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CHAPTER 1 PERSONNEL PARACHUTE FAMILIARIZATION Learning Objective: Upon completion of this chapter, you will be able to recognize and understand the history, components, and publications used to maintain personnel emergency parachute assemblies. The word parachute is, in the modern sense, derived from the Italian word parare, meaning to protect or shield from, and the French word chute, meaning a fall or quick descent-literally, "to protect from a fall." As early as the year 1300, Chinese experimenters are reported to have jumped off the Great Wall with devices resembling umbrellas. In the year 1495, the great genius, artist, and inventor, Leonardo da Vinci, sketched a parachute design to be made of caulked linen that would permit a gentle descent to earth. About a century later, Fausto Veranzio described and sketched a parachute design consisting of a four-poled square frame covered with fabric, which he claimed could be used to escape from tall, burning buildings. Since man, not yet airborne, had no use for a lifesaving device of this nature at that time, parachutes were considered novelties or items of amusement, and interest in them gradually lessened. It was not until the invention of the first aerial balloon that interest in the parachute was renewed. As a result of the balloon, the parachute became less of a toy and more a means of escape. In the late 1700's, the Montgolfier brothers had invented a balloon that would stay aloft. This balloon was kept in the air by burning bundles of straw beneath the bag to furnish the necessary supply of hot air. If the fabric caught fire, the flight was abruptly ended. This meant that those who went up on such flights had to have a means of escape. Those early days of ballooning saw excursions of curiosity into the use of parachutes by early balloonists such as the Montgolfiers, Blanchard, Martyn, Arnold, Appleby, Hampton, and others. Some parachute drops, using animals as passengers, were successfully made. The first human parachute descent was accomplished by the famous French balloonist Andre-Jacques Garnerin, on 22 October 1798. This historic event took place over Monceau Park, near Paris, when Garnerin released himself and his semirigid parachute from the balloon at an altitude of 6,000 feet. On 14 July 1808, a famous Polish balloonist, Jodaki Kuparento, was the first man to have his life saved from a flaming bag of hot air when, over Warsaw, remnants of his burning balloon blew into the balloon's net structure and blossomed into a parachute, lowering him to the ground safely. However, the need for a foolproof parachute-whose main role at that time was its use as an added thrill to balloon ascensions-was not strong enough to stimulate a great deal of inventive effort until nearly 100 years later. Hence, with the coming of the air age in 1903, when the Wright brothers made their spectacular flight at Kitty Hawk, North Carolina, there came also an era of experimentation with parachutes designed for this new type of flying machine. Albert Berry is credited with being the first person to successfully jump from an aircraft using a parachute. This jump was made on March 1, 1912, from a Benoist Pusher Biplane, at Jefferson Barracks, not far from Kinloch Park "Aerodrome," St. Louis. The parachute was an unbleached muslin cotton parachute, 36 feet in diameter. Its suspension lines terminated into a trapeze bar and strap arrangement. The parachute assembly was packed into a cone attached under the airplane. It was retained within the metal cone by a series of break cords. The weight of Berry's falling body pulled the canopy and lines from the container. Many others, using makeshift or experimental parachutes, made descents before World War I, but parachutes still were not considered essential equipment for military aviators. As World War I progressed, the resultant mortality rate among pilots was very high. However, the lives of over 800 balloonist observers and artillery fire directors were saved by parachutes, demonstrating a desperate need for a foolproof and practical lifesaving device for aviators. The next step was to improve parachute reliability and make them mandatory for military fliers. Parachute lore tells us that in 1917 a French pilot attacked a German Fokker and riddled it with bullets. The plane exploded in flames and began to plunge to earth. As the Frenchman circled his kill, he was surprised to see the enemy pilot jump, immediately followed by a ribbon of white swing out behind him as he fell through the clouds. Still amazed, he watched as a great billowing canopy fluttered and opened. The plummeting body slowed with a jerk and began swaying gently beneath the air-filled blossom. The adversary waved at the stunned victor and proceeded to swing into no man's land, where the reception was far from friendly. Twenty-seven rifle and machine gun bullets were pumped into the German's legs. He survived and gained the honor of being the first person to save his life by an emergency escape from an airplane. Official documentation reveals that regular emergency bailouts were made during the late months of 1918 by German aviators. Captured equipment showed the parachute to be a unique one designed by Heineke. Gradually, German fighter pilots began to equip themselves with parachutes. Soon, whole squadrons were doing the same. At the end of the war, it was reported that all fliers in the entire German Air Force were in the process of wearing parachutes in flight. All parachutes, however clever in design, were still dependent upon a static line attached to the aircraft to deploy the parachute, and they were far from perfect. Thus, some emergency escape attempts continued to take lives. Towards the end of 1918, with the war coming to a close, demands by the flying public and Congress finally resulted in the formation of a U.S. Air Service Parachute Board at McCook Field in Dayton, Ohio. Floyd Smith, with a reputation for his ideas in parachute design, was put in charge of this new unit of the Engineering Division. He surrounded himself with Guy M. Ball, James M. Russel, James J. Higgins, and Sgt. Ralph W. Bottreil. At the beginning of 1919, energetic Major E. L. Hoffman was chosen as military head of this parachute development team. The "crash program" produced results. Parachutes from all over the world, all attached (static-line actuated) types, were tested and found to be unsafe and weak, and otherwise unsuitable for use in emergency jumps from airplanes. Initial testing on a new parachute design devised by Floyd Smith showed potential. This concept involved the use of a parachute canopy and lines packed into a container worn on a body harness, using a manually operated ripcord, yanked while falling freely through the air with no attachment to the aircraft, to open the parachute. Floyd Smith, with Guy Ball working closely at his side, worked together to perfect this new revolutionary parachute. This parachute ultimately became the U.S. Air Service Airplane Parachute, type A. It had a 28-foot diameter silk canopy with silk suspension lines. The canopy was formed of 40 gores, with a novel shock-reducing vent design, and it was packed into a backpack container worn on the body of the flyer, by being attached to a webbing harness. A small pilot-chute was used to deploy the packed canopy and lines into the air when a pull on the ripcord opened the flaps on the back container being worn on the body. Not being dependent on any attachment to the aircraft for operation, it allowed the aviator to leave his disabled aircraft regardless of its position. It was capable of withstanding an opening shock delivered by 200 pounds falling at a speed of 400 miles per hour. When Major Hoffman felt that it was time for the Model A parachute to be live-jumped, he chose a young, enthusiastic parachutist and designer named Leslie L. Irvin because of his vast experience as a parachute jumper. Irvin had responded to the government's call for a suitable parachute, and submitted a static-line operated parachute assembly with a cotton canopy. He was apprised that the submitted parachute was unsuitable because by that time the use of a silk canopy, as well as the ripcord concept, was considered preferable. Irvin continued to cooperate with the board by supplying parachute items. On April 28th, 1919, flying in a USD-9 airplane piloted by Floyd Smith at an altitude of 1,500 feet and airspeed of 80 miles per hour, Irvin jumped from its turret cockpit wearing a prototype Model A chute. He pulled the ripcord, the parachute opened in one and two-fifth seconds, and he became the first man to make a free-fall parachute jump from an aircraft. The new parachute was the first step on the way to all modern personnel parachutes-emergency, military, and sporting. From this basic design came the seat pack, chest or reserve chutes, backpacks, and any other parachute that can be attached to a harness. In October 1922, Lieutenant Harold Harris, U.S. Army, was dramatically saved from death by using a manually-operated parachute when his aircraft failed. By March 1924, it became mandatory for all Army and Navy aircrew to wear the standard back-type parachute while in flight. A sign in one of the parachute lofts read, "Don't forget your parachute. If you need it and you haven't got it, you'll never need it again." With the requirement for all Navy aviators to wear parachutes, the necessity for trained personnel to pack and maintain these parachutes became apparent. In June 1922, the Bureau of Aeronautics requested volunteers from among the petty officers attached to the various naval air stations to take a course of instruction in parachutes at the Army School at Chanute Field, Rantoul, Illinois. Thirteen chief petty officers were selected from throughout the Navy. They completed the course of instruction and returned to their duty stations. Three of them were selected for further training at McCook Field, Dayton, Ohio, at that time the Army Equipment Experimental Depot. The three chief petty officers received advanced training in parachutes. In August 1923, Chief Alva Starr and Chief Lyman Ford, two of the three, were ordered to Lakehurst, New Jersey, to set up a training course on parachutes. Although the course was established, the PR rate was not established until 1942. In September 1924, class No. 1 was convened at the Parachute Material School at Lakehurst to teach parachute rigging. Although his name is now lost to history, one of the farsighted founders of the PR school decided on a novel means to help combat the airmen's reluctance to "hit the silk." He reasoned that if it became known that the men who packed and repaired the parachutes had enough confidence in their ability and equipment to make a deliberate, premeditated jump, the aviator might be more willing to take a chance on his parachute than to crash in his airplane. In the beginning, graduate trainees jumped from the outer wing tips of a biplane flying high above the naval air station at Lakehurst. Later, the students "let go" from short rope ladders suspended from the sides of the old gondola airships (blimps), and later still, from training and patrol type lighter-than-air ships. Since the beginning of the PR school in 1924, there have been over 72,000 parachute jumps made at Lakehurst, New Jersey. With the coming of the jet age, the emergency use of parachutes has become a highly technical sequence; that is, events in time order. Today's emergency sequence for ejecting from a disabled aircraft starts with the aircrewman making a decision to leave the aircraft. After making that decision everything is done automatically, as you will see in the ejection sequence for the A-6 aircraft, shown in figure 1-1. This is only one of
Figure 1-1.-Ejection sequence. 1-3
Figure 1-2.-Aircraft egress, pilot chute deployed, and main canopy free of container. several types of ejection systems used in modern naval aircraft. For example, the ejection sequence of the Mk GRU-7 is as follows: 1. Initial ejection. 2. Drogue gun fires. 3. Controller drogue deploys. 4. Stabilizer drogue deploys. 5. Main parachute deploys and a normal parachute descent is made. From the experimental devices of the early Chinese through the seat ejection systems of today, you can view the evolution of the parachute. If you consider this development as a window through which you can see solutions to the escape problems of the fliers of the space shuttle or other advanced craft, then this history is just the end of the beginning. A parachute appears somewhat similar to a giant umbrella. By offering a large air-resisting or drag surface, the parachute, when opened, provides the deceleration necessary to allow for the safe descent of an aircrewman. In each parachute jump a sequence of events, shown in figure 1-2, takes place. After the parachutist clears the aircraft, he pulls the ripcord. The ripcord pins are removed from the locking cones, permitting the grommets to separate from the locking cones. The container spring opening bands pull the side and end flaps apart allowing the pilot chute to spring beyond the negative pressure area immediately above the falling body. This results in its getting a better "bite" on the surrounding air, thus speeding the opening of the canopy. The aircrewman falling away from the pilot parachute causes the main canopy to be pulled from the container assembly, followed by the suspension lines. The canopy begins to fill with air during this operation. The ties on the risers break as the load is applied. The lift webs are then pulled from the container while the canopy fully opens; at this point the parachutist receives the opening shock as the parachute fills with air. The aircrewman then hangs or sits suspended in the harness during the descent. There are many different types of parachutes used in today's naval aircraft. To really understand the operating principles of a parachute, you should first know the basic design and construction of a parachute and its components. |
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