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Helicopter
An LAPD Bell 206
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.A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine driven rotors.^ These helicopters are different from the A-stars in that they have bucket seats, even more viewing glass area and a quieter engine so it is not heard so easily from the ground.
  • Maui Helicopter Tour in Maui Hawaii Helicopters Tours Rides 7 January 2010 13:56 UTC www.tombarefoot.com [Source type: General]

.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.^ There is a refreshing lack of restrictions of flying and landing helicopters within Panama.

^ I have held a commercial fixed wing (light aircraft) in both NZ and Australia but both are lapsed some years now.

^ I can take off from a bar stool, fly around the room, hover over my head and land in the palm of my hand.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

.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.^ I have held a commercial fixed wing (light aircraft) in both NZ and Australia but both are lapsed some years now.

^ I can take off from a bar stool, fly around the room, hover over my head and land in the palm of my hand.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

^ These helicopters are different from the A-stars in that they have bucket seats, even more viewing glass area and a quieter engine so it is not heard so easily from the ground.
  • Maui Helicopter Tour in Maui Hawaii Helicopters Tours Rides 7 January 2010 13:56 UTC www.tombarefoot.com [Source type: General]

.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.^ I have held a commercial fixed wing (light aircraft) in both NZ and Australia but both are lapsed some years now.

^ My fixed wing experience allowed me to concentrate more on actually flying the aircraft as opposed to trying to take in instruments, radio etc.

^ FAR 91.119 says "Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes..."

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- (ἕλικ-) = 'spiral' or 'turning' and pteron (πτερόν) = 'wing'.[1][2]
.Helicopters were developed and built during the first half-century of flight, with some reaching limited production, but it was not until 1942 that a helicopter designed by Igor Sikorsky reached full-scale production,[3] with 131 aircraft built.^ When they first came they flew the Robinson R44 aircraft which was an excellent tour for people who wanted private flights for just 2 in a helicopter.
  • Maui Helicopter Tour in Maui Hawaii Helicopters Tours Rides 7 January 2010 13:56 UTC www.tombarefoot.com [Source type: General]

^ While helicopter flight school instruction is one aspect of our program, we emphasize professional development to make our customers employable.
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

^ For $1000, you can buy a full size RC heli and crash it hard the first flight and game over!
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

[4] .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.^ The McDonnell-Douglas Notar is designed without a tail rotor, giving a noticeably quieter flight.
  • Maui Helicopter Tour in Maui Hawaii Helicopters Tours Rides 7 January 2010 13:56 UTC www.tombarefoot.com [Source type: General]

^ Keep in mind however that you won't be seeing anything different than you would in the A-Star but perhaps in a bit more deluxe manner.
  • Maui Helicopter Tour in Maui Hawaii Helicopters Tours Rides 7 January 2010 13:56 UTC www.tombarefoot.com [Source type: General]

^ You'd expect helicopters to be vastly more dangerous than airplanes.

Contents

History

The earliest references for vertical flight have come from China. Since 400 BC,[5] Chinese children have played with bamboo flying toys[6][7] and a book written in 4th-century China, referred to as Pao Phu Tau (also Pao Phu Tzu or Bao Pu Zi, 抱朴子), is reported to describe some of the ideas inherent to rotary wing aircraft:[8]
Someone asked the master about the principles of mounting to dangerous heights and traveling into the vast inane. The Master said, "Some have made flying cars with wood from the inner part of the jujube tree, using ox-leather [straps] fastened to returning blades so as to set the machine in motion."[9]
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.^ Old school helicopter pilots will scoff at the R22 for a variety of reasons, including the low inertia rotor system, but there is no low-cost alternative.

^ Mind that this tweak will make flying backwards even more unstable than it already is, because even more air will be blown into the main rotor.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

^ The rotator shaft does not come between the front and back seats and there are no visual impediments interrupting your view forward.
  • Maui Helicopter Tour in Maui Hawaii Helicopters Tours Rides 7 January 2010 13:56 UTC www.tombarefoot.com [Source type: General]

[10][11] 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.^ Keep in mind however that you won't be seeing anything different than you would in the A-Star but perhaps in a bit more deluxe manner.
  • Maui Helicopter Tour in Maui Hawaii Helicopters Tours Rides 7 January 2010 13:56 UTC www.tombarefoot.com [Source type: General]

^ This is a much closer look than you would get in a commercial airliner, but it isn't all that close.

^ My fixed wing experience allowed me to concentrate more on actually flying the aircraft as opposed to trying to take in instruments, radio etc.

In July 1754, Mikhail Lomonosov demonstrated a small coaxial 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's 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.[10] 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.[12]
.In 1861, the word "helicopter" was coined by Gustave de Ponton d'Amécourt, a French inventor who demonstrated a small, steam-powered model.^ Big jet-powered helicopters are safer than small airplanes, but not by the huge factor that big jet-powered airplanes are safer.

.While celebrated as an innovative use of a new metal, aluminum, the model never lifted off the ground.^ I’ve tried Testor’s plastic model glue, but after one or two runs, the glue just “lifts off” the blades.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

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. .Enrico Forlanini's unmanned helicopter was also powered by a steam engine.^ In a turbine-powered helicopter like a Bell 206 JetRangers the blades are heavy and the blades won't slow down for several seconds after an engine failure.

.It was the first of its type that rose to a height of 13 meters (43 ft), where it remained for some 20 seconds after a vertical take-off from a park in Milan, in 1877. Emmanuel Dieuaide's steam-powered design featured counter-rotating rotors powered through a hose from a boiler on the ground.^ If the pilot takes his hands off the controls, the plane will fly itself for 30 seconds (or 3 hours if typically equipped with an autopilot).

Dandrieux's design had counter-rotating rotors and a 7.7-pound (3.5-kilogram) steam engine. It rose more than 40 feet (12 m) and flew for 20 seconds circa 1878.[10]
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.[13] .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).^ An R22 loses power at higher altitudes because its engine is not turbocharged.

^ In a turbine-powered helicopter like a Bell 206 JetRangers the blades are heavy and the blades won't slow down for several seconds after an engine failure.

^ Piston-powered helicopters, which these days means "Robinson", suffer 13-20 accidents per year, with roughly 2 of those accidents being fatal.

[14] .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.^ I my Micro Mosquito in early June 2007 and I must say that it is THE best multi rotor helicopter I have ever owned!.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

[15]

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.^ Within a minute of starting up, I had control of one control, gradually moving up to all controls within about another minute or so!

^ The two professional pilots up front and the superbly capable equipment make flying an airplane seem easy.

^ Before you get into the air you'll probably spend about half an hour on a preflight inspection of the helicopter.

[3] 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.
Hungarian "PKZ" military helicopter (Ganz Company 1916)
.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.^ Schweizer, for example, which bought the old Hughes design, manufactures a comparative handful of piston-engine helicopters each year.

^ The same person has very likely only been on one or two helicopter rides in his life.

^ The net result of using an aerodiesel engine could be a helicopter with longer range and much better performance in the mountains.

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.^ At no time did he lose control of the machine, even hover taxiing back to the parking spot.

1, it was reported to be the first truly free flight with a pilot.[n .1] 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.^ Request Information: Take the next step in your helicopter training by contacting our featured helicopter flight schools for more info.
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

^ Complete Helicopters is proud to offer top quality helicopter flight school instruction at reasonable prices.
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

^ Helicopters are unstable and very few are equipped with autopilots.

[3]
During the World War I in 1917, the engineers of Hungarian Ganz Company designed a radical motorized flying machine to replace the dangerous hydrogen-filled balloons then being used to observe enemy positions. The P.K.Z. aircraft flew to a height of over 50 m. It was supported by 120 hp engines and two massive wooden propellers turning in opposite directions. It was intended to lift a pilot, observer, machine gun and fuel for an hour's flight.[16] .Because of great success and curious design, many specialists consider it as the world's first real helicopter.^ Utah Helicopter - Montana You can follow many exciting and lucrative paths in the world of rotor-wing aviation.
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

^ Utah Helicopter - Salt Lake City, Utah You can follow many exciting and lucrative paths in the world of rotor-wing aviation.
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

^ Utah Helicopter - Wyoming You can follow many exciting and lucrative paths in the world of rotor-wing aviation.
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

[17]

Early development

In the early 1920s, Argentine Raúl Pateras Pescara, while working in Europe, demonstrated one of the first successful applications of cyclic pitch.[3] .Coaxial, contra-rotating, biplane rotors could be warped to cyclically increase and decrease the lift they produced.^ I discovered that I could deliver more forward power to the tail rotor and increase motor speed from inside the transmitter.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

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.^ As long as the helicopter could autorotate to a tennis court, road, or field in the event of an engine failure, the pilot can fly much lower than in an airplane.

^ (In practice the cyclic flare is more important than the "hovering autorotation" at the end; a lot of people walk away from helicopter engine failures if they get the cyclic flare right but can't manage to pull the collective smoothly at the last moment.

^ In a turbine-powered helicopter like a Bell 206 JetRangers the blades are heavy and the blades won't slow down for several seconds after an engine failure.

By January 1924, Pescara's helicopter No. .3 could fly for up ten minutes.^ Or we load up four people and full fuel and fly to a Manhattan heliport in 1 hour 45 minutes from Boston.

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).^ Learning to fly helicopters is one of life’s most rewarding adventures!
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

^ Blaine, Minnesota Our Private Pilot Training Program is your first step in enjoying all the excitement and privileges of helicopter flying.
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

^ If you are training at a school with only one helicopter and one instructor, the risk of being unable to fly is very high.

.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).^ I taught a U.S. Navy airplane pilot to fly and hover a helicopter in about twenty minutes.

[18] 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).[18] Oehmichen also set the 1 km closed-circuit record at 7 minutes 40 seconds.[3]
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.[19] Cierva had discovered aerodynamic and structural deficiencies in his early designs that could cause his autogyros to flip over after takeoff.^ At C-R Helicopters, custom designed, FAA approved courses take you from entry level to the most advanced qualification possible.
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

^ Helicopter Tours and Rides in Maui - Without a doubt the single most spectacular activity you can take on Maui would be a helicopter flight.
  • Maui Helicopter Tour in Maui Hawaii Helicopters Tours Rides 7 January 2010 13:56 UTC www.tombarefoot.com [Source type: General]

^ Baker Aircraft - Baker City, Oregon Baker Aircraft is offering a helicopter flight school with an accelerated 2 week private pilot training program in our rotor wing aircraft.
  • Helicopter Training and Helicopter Flight Schools Directory - Helicopter-Training.net 7 January 2010 13:56 UTC www.helicopter-training.net [Source type: General]

.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 three-channel digital remote controls up & down motion, forward & reverse, turning left & right and even allows the Mosquito to hover.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

A crash in 1927, led to the development of a drag hinge to relieve further stress on the rotor from its flapping motion.[19] .These two developments allowed for a stable rotor system, not only in a hover, but in forward flight.^ A three-channel digital remote controls up & down motion, forward & reverse, turning left & right and even allows the Mosquito to hover.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

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.^ Then you take the collective while the instructor controls the cyclic and pedals.

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 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,[20] a concept that was later adopted by other helicopter designers, including Bleeker and Kaman.^ I am going to try taking mine back – despite using the trim control and following the troubleshooting directions, bending every rotor blade, the helicopter will not stop spinning right.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

^ It has more controllability then any other mini RC helicopter I’ve ever flown.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

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).[20]
.At this same time, in the Soviet Union, the aeronautical engineers Boris N. Yuriev and Alexei M. Cheremukhin, working at TsAGI, constructed and flew the TsAGI 1-EA single rotor helicopter, which used an open tubing framework, a four blade main rotor, and twin sets (one set of two each at the nose and tail) of 1.8 meters (6 ft) diameter anti-torque rotors.^ The tail rotor is counterbalancing engine torque but at the same time is pushing the machine to the right.

^ Work on using the pedals and cyclic so that the helicopter is neither yawing nor drifting when it hits the pavement.

^ The third tweak was increasing the tail rotor surface by sticking a few layers of scotch tape to the blades, and cutting them into a nice symmetrical ‘rotor’ shape.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

Powered by two M-2 powerplants, themselves up-rated Soviet copies of the Gnome Monosoupape rotary radial engine of World War I, the TsAGI 1-EA made several successful low altitude flights, and 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.[21][22]
.Nicolas Florine, a Russian engineer, built the first twin tandem rotor machine to perform a free flight.^ The tail rotor is counterbalancing engine torque but at the same time is pushing the machine to the right.

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.^ A co-worker thought it would be funny and shot the skeeter out of the air with a spring metal paper holder and tore one of the rotors.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

.Therefore the rotors had to be tilted slightly in opposite directions to counter torque.^ The main rotor hinges are so flexible that they will counter any attempt at tilting them.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

Using hingeless rotors and co-rotation also minimised the stress on the hull. At the time, it was probably the most stable helicopter in existence.[23][24]
.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.^ Nonetheless, pilots of small aircraft managed to crash roughly 7 times in every 100,000 hours; 1.4 out of those 7 times, the accident was fatal.

^ I used some clear packing tape (the scotch tape I used at first was too flimsy and wouldn’t last) and repaired it and it works perfect – no difference in flight controls .
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

^ Experience with a particular aircraft or "time in type" is a huge contributor to safety; nothing stops a pilot from bringing an instructor along for the first 100 hours in a new aircraft.

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).^ One of my long-ago instructors neglected to perform a proper pre-flight inspection and plowed in, taking the mechanic with him.

^ One second after that the helicopter has responded to two seconds of continuous pressure by rushing backwards at a frightening clip.

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.^ Flight schools, however, were quick to notice that the R22 was the world's cheapest helicopter to operate and began snapping them up.

^ Going from airport to airport in a well-maintained helicopter is not actually all that challenging or risky, but to the general public it is miraculous that such a flight is ever completed.

In February 1938, Hanna Reitsch became the first female helicopter pilot, exhibiting the Fw 61 before crowds in the Deutschlandhalle.
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 Sea, while the Focke Achgelis Fa 223 Drache was used in Europe. 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.^ If Schweizer were to cease producing and supporting civilian helicopters it would probably result in a revenue boost for Sikorsky because the people and workshops could be transferred to military contracts.

Prior to the war, LePage had received the patent rights to develop helicopters patterned after the Fw 61, and built the XR-1.[25] 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.^ Experience with a particular aircraft or "time in type" is a huge contributor to safety; nothing stops a pilot from bringing an instructor along for the first 100 hours in a new 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.^ If you are training at a school with only one helicopter and one instructor, the risk of being unable to fly is very high.

^ If, on the other hand, you get your helicopter instrument rating at 249 hours and your CFII-H at 250 hours, you only need to get sharp once.

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.[26]
.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.^ Finally you raise the collective as the helicopter falls, using the stored energy in the blades against the force of gravity.

^ I believe the main problem with the design is that the helicopter is too damn good at stabilizing itself.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

^ I am going to try taking mine back – despite using the trim control and following the troubleshooting directions, bending every rotor blade, the helicopter will not stop spinning right.
  • Micro Mosquito helicopter takes to the tiny skies - SlashGear 7 January 2010 13:56 UTC www.slashgear.com [Source type: FILTERED WITH BAYES]

The subsequent Model 30 helicopter demonstrated the simplicity and ease of the design. 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 become the most popular helicopter model for nearly 30 years.^ In a turbine-powered helicopter like a Bell 206 JetRangers the blades are heavy and the blades won't slow down for several seconds after an engine failure.

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.[27]
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.[28] These operations are referred to as longline because of the long, single sling line used to carry the load.[29]
Helitack is the use of helicopters to combat wildland fires.[30] 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. Companies such as CHC Helicopter, Bristow Helicopters, and Air Logistics specialize in this type of operation.
Other uses of helicopters include, but are not limited to:

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.[31]
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 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 lager 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, such as Rotomotion's SR20 use electric motors.[32] 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[33].

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. Although, 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 at a specific RPM. The throttle controls the power produced by the engine, which is connected to the rotor by a 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.
  • 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.

Safety

Limitations

HAL Dhruv performing aerobatics during the Royal International Air Tattoo in 2008.
RAN Squirrel helicopters during a display at the 2008 Melbourne Grand Prix
.The main limitation of the helicopter is its low speed.^ Helicopters are particularly suited to searching for lost people due to their slow hovering speed and ability to fly low to the ground.
  • RACQ Capricorn Helicopter Rescue 7 January 2010 13:56 UTC www.chrs.org.au [Source type: News]

^ The question was "What are three limitations to forward speed in helicopter flight" and the answer "The blades fall off!"
  • Chinook Helicopters - Helicopter Pilot Training 7 January 2010 13:56 UTC chinookhelicopters.com [Source type: General]

^ Conventional helicopters are incredibly useful vehicles in many short-range scenarios - but their asymmetrical aerodynamics enforce a fairly low terminal speed limit of around 150mph, making them less than ideal for longer-range missions.
  • Helicopters - Gizmag Tag 7 January 2010 13:56 UTC www.gizmag.com [Source type: General]

There are several reasons why a helicopter cannot fly as fast as a fixed wing aircraft. When the helicopter is hovering, the outer tips of the rotor travel at a speed determined by the length of the blade and the RPM. In a moving helicopter, however, the speed of the blades relative to the air depends on the speed of the helicopter as well as on their rotational velocity. The airspeed of the advancing rotor blade is much higher than that of the helicopter itself. It is possible for this blade to exceed the speed of sound, and thus produce vastly increased drag and vibration. See Wave drag.
Because the advancing blade has higher airspeed than the retreating blade and generates a dissymmetry of lift, rotor blades are designed to "flap" – lift and twist in such a way that the advancing blade flaps up and develops a smaller angle of attack. Conversely, the retreating blade flaps down, develops a higher angle of attack, and generates more lift. At high speeds, the force on the rotors is such that they "flap" excessively and the retreating blade can reach too high an angle and stall. For this reason, the maximum safe forward airspeed of a helicopter is given a design rating called VNE, Velocity, Never Exceed.[34] In addition, at extremely high speeds, it is possible for the helicopter to travel faster than the retreating blade which would inevitably stall the blade, regardless of the angle of attack.
During the closing years of the 20th century designers began working on helicopter noise reduction. Urban communities have often expressed great dislike of noisy aircraft, and police and passenger helicopters can be unpopular. The redesigns followed the closure of some city heliports and government action to constrain flight paths in national parks and other places of natural beauty.
Helicopters also vibrate; an unadjusted helicopter can easily vibrate so much that it will shake itself apart. To reduce vibration, all helicopters have rotor adjustments for height and weight. Blade height is adjusted by changing the pitch of the blade. Weight is adjusted by adding or removing weights on the rotor head and/or at the blade end caps. Most also have vibration dampers for height and pitch. Some also use mechanical feedback systems to sense and counter vibration. Usually the feedback system uses a mass as a "stable reference" and a linkage from the mass operates a flap to adjust the rotor's angle of attack to counter the vibration. Adjustment is difficult in part because measurement of the vibration is hard, usually requiring sophisticated accelerometers mounted throughout the airframe and gearboxes. The most common blade vibration adjustment measurement system is to use a stroboscopic flash lamp, and observe painted markings or coloured reflectors on the underside of the rotor blades. The traditional low-tech system is to mount coloured chalk on the rotor tips, and see how they mark a linen sheet. Gearbox vibration most often requires a gearbox overhaul or replacement. Gearbox or drive train vibrations can be extremely harmful to a pilot. The most severe being pain, numbness, loss of tactile discrimination and dexterity.

Hazards

As with any moving vehicle, unsafe operation could result in loss of control, structural damage, or fatality. The following is a list of some of the potential hazards for helicopters:
  • Settling with power, also known as a vortex ring state, is when the aircraft is unable to arrest its descent due to the rotor's downwash interfering with the aerodynamics of the rotor.
  • Retreating blade stall is experienced during high speed flight and is the most common limiting factor of a helicopter's forward speed.
  • Ground resonance affects helicopters with fully articulated rotor systems having a natural lead-lag frequency less than the blade rotation frequency.
  • Low-G condition affects helicopters with two-bladed main rotors, particularly lightweight helicopters.
  • Dynamic rollover in which the helicopter pivots around one of the skids and 'pulls' itself onto its side.
  • Powertrain failures, especially those that occur within the shaded area of the height-velocity diagram.
  • Tail rotor failures which occur from either a mechanical malfunction of the tail rotor control system or a loss of tail rotor thrust authority, called Loss of Tail-rotor Effectiveness (LTE).
  • Brownout in dusty conditions or whiteout in snowy conditions.
  • Low Rotor RPM, or rotor droop, in which the engine cannot drive the blades at sufficient RPM to maintain flight.
  • Wire and tree strikes due to low altitude operations and take-offs and landings in remote locations.[35]

Deadliest crashes

  1. 2002 Khankala Mi-26 crash: Mi-26 shot down over Chechnya in 2002; 127 killed.
  2. 1997 Israeli helicopter disaster: MH-53 crash in Israel in 1997; 73 killed.
  3. 1977 Israeli CH-53 crash: CH-53 crash near Yitav in the Jordan Valley on 10 May 1977; 54 killed.
  4. September 11, 1982, at an airshow in Mannheim, Germany a United States Army Chinook (serial number 74-22292) crashed killing 46.[36][37]
  5. 1986 British International Helicopters Chinook crash: a British International Helicopters Boeing 234LR Chinook crashed in the Shetland Islands; 45 killed.
  6. 2009 Pakistan Army Mil Mi-17 crash: 41 killed.
  7. 26 January 2005: a CH-53E Super Stallion from HMH-361 crashed near Ar Rutbah, Iraq killing all 31 service members onboard.[38]

See also

References

Notes
  1. ^ Dr. J. Gordon Leishman, a Technical Fellow of AHS International, presented a paper at the 64th Annual Forum of the American Helicopter Society International, on the aerodynamic capability of Cornu's design, arguing that the aircraft lacked the power and rotor loading to lift free of the ground in manned flight.
Footnotes
  1. ^ "helicopter". Online Etymology Dictionary. Retrieved: 28 November 2007
  2. ^ Cottez 1980, p. 181.
  3. ^ a b c d e Munson 1968
  4. ^ Hirschberg, Michael J. and David K. Dailey, "Sikorsky." US and Russian Helicopter Development In the 20th Century. American Helicopter Society, International. 7 July 2000.
  5. ^ Leishman, J. Gordon. Principles of Helicopter Aerodynamics. Cambridge aerospace series, 18. Cambridge: Cambridge University Press, 2006. ISBN 9780521858601
  6. ^ "Early Helicopter History". Aerospaceweb.org. Accessed on 1 November 2008.
  7. ^ Goebel, Greg. "The Invention Of The Helicopter". Vectorsite.net. Retrieved: 11 November 2008.
  8. ^ Fay, John. "Helicopter Pioneers - Evolution of Rotary Wing Aircraft". Helicopter History Site. Retrieved: 28 November 2007.
  9. ^ English, Dave, ed. "Predictions", Great Aviation Quotes. Skygod.com. Retrieved: 9 December 2007.
  10. ^ a b c Rumerman, Judy. "Early Helicopter Technology". Centennial of Flight Commission. Accessed on 9 December 2007.
  11. ^ Pilotfriend.com "Leonardo Da Vinci's Helical Air Screw". Pilotfriend.com. Accessed on 28 November 2007.
  12. ^ Hallion, Richard P. "Pioneers of Flight: Alphonse Pénaud". Air Force Link. Accessed on 1 November 2008.
  13. ^ Bryan, George S. Edison: the Man and His Work. Garden City, New York: Garden City Publ., 1926. p. 249.
  14. ^ "Pioneers - 1900/1930". Helicopter History Site. Retrieved: 3 May 2007.
  15. ^ Dowd, George L. "Flops of famous inventors". Popular Science. December 1930.
  16. ^ http://www.aviastar.org/helicopters_eng/petroczy.php
  17. ^ http://www.aviapress.com/viewonekit.htm?ROD-008
  18. ^ a b Rumerman, Judy. "Helicopter Development in the Early Twentieth Century". Centennial of Flight Commission. Retrieved: 28 November 2007.
  19. ^ a b "The Contributions of the Autogyro". Centennial of Flight Commission. Retrieved: 28 November 2007.
  20. ^ a b Spenser 1998
  21. ^ [1]
  22. ^ [2]
  23. ^ [3], Aviastar. Retrieved: 26 June 2008
  24. ^ Watkinson 2004, p. 358.
  25. ^ Francillon 1997
  26. ^ Day, Dwayne A. "Igor Sikorsky - VS 300". Centennial of Flight Commission. Retrieved: 9 December 2007.
  27. ^ Connor, R.D. and R.E. Lee. "Kaman K-225". Smithsonian National Air and Space Museum. 27 July 2001. Retrieved: 9 December 2007.
  28. ^ Day, Dwayne A. "Skycranes". Centennial of Flight Commission. Accessed on 1 October 2008.
  29. ^ Webster, L. F. The Wiley Dictionary of Civil Engineering and Construction. New York: Wiley, 1997. ISBN 0-47118-115-3
  30. ^ Butler, Bret W., Roberta A. Bartlette, Larry S. Bradshaw, Jack D. Cohen, Patricia L. Andrews, Ted Putnam, and Richard J. Mangan. "Appendix A:Glossary". Fire Behavior Associated with the 1994 South Canyon Fire on Storm King Mountain, Colorado. research paper. U.S. Dept. of Agriculture, Forest Service. September 1998. Accessed on 2 November 2008.
  31. ^ Frawley 2003, p. 151.
  32. ^ Rotomotion SR20 fact sheet, Rotomotion.
  33. ^ Jay Leno's EcoJet Concept
  34. ^ Rotorcraft Flying Handbook. Washington: Skyhorse Publishing, Inc.. 2007. pp. 3–7. ISBN 1-60239-060-6.  
  35. ^ Helicopter Accidents in Hawaii
  36. ^ Chinook crash in Mannheim
  37. ^ Crash Death, 3rd in 8 Years, Not Expected to Halt Future Shows
  38. ^ "Incident Date 050126 HMH-361 CH-53D - BuNo unknown - incident not yet classified - near Ar Rutbah, Iraq". Marine Corps Combat Helicopter Association. http://www.popasmoke.com/kia/incidents.php?incident_id=278&conflict_id=32. Retrieved 2007-11-20.  
Bibliography
  • Chiles, James R. The God Machine: From Boomerangs to Black Hawks: The Story of the Helicopter. New York: Bantam Books, 2007. ISBN 0553804472.
  • Cottez, Henri. Dictionnaire des structures du vocabulaire savant. Paris: Les Usuels du Robert. 1980. ISBN 0-851-77827-5.
  • Flight Standards Service. Rotorcraft Flying Handbook: FAA Manual H-8083-21. Washington, DC: Federal Aviation Administration, U.S. Dept. of Transportation, 2001. ISBN 1-56027-404-2.
  • Francillon, René J. McDonnell Douglas Aircraft since 1920: Volume II. London: Putnam, 1997. ISBN 0-851-77827-5.
  • Frawley, Gerard. The International Directory of Civil Aircraft, 2003-2004. Fyshwick, Canberra, Act, Australia: Aerospace Publications Pty Ltd., 2003, p. 155. ISBN 1-875671-58-7.
  • Munson, Kenneth. Helicopters and other Rotorcraft since 1907. London: Blandford Publishing, 1968. ISBN 978-0-713-70493-8.
  • Thicknesse, P. Military Rotorcraft (Brassey's World Military Technology series). London: Brassey's, 2000. ISBN 1-857533-25-9.
  • Watkinson, John. Art of the Helicopter. Oxford: Elsevier Butterworth-Heinemann, 2004. ISBN 0750657154
  • Wragg, David W. Helicopters at War: A Pictorial History. London: R. Hale, 1983. ISBN 0-709-00858-9.

External links


Simple English

File:Flight.rob.arp.
A Robinson R22 Alpha helicopter flying just a little above the ground

A helicopter is a kind of flying machine or aircraft. A helicopter lifts up off of the ground and moves because of its rotors. A rotor is several small wings, called rotor blades, that spin together around a shaft. For that reason, helicopters are sometimes called rotary-wing aircraft. A helicopter flies differently from an airplane. An airplane must move forward to stay in the air, but because the helicopter's rotor blades are always moving, the helicopter can stop and stay in one place above the ground. This allows them to land in places where an airplane cannot. Helicopters can move by tilting their rotors, which causes the rotor blades to fly in the direction the rotor is tilted.

History

Since around 400 BC, the Chinese had a flying top that was used as a children's toy. The flying top was made from bamboo and used the same method of spinning wings to fly up in the air. Later flying tops were made of feathers tied to a stick. Leonardo da Vinci first thought of a helicopter flown by a man in 1490, and drew pictures of his ideas. It was hundreds of years later (in the early 20th century) before anyone built one that could really fly. The first man to fly a helicopter was a Frenchman, Paul Cornu. Then a Russian immigrant to America, Igor Sikorsky, built and perfected the first practical helicopter.

Uses

Helicopters are especially useful when there are floods and other disasters. Food packets, water, medicines and clothes are dropped from the air to people on the ground who cannot be reached by road. When people are injured, helicopters can carry them to hospitals faster than an ambulance on the road. Helicopters are also used by the military, because they can move troops and equipment to places an airplane cannot take them. Guns can be mounted on them, and missiles can be shot from them.

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