commercial service. It was the first widebody jet, with two aisles, a distinctive upper deck over the front section of the fuselage, and four engines under its wings. With seating for as many as 450 passengers, it was twice as big as any other Boeing jet and 80% bigger than the largest jet up until that time, the DC-8.
Recognizing the economies of scale to be gained from larger jets, other aircraft manufacturers quickly followed suit. Douglas built its first widebody, the DC-10, in 1970, and only a month later, Lockheed flew its contender in the widebody market, the L-1011. Both of these jets had three engines (one under each wing and one on the tail) and were smaller than the 747, seating about 250 passengers.
During the same period of time, efforts were underway in both the United States and Europe to build a supersonic commercial aircraft. The Soviet Union was the first to succeed, testing the Tupolev 144 in December of 1968. A consortium of West European aircraft manufacturers first flew the Concorde two months later and eventually produced a number of those fast, but small, jets for commercial service. U.S. efforts to produce a supersonic passenger jet, on the other hand, foundered in 1971 due to public concern about the sonic boom produced by such aircraft. U.S. airlines have never operated a supersonic aircraft.
منقول من احد المواقع
أحمد مسعد
Ahmed Mosaad_ATC14- Silver Captian
- عدد الرسائل : 94
العمر : 37
تاريخ التسجيل : 07/05/2008 -
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