Tuesday, 29 March 2011





THE IMPORTANCE OF WATER

With two thirds of the earth's surface covered by water and the human body consisting of 75 percent of it, it is evidently clear that water is one of the prime elements responsible for life on earth. Water circulates through the land just as it does through the human body, transporting, dissolving, replenishing nutrients and organic matter, while carrying away waste material. Further in the body, it regulates the activities of fluids, tissues, cells, lymph, blood and glandular secretions.

An average adult body contains 42 litres of water and with just a small loss of 2.7 litres he or she can suffer from dehydration, displaying symptoms of irritability, fatigue, nervousness, dizziness, weakness, headaches and consequently reach a state of pathology. Dr F. Batmanghelidj, in his book 'your body's many cries for water', gives a wonderful essay on water and its vital role in the health of a water 'starved' society. He writes: "Since the 'water' we drink provides for cell function and its volume requirements, the decrease in our daily water intake affects the efficiency of cell activity........as a result chronic dehydration causes symptoms that equal disease..."

THE HISTORY OF WATER

Water has been used since antiquity as a symbol by which to express devotion and purity. Some cultures, like the ancient Greeks, went as far as to worship gods who were thought to live in and command the waters. Whole cities have been build by considering the location and availability of pure drinking water. The place of gathering was around the wells, which is perhaps the following trend in building fountains in the middle of piazzas.

Traditional and modern medicine have been makings use of the psychological and physiological diverse properties of water, in all forms of hydrotherapy (composite Greek word: hydro, of water and therapy, . We all know of the simple, yet effective, calming qualities of a warm bath or the invigorating qualities of a cold shower. For centuries, numerous healing springs located all around the world have been recognised for their benefits. The famous Belgium spas in the Ardennes is a fine example. Historical records of these cold springs claim 'cures' since the fourteenth century. The hot Californian spas, the healing spas of Loutraki in Greece, the Dalhousie hot springs in the border of South Australia and Northern Territory, Moree in NSW, Hepburn mineral spas in Victoria are just a few examples.

OUR WATER TODAY

Contrary to the past, our recent developed technological society has become indifferent to this miracle of life. Our natural heritage (rivers, seas and oceans) has been exploited, mistreated and contaminated.

The population decline of the marine and riparian life, the appearance of green algae in the rivers and the stench and slime that comes as a result of putrefaction in the water, are clear signs of the depth and extent of disruption that has been caused to this intricate ecosystem (a composite Greek word: eco, home and systema, a combination of things or parts forming a complex or unitary whole). Government bodies and water authorities will have us believe that it is 'safe' and we should not worry about this global alarm. Awareness and action lies entirely upon us, as we need to become our own educators, physicians and innovators. Socrates had once said: "an unexamined life is not worth living....", Jesus took it a step further: "seek, and you shall find......the truth shall set you free..." So questioning everything and anything that anyone tells you until it makes sense, is of uppemost importance. If it is the truth it will feel right, set you free and lead you on the road of discovery and recovery.

THE TRUTH ABOUT THE DRINKING WATER

Our drinking water today, far from being pure, contains some two hundred deadly commercial chemicals. Add to that bacteria, viruses, inorganic minerals (making the water hard) and you have a chemical cocktail that is unsuitable (if not deadly) for human consumption. John Archer in his book 'THE WATER YOU DRINK, HOW SAFE IS IT ?' refers to an estimate of 60,000 tonnes of fifty different chemicals being deliberately added annually to Australia's water. Some of these are:

chlorine: studies1 indicate that chlorine is involved in heart disease, hardening of the arteries (arteriosclerosis), anaemia, high blood pressure, allergies and cancers2 of the bladder, stomach, liver and rectum. Further, chlorine can destroy protein in the body and cause adverse effects on the skin and hair. The US COUNCIL of environmental quality states that cancer risk among people drinking chlorinated water is 93% higher than among those whose water does not contain chlorine". Chlorine binds and reacts with many other chemicals, forming carcinogens like Trihallomethanes3 (THMs), with chloroform being the most common one. Furthermore, recent real life evidence in the tap water of Sydney shows that certain viruses and parasites, like giardia and cryptosporidium, are being resistant to chlorine and can survive the long journey from the sewage treatment to your tap. That makes chlorination a even more pointless and dangerous practice.

Giardia and cryptosporidium are protosoa (unicellular organisms) parasitic to the intestines of animals and humans. Once in the body, these parasites then multiply and cause the respective infections of giardiasis and cryptosporidosis, which contribute or are associated to enteric (intestinal) diseases. Other than food, these parasites are transmited from contaminated drinking water. These infested waters are today in most major cities which is a direct result of the unsuccsessful treatment of recycled sewage effluent. These parasites initially venture their way into the sewage effluent, from Hospitals, abattoir and farms waste, which contain blood, intestines and faeces. While immunocompitend (the ability to develope an immune response) people may remain asymptomatic (presenting no symptons) by ingestion of this parasites, immunocompromised (ie malnutrition Cancer and Aids) patients are at risk. U.S Health Officials estimate 900,000 people each year become ill, and possibly 900 die from waterborne disease4. Notable outbreaks occured in Milwauke, Wisconsin, in 1993 when over 400,000 people became ill after drinking water contaminated with the parasite. Symptoms associated with the infection of this parasites are, mild to profuse debilitating diarrhoea, lassitude, nausea, abdominal pain and vomiting with consequent loss of appetite and fever. The threat and danger of outbreaks similar to the dreaded great London epidemic in 1854 (were cholera due to contaminated water took the life of many unaware citizens) is now once again at our door step and unless drastic precautions are taken on these early sign's we could be expecting disasters of great magnitude (in the apocalipse it states, that one third of the waters will be contaminated, could this be it?). For now it is about time that water authorities admit to their erroneous ways and start looking for alternatives to maintain and preserve water safety and quality. Water is a living substance and as such it needs the same treatment as all other living forms (poisons can not purify). Germany has been for long now pumping oxygen in its rivers and lakes in an attempt to revitalise its nearly dead waters, while Switzerland is experimenting with ozone treatments.

aluminium sulphate: that is added to clarify water, has long been associated with memory loss, possibly Alzheimers disease and is believed to increase cardiovascular disease.

sodium fluoride: this is not a water treatment and was initially added as a supplement to 'assumingly' prevent tooth decay5 in children. Its toxicity is high enough that in larger concentrations can be used as a pesticide and rat killer. In humans it can be damaging to the heart, lungs, liver, cause genetic mutations and have long term negative effects on enzyme production and the efficiency of the immune system. In the medical encyclopedia and dictionary by Miller-Keane, under fluoridation it refers that slight excesses of fluoride are poisonous and it can cause dental fluorosis (mottled discolouration of teeth) and when you look up further down under fluorosis, you can see clearly the irony of the system an enamel hypoplasia resulting from prolonged ingestion of drinking water containing high levels of fluoride". Tests carried out in Victoria in 1976 by the State Water Supply Commission indicated that fluoride is involved in the corrosion of the copper pipes, which causes more poisons leaching into the water. Copper at certain concentrations effects the uptake of essential zinc in the body and can bring on stomach pain, nausea and diarrhoea. Newer office blocks and high stories buildings are more risky, as taps are not regularly used, leaving fluorinated water standing in the copper pipes for longer periods of times, consequently allowing corrosion. As the debate about the safety of fluoride continuous, countries such as Switzerland, Belgium, Holland, Germany and Sweden have terminated its use due to its potential health hazard.

lead: is another chemical ingredient found in the water that imposes risks to the nervous, circulatory and digestive systems. It is a teratogen, a substance known to cause physical defects in the developing embryo. Chronic exposure, even in small doses, may have serious implications to your well being. Symptoms to be wary of are irritability, nervousness, weight loss, anaemia, stomach crumps, constipation and mental depression. The main source of lead in the water is the plumbing and its corrosion.

The list of chemicals continues: sodium sillicofluoride slurry, sulphuric acid, sodium hypochlorite solution, calcium oxide, silt, rust, algae, debris, larvae, asbestos (mostly from corroding cement pipe lines), pesticides, herbicides, fertilisers (from agricultural run offs), moulds, fungi, industrial waste, toxic metals, amoebas, clay and silica have all found their way into the water. As if this is not enough, chemical reactions of the different constituents in our drinking chemical and sewage cocktail make things even worse.

Nitrates from fertilisers when brought in contact with chlorine and ammonia, can turn into nitrites. Nitrites once inside the body combine with amines and form nitrosamines which are highly carcinogenic. Nitrites can interfere with oxygen uptake and since babies are specifically sensitive to this aspect you could not fail to see a possible link between blue baby syndrome and the nitrite factor.

According to studies by the state of California, women who drink tap water have twice as many miscarriages and birth defects as those who have filtering devises or are drinking bottled water. Five studies arrived to the same conclusion, according to State Health, Director Kenneth Kizer. This connection now is such a common knowledge that it even appeared as a passing comment during the movie 'ONE THOUSAND ACRES'.

Inorganic minerals (minerals not suitable for human consumption) such as calcium carbonate, have their effect. Unable to be assimilated they store in between joints, muscles, bones, nerves, inside arteries and become partners in many crippling dis-eases, such as arthritis, hardening of the arteries, gall stones, kidney stones, gout, tinnitus and perhaps even stroke and neuralgia. Dr Paul C. Bragg in his essay and book 'THE SHOCKING TRUTH ABOUT WATER' argues that the human brain and other body structures will become hardened largely through the use of "chemicalized and inorganically mineralised water".

Dr E. Banik, in his book 'THE CHOICE IS CLEAR', explains that inorganic minerals coat the crystalline lens of the eye with a fine film, resulting in cataracts. Glaucoma, the dreadful eye disease, can be another result of hard water. The tiny vessels film up with mineral deposits, which results in a build-up pressure in the eye.

WHAT CHOICES HAVE WE GOT?

Dr Batmanghelidj talks about the shrinking of the vital organs due to insufficient hydration. Dr Bragg postulates how inorganic minerals in water turns people into 'stones' and advises the use of pure water. John Archer alarms of the dangers and condition of public (sewage) water

You are what you drink so make sure what you drink is pure'

Ten years ago the prospect of drinking only purified or bottled water was a fiction, or a novelty for most people. Nowadays, it is becoming a necessity in maintaining and preserving good health. Finding pure water is becoming more than just food for thought and with our brain being 85 percent water, we better start thinking of the choices. It is my opinion and as well of others that tap water should not be drunk at all if other sources are available. However, if tap water is your only option, then boil the water for a few minutes, expose it to the sun for a while in a clear glass container and then aerate it by pouring it back and forth from one container to another. Keep in mind that boiling will only kill bacteria and that harmful chemicals and minerals will still remain in the water. Rain water it is no longer the best available option with today's pollution. Water is a hungry solvent and as the rain falls, it begins to collect hundreds of potentially harmful substances, such as radioactive isotopes and their degradation products of atomic fission including barium, caesium and strontium from world wide atomic experiments and "accidents" which travel around the atmosphere (refer to chart). In addition industrial and exhaust fumes including carbon monoxide, sulphuric acid and lead are collected. That is why the sky looks so clean after a good 'acid' rain.

Spring water contains those unwanted inorganic minerals and their purity is debatable if you consider the pollution of the soil. So use it sparingly or when nothing else is available. Don't be mislead by claims about the value of inorganic minerals, the body cannot make use of any minerals unless they are derived from the plant kingdom (organic minerals). A well balanced diet will provide an abundance of organic minerals that water never could. In his book 'New Life Through Nutrition' nutritionist Dr Shelton Deal debates that we should not look to water as our source of minerals. As for the inexpensive supermarket filters they don't eliminate all impurities and toxins (not that it is claimed that they do).

Reverse osmosis is by far the most advanced technology for home installation available to the public. It is based on the process by which the human cells diffuse fluids between the intracellular and extracellular spaces, by separating and selectively preventing the passage of solute molecules (through a semipermeable membrane) and allowing the passage of the solvent H2O. Through this process almost all harmful bacteria, minerals and toxins are eliminated. Professional installation and surveillance is necessary for if the membrane is ruptured without your knowledge the final condition of the water could be worse than if it were not filtered.

Distilled water, contrary to the wide held view that it leaches organic essential minerals and micronutrients from your body, its emptiness works in your favour. It dissolves and eliminates harmful inorganic minerals and toxic waste accumulation. Once the organic nutrients have been absorbed by the cells they cannot be taken away. Is there an inherent intelligentsia behind all this? The answer is yes! after all, what is the animating factor behind all things? but far from being just an esoteric answer, the key lies in the inherent 'instructions' of the human body's filtering system. The kidneys make sure that nothing valuable will be lost, there is a constant recycling, so even if nutrients were to be 'stolen' they would be returned by the kidneys. Which explains the dark appearance of urine during times of inadequate hydration. Distillation is achieved by boiling the water, steam then rises and is collected in a condenser where it is stored and cooled. The problem in this process is that together with the steam, percentage of the pollutant gases such fluorine and chlorine are also evaporated over into the condenser. To overcome this problem scientists developed other methods like fragmented distillation and C.M.D method (Cold Molecular Distillation) amongst others. C.M.D water is available from companies6 specialising in this area and supply water for medical purposes, allergy affected chemical sensitive people, cancer and dialysis patients (were even small traces of contaminants can send the patient into shock) and generally to any one who is seeking good health. C.M.D water contains no solid matter and is solely consisting of two elements, Hydrogen and Oxygen.

THE AMOUNT OF WATER YOUR BODY NEEDS

Another important factor is the amount of water necessary for our body to function at its peak performance. Bearing in mind again that your body is about 75 percent water it is easy to understand that water must be your body's most essential daily ingredient. Your body looses each day about 2-3 litters of water through elimination, urination, perspiration and respiration. However, this may increase during illness, high performance, exercise, pregnancy and nursing. The beverages most people choose to consume are often counter-productive in promoting hydration. Coffee, tea, alcohol, soft and sugary drinks are all diuretics and will cause not only the loss of water the are dissolved in, but they will also draw water the bodies reserves. In normal conditions your body needs to replace the fluids it has lost throughout the day. Most of fluids should be replaced by drinking pure water. The rest you should get from fruit, vegetables and their juices. Attention must be given that the elderly and children are meeting their daily requirements. Dry mouth is not the only indication of dehydration, in fact it is the last sign. You need to acquire the habit to drink water even when you think you don't need it and eventually your true thirst mechanisms will be reawaken. Signs to look for that identify with dehydration are constipation, headaches, indigestion, weight gain, fluid retention, dark and pungent urine, and their associated pathologies colitis, kidney stones, bladder and urinary track infections to name only a few.

SUMMARY

Water is involved in all bodily functions: digestion, assimilation, elimination, respiration, maintaining temperature (homeostasis) integrity and the strength of all bodily structures. Today, the water is polluted with hundreds of toxins and impurities. Authorities only test for a small number of them. Your body, being primarily water, requires sufficient daily water replacement in order to function efficiently. Water treatments, that are aimed to render our drinking water bacteriologically safe, have been proven ineffective and the presence of certain pathogenic bacteria like giardia and cryptosporidium recently found in Sydney water is just one of the many examples. Viewing the effects of individual chemicals, inorganic minerals and their by-products, you can see a link to today's major diseases. If you drink devitalised, impure water how can you expect vitality and health. Dehydration, due to the offensive taste of the water and the introduction of commercial sugar loaded beverages, has become another contributing factor to dis-ease. The advice of Dr Batmanghelidj to stop treating thirst with medications holds lots of merit. Mineral water may be wonderful to bathe in, however, the presence of inorganic minerals makes it undesirable. Tap water has been proven unsuitable even for showering7. In an article published in the magazine New Scientist, by Ian Anderson 18/9/86, he writes "Showers pose a risk to health". Pure water may become the medicine of the future. 'Oxygen enriched and free of radioactive and chemical compounds' may read on the label of our bottle water in the next millennium.... At this stage Reverse Osmosis and C.M.D water are our best available options.



Add to this our latest Nikken PiMag Living Water System. With FIR, removal of all the nasties, even Gardia and Cryptosporidium, down to .2 microns, replacement of the trace minerals that we are so desparately short of, then the magnetic coil to complete the proccess.





History and Uses of Helicopter

A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine driven rotors. In contrast with fixed-wing aircraft, this allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft would not be able to take off or land. The capability to efficiently hover for extended periods of time allows a helicopter to accomplish tasks that fixed-wing aircraft and other forms of vertical takeoff and landing aircraft cannot perform.

The word 'helicopter' is adapted from the French hélicoptère, coined by Gustave de Ponton d'Amecourt in 1861, which originates from the Greek helix/helik- (ἕλιξ) = "twisted, curved"[and pteron (πτερόν) = "wing".

Helicopters were developed and built during the first half-century of flight, with the Focke-Wulf Fw 61 being the first operational helicopter in 1936. Some helicopters reached limited production, but it was not until 1942 that a helicopter designed by Igor Sikorsky reached full-scale production, with 131 aircraft built. Though most earlier designs used more than one main rotor, it was the single main rotor with antitorque tail rotor configuration of this design that would come to be recognized worldwide as the helicopter.

History

The earliest references for vertical flight have come from China. Since around 400 BC, Chinese children have played with bamboo flying toys, and the 4th-century AD Daoist book Baopuzi (抱朴子 "Master who Embraces Simplicity") reportedly describes some of the ideas inherent to rotary wing aircraft:


da Vinci's "aerial screw"

It was not until the early 1480s, when Leonardo da Vinci created a design for a machine that could be described as an "aerial screw", that any recorded advancement was made towards vertical flight. His notes suggested that he built small flying models, but there were no indications for any provision to stop the rotor from making the whole craft rotate. As scientific knowledge increased and became more accepted, men continued to pursue the idea of vertical flight. Many of these later models and machines would more closely resemble the ancient bamboo flying top with spinning wings, rather than Da Vinci's screw.

Prototype created by M. Lomonosov, 1754

In July 1754, Mikhail Lomonosov demonstrated a small tandem rotor to the Russian Academy of Sciences. It was powered by a spring and suggested as a method to lift meteorological instruments. In 1783, Christian de Launoy, and his mechanic, Bienvenu, made a model with a pair of counter-rotating rotors, using turkey flight feathers as rotor blades, and in 1784, demonstrated it to the French Academy of Sciences. Sir George Cayley, influenced by a childhood fascination with the Chinese flying top, grew up to develop a model of feathers, similar to Launoy and Bienvenu, but powered by rubber bands. By the end of the century, he had progressed to using sheets of tin for rotor blades and springs for power. His writings on his experiments and models would become influential on future aviation pioneers. Alphonse Pénaud would later develop coaxial rotor model helicopter toys in 1870, also powered by rubber bands. One of these toys, given as a gift by their father, would inspire the Wright brothers to pursue the dream of flight.

In 1861, the word "helicopter" was coined by Gustave de Ponton d'Amécourt, a French inventor who demonstrated a small, steam-powered model. While celebrated as an innovative use of a new metal, aluminum, the model never lifted off the ground. D'Amecourt's linguistic contribution would survive to eventually describe the vertical flight he had envisioned. Steam power was popular with other inventors as well. In 1878 Enrico Forlanini's unmanned helicopter was also powered by a steam engine. It was the first of its type that rose to a height of 12 meters (40 ft), where it hovered for some 20 seconds after a vertical take-off. Emmanuel Dieuaide's steam-powered design featured counter-rotating rotors powered through a hose from a boiler on the ground.

In 1885, Thomas Edison was given US$1,000 by James Gordon Bennett, Jr., to conduct experiments towards developing flight. Edison built a helicopter and used the paper for a stock ticker to create guncotton, with which he attempted to power an internal combustion engine. The helicopter was damaged by explosions and one of his workers was badly burned. Edison reported that it would take a motor with a ratio of three to four pounds per horsepower produced to be successful, based on his experiments. Ján Bahýľ, a Slovak inventor, adapted the internal combustion engine to power his helicopter model that reached a height of 0.5 meters (1.6 ft) in 1901. On 5 May 1905, his helicopter reached four meters (13 ft) in altitude and flew for over 1,500 meters (4,900 ft).In 1908, Edison patented his own design for a helicopter powered by a gasoline engine with box kites attached to a mast by cables for a rotor, but it never flew.

First flights

Paul Cornu's helicopter in 1907

In 1906, two French brothers, Jacques and Louis Breguet, began experimenting with airfoils for helicopters and in 1907, those experiments resulted in the Gyroplane No.1. Although there is some uncertainty about the dates, sometime between 14 August and 29 September 1907, the Gyroplane No. 1 lifted its pilot up into the air about two feet (0.6 m) for a minute. However, the Gyroplane No. 1 proved to be extremely unsteady and required a man at each corner of the airframe to hold it steady. For this reason, the flights of the Gyroplane No. 1 are considered to be the first manned flight of a helicopter, but not a free or untethered flight.

That same year, fellow French inventor Paul Cornu designed and built a Cornu helicopter that used two 20-foot (6 m) counter-rotating rotors driven by a 24-hp (18-kW) Antoinette engine. On 13 November 1907, it lifted its inventor to 1 foot (0.3 m) and remained aloft for 20 seconds. Even though this flight did not surpass the flight of the Gyroplane No. 1, it was reported to be the first truly free flight with a pilot. Cornu's helicopter would complete a few more flights and achieve a height of nearly 6.5 feet (2 m), but it proved to be unstable and was abandoned.

The Danish inventor Jacob Ellehammer built the Ellehammer helicopter in 1912. It consisted of a frame equipped with two contra-rotating discs, each of which was fitted with six vanes around its circumference. After a number of indoor tests, the aircraft was demonstrated outdoors and made a number of free take-offs. Experiments with the helicopter continued until September 1916, when it tipped over during take-off, destroying its rotors.

Early development

In the early 1920s, Argentine Raúl Pateras Pescara, while working in Europe, demonstrated one of the first successful applications of cyclic pitch.[5] Coaxial, contra-rotating, biplane rotors could be warped to cyclically increase and decrease the lift they produced. The rotor hub could also be tilted forward a few degrees, allowing the aircraft to move forward without a separate propeller to push or pull it. Pescara was also able to demonstrate the principle of autorotation, by which helicopters safely land after engine failure. By January 1924, Pescara's helicopter No. 3 could fly for up to ten minutes.

Oehmichen N°2 1922

One of Pescara's contemporaries, Frenchman Etienne Oehmichen, set the first helicopter world record recognized by the Fédération Aéronautique Internationale (FAI) on 14 April 1924, flying his helicopter 360 meters (1,181 ft). On 18 April 1924, Pescara beat Oemichen's record, flying for a distance of 736 meters (nearly a half mile) in 4 minutes and 11 seconds (about 8 mph, 13 km/h) maintaining a height of six feet (2 m). Not to be outdone, Oehmichen reclaimed the world record on 4 May when he flew his No. 2 machine again for a 14-minute flight covering 5,550 feet (1.05 mi, 1.69 km) while climbing to a height of 50 feet (15 m). Oehmichen also set the 1 km closed-circuit record at 7 minutes 40 seconds.

In the USA, George de Bothezat built the quadrotor De Bothezat helicopter for the United States Army Air Service but the Army cancelled the program in 1924, and the aircraft was scrapped.

Meanwhile, Juan de la Cierva was developing the first practical rotorcraft in Spain. In 1923, the aircraft that would become the basis for the modern helicopter rotor began to take shape in the form of an autogyro, Cierva's C.4. Cierva had discovered aerodynamic and structural deficiencies in his early designs that could cause his autogyros to flip over after takeoff. The flapping hinges that Cierva designed for the C.4 allowed the rotor to develop lift equally on the left and right halves of the rotor disk. A crash in 1927, led to the development of a drag hinge to relieve further stress on the rotor from its flapping motion. These two developments allowed for a stable rotor system, not only in a hover, but in forward flight.

Albert Gillis von Baumhauer, a Dutch aeronautical engineer, began studying rotorcraft design in 1923. His first prototype "flew" ("hopped" and hovered in reality) on 24 September 1925, with Dutch Army-Air arm Captain Floris Albert van Heijst at the controls. The controls that Captain van Heijst used were Von Baumhauer's inventions, the cyclic and collective. Patents were granted to von Baumhauer for his cyclic and collective controls by the British ministry of aviation on 31 January 1927, under patent number 265,272.

In 1928, Hungarian aviation engineer Oszkár Asbóth constructed a helicopter prototype that took off and landed at least 182 times, with a maximum single flight duration of 53 minutes.

In 1930, the Italian engineer Corradino D'Ascanio built his D'AT3, a coaxial helicopter. His relatively large machine had two, two-bladed, counter-rotating rotors. Control was achieved by using auxiliary wings or servo-tabs on the trailing edges of the blades, a concept that was later adopted by other helicopter designers, including Bleeker and Kaman. Three small propellers mounted to the airframe were used for additional pitch, roll, and yaw control. The D'AT3 held modest FAI speed and altitude records for the time, including altitude (18 m or 59 ft), duration (8 minutes 45 seconds) and distance flown (1,078 m or 3,540 ft).

In the Soviet Union, Boris N. Yuriev and Alexei M. Cheremukhin, two aeronautical engineers working at the Tsentralniy Aerogidrodinamicheskiy Institut (TsAGI, Russian: Центра́льный аэрогидродинами́ческий институ́т (ЦАГИ), English: Central Aerohydrodynamic Institute), constructed and flew the TsAGI 1-EA single rotor helicopter, which used an open tubing framework, a four blade main rotor, and twin sets of 1.8-meter (6-foot) diameter anti-torque rotors; one set of two at the nose and one set of two at the tail. Powered by two M-2 powerplants, up-rated copies of the Gnome Monosoupape rotary radial engine of World War I, the TsAGI 1-EA made several successful low altitude flights. By 14 August 1932, Cheremukhin managed to get the 1-EA up to an unofficial altitude of 605 meters (1,985 ft), shattering d'Ascanio's earlier achievement. As the Soviet Union was not yet a member of the FAI, however, Cheremukhin's record remained unrecognized.

Nicolas Florine, a Russian engineer, built the first twin tandem rotor machine to perform a free flight. It flew in Sint-Genesius-Rode, at the Laboratoire Aérotechnique de Belgique (now von Karman Institute) in April 1933, and attained an altitude of six meters (20 ft) and an endurance of eight minutes. Florine chose a co-rotating configuration because the gyroscopic stability of the rotors would not cancel. Therefore the rotors had to be tilted slightly in opposite directions to counter torque. Using hingeless rotors and co-rotation also minimised the stress on the hull. At the time, it was one of the most stable helicopter in existence.

The Bréguet-Dorand Gyroplane Laboratoire was built in 1933. After many ground tests and an accident, it first took flight on 26 June 1935. Within a short time, the aircraft was setting records with pilot Maurice Claisse at the controls. On 14 December 1935, he set a record for closed-circuit flight with a 500-meter (1,600 ft) diameter. The next year, on 26 September 1936, Claisse set a height record of 158 meters (520 ft). And, finally, on 24 November 1936, he set a flight duration record of one hour, two minutes and 5 seconds over a 44 kilometer (27 mi) closed circuit at 44.7 kilometers per hour (27.8 mph). The aircraft was destroyed in 1943 by an Allied airstrike at Villacoublay airport.

Birth of an industry

First airmail service by helicopter in Los Angeles, 1947

Despite the success of the Gyroplane Laboratoire, the German Focke-Wulf Fw 61, first flown in 1936, would eclipse its accomplishments. The Fw 61 broke all of the helicopter world records in 1937, demonstrating a flight envelope that had only previously been achieved by the autogyro. Nazi Germany would use helicopters in small numbers during World War II for observation, transport, and medical evacuation. The Flettner Fl 282 Kolibri synchropter was used in the Mediterranean, while the Focke Achgelis Fa 223 Drache was used in Europe.[citation needed] Extensive bombing by the Allied forces prevented Germany from producing any helicopters in large quantities during the war.

In the United States, Igor Sikorsky and W. Lawrence LePage were competing to produce the United States military's first helicopter. Prior to the war, LePage had received the patent rights to develop helicopters patterned after the Fw 61, and built the XR-1. Meanwhile, Sikorsky had settled on a simpler, single rotor design, the VS-300. After experimenting with configurations to counteract the torque produced by the single main rotor, he settled on a single, smaller rotor mounted vertically on the tailboom.

Developed from the VS-300, Sikorsky's R-4 became the first mass produced helicopter with a production order for 100 aircraft. The R-4 was the only Allied helicopter to see service in World War II, primarily being used for rescue in Burma, Alaska, and other areas with harsh terrain. Total production would reach 131 helicopters before the R-4 was replaced by other Sikorsky helicopters such as the R-5 and the R-6. In all, Sikorsky would produce over 400 helicopters before the end of World War II.

As LePage and Sikorsky were building their helicopters for the military, Bell Aircraft hired Arthur Young to help build a helicopter using Young's semi-rigid, teetering-blade rotor design, which used a weighted stabilizing bar placed at a 90º angle to the rotor blades. The subsequent Model 30 helicopter showed the design's simplicity and ease of use. The Model 30 was developed into the Bell 47, which became the first helicopter certificated for civilian use in the United States. Produced in several countries, the Bell 47 would stand as the most popular helicopter model for nearly 30 years.

Turbine age

In 1951, at the urging of his contacts at the Department of the Navy, Charles Kaman modified his K-225 helicopter with a new kind of engine, the turboshaft engine. This adaptation of the turbine engine provided a large amount of power to the helicopter with a lower weight penalty than piston engines, with their heavy engine blocks and auxiliary components. On 11 December 1951, the Kaman K-225 became the first turbine-powered helicopter in the world. Two years later, on 26 March 1954, a modified Navy HTK-1, another Kaman helicopter, became the first twin-turbine helicopter to fly. However, it was the Sud Aviation Alouette II that would become the first helicopter to be produced with a turbine-engine.

Reliable helicopters capable of stable hover flight were developed decades after fixed-wing aircraft. This is largely due to higher engine power density requirements than fixed-wing aircraft. Improvements in fuels and engines during the first half of the 20th century were a critical factor in helicopter development. The availability of lightweight turboshaft engines in the second half of the 20th century led to the development of larger, faster, and higher-performance helicopters. While smaller and less expensive helicopters still use piston engines, turboshaft engines are the preferred powerplant for helicopters today.

Uses

Due to the operating characteristics of the helicopter—its ability to takeoff and land vertically, and to hover for extended periods of time, as well as the aircraft's handling properties under low airspeed conditions—it has been chosen to conduct tasks that were previously not possible with other aircraft, or were time- or work-intensive to accomplish on the ground. Today, helicopter uses include transportation, construction, firefighting, search and rescue, and military uses.

A helicopter used to carry loads connected to long cables or slings is called an aerial crane. Aerial cranes are used to place heavy equipment, like radio transmission towers and large air conditioning units, on the tops of tall buildings, or when an item must be raised up in a remote area, such as a radio tower raised on the top of a hill or mountain. Helicopters are used as aerial cranes in the logging industry to lift trees out of terrain where vehicles cannot travel and where environmental concerns prohibit the building of roads. These operations are referred to as longline because of the long, single sling line used to carry the load.

Helitack is the use of helicopters to combat wildland fires. The helicopters are used for aerial firefighting (or water bombing) and may be fitted with tanks or carry helibuckets. Helibuckets, such as the Bambi bucket, are usually filled by submerging the bucket into lakes, rivers, reservoirs, or portable tanks. Tanks fitted onto helicopters are filled from a hose while the helicopter is on the ground or water is siphoned from lakes or reservoirs through a hanging snorkel as the helicopter hovers over the water source. Helitack helicopters are also used to deliver firefighters, who rappel down to inaccessible areas, and to resupply firefighters. Common firefighting helicopters include variants of the Bell 205 and the Erickson S-64 Aircrane helitanker.

Helicopters are used as air ambulances for emergency medical assistance in situations when an ambulance cannot easily or quickly reach the scene. Helicopters are also used when a patient needs to be transported between medical facilities and air transportation is the most practical method for the safety of the patient. Air ambulance helicopters are equipped to provide medical treatment to a patient while in flight. The use of helicopters as an air ambulance is often referred to as MEDEVAC, and patients are referred to as being "airlifted", or "medevaced".

Police departments and other law enforcement agencies use helicopters to pursue suspects. Since helicopters can achieve a unique aerial view, they are often used in conjunction with police on the ground to report on suspects' locations and movements. They are often mounted with lighting and heat-sensing equipment for night pursuits.

Military forces use attack helicopters to conduct aerial attacks on ground targets. Such helicopters are mounted with missile launchers and miniguns. Transport helicopters are used to ferry troops and supplies where the lack of an airstrip would make transport via fixed-wing aircraft impossible. The use of transport helicopters to deliver troops as an attack force on an objective is referred to as Air Assault. Unmanned Aerial Systems (UAS) helicopter systems of varying sizes are being developed by companies for military reconnaissance and surveillance duties. Naval forces also use helicopters equipped with dipping sonar for anti-submarine warfare, since they can operate from small ships.

Oil companies charter helicopters to move workers and parts quickly to remote drilling sites located out to sea or in remote locations. The speed over boats makes the high operating cost of helicopters cost effective to ensure that oil platforms continue to flow. Various companies specialize in this type of operation.

Other uses of helicopters include, but are not limited to:

  • Aerial photography
  • Motion picture photography
  • Electronic news gathering
  • Reflection seismology
  • Search and Rescue
  • Tourism or recreation
  • Transport

Design features

Basic anatomy of a Helicopter

Rotor system

The rotor system, or more simply rotor, is the rotating part of a helicopter which generates lift. A rotor system may be mounted horizontally as main rotors are, providing lift vertically, or it may be mounted vertically, such as a tail rotor, to provide lift horizontally as thrust to counteract torque effect. The rotor consists of a mast, hub and rotor blades.

A semirigid rotor system

The mast is a cylindrical metal shaft which extends upwards from and is driven by the transmission. At the top of the mast is the attachment point for the rotor blades called the hub. The rotor blades are then attached to the hub by a number of different methods. Main rotor systems are classified according to how the main rotor blades are attached and move relative to the main rotor hub. There are three basic classifications: rigid, semirigid, or fully articulated, although some modern rotor systems use an engineered combination of these types.

Antitorque configurations

MD Helicopters 520N NOTAR

Most helicopters have a single main rotor, but torque created as the engine turns the rotor against its air drag causes the body of the helicopter to turn in the opposite direction to the rotor. To eliminate this effect, some sort of antitorque control must be used. The design that Igor Sikorsky settled on for his VS-300 was a smaller rotor mounted vertically on the tail. The tail rotor pushes or pulls against the tail to counter the torque effect, and has become the recognized convention for helicopter design. Some helicopters utilize alternate antitorque controls in place of the tail rotor, such as the ducted fan (called Fenestron or FANTAIL), and NOTAR. NOTAR provides antitorque similar to the way a wing develops lift, through the use of a Coandă effect on the tailboom.

The use of two or more horizontal rotors turning in opposite directions is another configuration used to counteract the effects of torque on the aircraft without relying on an antitorque tail rotor. This allows the power normally required to drive the tail rotor to be applied to the main rotors, increasing the aircraft's lifting capacity. Primarily, there are three common configurations that use the counterrotating effect to benefit the rotorcraft. Tandem rotors are two rotors with one mounted behind the other. Coaxial rotors are two rotors that are mounted one above the other with the same axis. Intermeshing rotors are two rotors that are mounted close to each other at a sufficient angle to allow the rotors to intermesh over the top of the aircraft. Transverse rotors is another configuration found on tiltrotors and some earlier helicopters, where the pair of rotors are mounted at each end of the wings or outrigger structures. Tip jet designs permit the rotor to push itself through the air, and avoid generating torque.

Engines

The number, size and type of engine used on a helicopter determines the size, function and capability of that helicopter design. The earliest helicopter engines were simple mechanical devices, such as rubber bands or spindles, which relegated the size of helicopters to toys and small models. For a half century before the first airplane flight, steam engines were used to forward the development of the understanding of helicopter aerodynamics, but the limited power did not allow for manned flight. The introduction of the internal combustion engine at the end of the 19th century became the watershed for helicopter development as engines began to be developed and produced that were powerful enough to allow for helicopters able to lift humans.

Early helicopter designs utilized custom-built engines or rotary engines designed for airplanes, but these were soon replaced by more powerful automobile engines and radial engines. The single, most-limiting factor of helicopter development during the first half of the 20th century was that the amount of power produced by an engine was not able to overcome the engine's weight in vertical flight. This was overcome in early successful helicopters by using the smallest engines available. When the compact, flat engine was developed, the helicopter industry found a lighter-weight powerplant easily adapted to small helicopters, although radial engines continued to be used for larger helicopters.

Turbine engines revolutionized the aviation industry, and the turboshaft engine finally gave helicopters an engine with a large amount of power and a low weight penalty. The turboshaft engine was able to be scaled to the size of the helicopter being designed, so that all but the lightest of helicopter models are powered by turbine engines today.

Special jet engines developed to drive the rotor from the rotor tips are referred to as tip jets. Tip jets powered by a remote compressor are referred to as cold tip jets, while those powered by combustion exhaust are referred to as hot tip jets. An example of a cold jet helicopter is the Sud-Ouest Djinn, and an example of the hot tip jet helicopter is the YH-32 Hornet.

Some radio-controlled helicopters and smaller, helicopter-type unmanned aerial vehicles, use electric motors. Radio-controlled helicopters may also have piston engines that use fuels other than gasoline, such as Nitromethane. Some turbine engines commonly used in helicopters can also use biodiesel instead of jet fuel.

Flight controls


Cockpit of an Alouette III

A helicopter has four flight control inputs. These are the cyclic, the collective, the anti-torque pedals, and the throttle. The cyclic control is usually located between the pilot's legs and is commonly called the cyclic stick or just cyclic. On most helicopters, the cyclic is similar to a joystick. However, the Robinson R22 and Robinson R44 have a unique teetering bar cyclic control system and a few helicopters have a cyclic control that descends into the cockpit from overhead.

The control is called the cyclic because it changes the pitch of the rotor blades cyclically. The result is to tilt the rotor disk in a particular direction, resulting in the helicopter moving in that direction. If the pilot pushes the cyclic forward, the rotor disk tilts forward, and the rotor produces a thrust in the forward direction. If the pilot pushes the cyclic to the side, the rotor disk tilts to that side and produces thrust in that direction, causing the helicopter to hover sideways.

The collective pitch control or collective is located on the left side of the pilot's seat with a settable friction control to prevent inadvertent movement. The collective changes the pitch angle of all the main rotor blades collectively (i.e. all at the same time) and independently of their position. Therefore, if a collective input is made, all the blades change equally, and the result is the helicopter increasing or decreasing in altitude.

The anti-torque pedals are located in the same position as the rudder pedals in a fixed-wing aircraft, and serve a similar purpose, namely to control the direction in which the nose of the aircraft is pointed. Application of the pedal in a given direction changes the pitch of the tail rotor blades, increasing or reducing the thrust produced by the tail rotor and causing the nose to yaw in the direction of the applied pedal. The pedals mechanically change the pitch of the tail rotor altering the amount of thrust produced.

Helicopter rotors are designed to operate in a narrow range of RPM.[38][39][40][41] The throttle controls the power produced by the engine, which is connected to the rotor by a fixed ratio transmission. The purpose of the throttle is to maintain enough engine power to keep the rotor RPM within allowable limits in order to keep the rotor producing enough lift for flight. In single-engine helicopters, the throttle control is a motorcycle-style twist grip mounted on the collective control, while dual-engine helicopters have a power lever for each engine.

A Swashplate transmits the pilot commands to the main rotor blades for articulated rotors.

Flight conditions

There are two basic flight conditions for a helicopter; hover and forward flight.

Svalbard helicotper.ogv
Helicopter hovering over boat in rescue exercise
  • Hover
Hovering is the most challenging part of flying a helicopter. This is because a helicopter generates its own gusty air while in a hover, which acts against the fuselage and flight control surfaces. The end result is constant control inputs and corrections by the pilot to keep the helicopter where it is required to be. Despite the complexity of the task, the control inputs in a hover are simple. The cyclic is used to eliminate drift in the horizontal plane, that is to control forward and back, right and left. The collective is used to maintain altitude. The pedals are used to control nose direction or heading. It is the interaction of these controls that makes hovering so difficult, since an adjustment in any one control requires an adjustment of the other two, creating a cycle of constant correction.
  • Forward flight
In forward flight a helicopter's flight controls behave more like that in a fixed-wing aircraft. Displacing the cyclic forward will cause the nose to pitch down, with a resultant increase in airspeed and loss of altitude. Aft cyclic will cause the nose to pitch up, slowing the helicopter and causing it to climb. Increasing collective (power) while maintaining a constant airspeed will induce a climb while decreasing collective will cause a descent. Coordinating these two inputs, down collective plus aft cyclic or up collective plus forward cyclic, will result in airspeed changes while maintaining a constant altitude. The pedals serve the same function in both a helicopter and a fixed-wing aircraft, to maintain balanced flight. This is done by applying a pedal input in whichever direction is necessary to center the ball in the turn and bank indicator.
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