Jennifer Murray (née Mather ; born June 1940 in Providence, Rhode Island ) is a pilot. In 2000 she circumnavigated the globe in a Robinson R44 helicopter, travelling 36,000 miles (58,000 km) in 97 days, earning her the Guinness World Record for the first helicopter circumnavigation by a woman.
79-618: The Robinson R44 is a four-seat light helicopter produced by Robinson Helicopter Company since 1992. Derived from the company's two-seat Robinson R22 , the R44 features hydraulically assisted flight controls and a larger engine. It was first flown on 31 March 1990 and received FAA certification in December 1992, with the first delivery in February 1993. The R44 has been the world's best-selling general aviation (GA) helicopter every year since 1999. It
158-610: A runway . In 1942, the Sikorsky R-4 became the first helicopter to reach full-scale production . Although most earlier designs used more than one main rotor, the configuration of a single main rotor accompanied by a vertical anti-torque tail rotor (i.e. unicopter , not to be confused with the single-blade monocopter ) has become the most common helicopter configuration. However, twin-rotor helicopters (bicopters), in either tandem or transverse rotors configurations, are sometimes in use due to their greater payload capacity than
237-444: A collective input is made, all the blades change equally, and the result is the helicopter increasing or decreasing in altitude. A swashplate controls the collective and cyclic pitch of the main blades. The swashplate moves up and down, along the main shaft, to change the pitch of both blades. This causes the helicopter to push air downward or upward, depending on the angle of attack . The swashplate can also change its angle to move
316-417: 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 . Due to the operating characteristics of the helicopter—its ability to take off and land vertically, and to hover for extended periods of time, as well as
395-638: A few more flights and achieved a height of nearly 2.0 metres (6.5 ft), but it proved to be unstable and was abandoned. Jennifer Murray Jennifer Mather was born in Providence, Rhode Island , in June 1940. She was educated at Downe House School in Berkshire , UK. Her paternal grandfather was Sir William Mather , the British industrialist who was chairman of Mather & Platt . In August 1997, Murray became
474-459: 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
553-405: 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
632-504: A helicopter powered by a gasoline engine with box kites attached to a mast by cables for a rotor, but it never flew. In 1906, two French brothers, Jacques and Louis Breguet , began experimenting with airfoils for helicopters. In 1907, those experiments resulted in the Gyroplane No.1 , possibly as the earliest known example of a quadcopter. Although there is some uncertainty about the date, sometime between 14 August and 29 September 1907,
711-416: 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 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
790-421: A modified pallet jack. The other option for ground handling is a landing platform which is large enough for the helicopter to safely land on, has wheels underneath and can be towed between the hangar and take-off location. These are heavy and must be towed with a vehicle. Platforms are commonly used with R44s. In 1997, a Robinson R44 was piloted by Jennifer Murray for the first helicopter circumnavigation of
869-642: A post-accident fuel leak." The company recommended that the change should be done as soon as practical, but no later than 31 December 2014. The compliance date was later moved to 30 April 2013. An accident investigation by the Australian Transport Safety Bureau (ATSB) in March 2013 found, after analyzing historical data, that a significantly higher proportion of R44 aircraft (12%) caught fire after crashing, compared to accidents involving other types of piston-engine helicopters (7%). Preliminary analysis by
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#1732858136346948-470: A process of rebracketing , the word is often (erroneously, from an etymological point of view) perceived by English speakers as consisting of heli- and -copter , leading to words like helipad and quadcopter . English language nicknames for "helicopter" include "chopper", "copter", "heli", and "whirlybird". In the United States military, the common slang is "helo" pronounced /ˈhiː.loʊ/. A helicopter
1027-489: A rotor. The spinning creates lift, and the toy flies when released. The 4th-century AD Daoist book Baopuzi by Ge Hong ( 抱朴子 "Master who Embraces Simplicity") reportedly describes some of the ideas inherent to rotary wing aircraft. Designs similar to the Chinese helicopter toy appeared in some Renaissance paintings and other works. In the 18th and early 19th centuries Western scientists developed flying machines based on
1106-441: A single main rotor, but torque created by its aerodynamic drag must be countered by an opposed torque. The design that Igor Sikorsky settled on for his VS-300 was a smaller tail rotor. The tail rotor pushes or pulls against the tail to counter the torque effect, and this has become the most common configuration for helicopter design, usually at the end of a tail boom . Some helicopters use other anti-torque controls instead of
1185-417: A state called translational lift which provides extra lift without increasing power. This state, most typically, occurs when the airspeed reaches approximately 16–24 knots (30–44 km/h; 18–28 mph), and may be necessary for a helicopter to obtain flight. In forward flight a helicopter's flight controls behave more like those of a fixed-wing aircraft. Applying forward pressure on the cyclic will cause
1264-429: Is a cylindrical metal shaft that extends upwards from the transmission. At the top of the mast is the attachment point for the rotor blades called the hub. Main rotor systems are classified according to how the rotor blades are attached and move relative to the hub. There are three basic types: hingeless, fully articulated, and teetering; although some modern rotor systems use a combination of these. Most helicopters have
1343-460: Is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors . This allows the helicopter to take off and land vertically , to hover , and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of short take-off and landing ( STOL ) or short take-off and vertical landing ( STOVL ) aircraft cannot perform without
1422-452: Is a type of rotorcraft in which lift and thrust are supplied by one or more horizontally-spinning rotors. By contrast the autogyro (or gyroplane) and gyrodyne have a free-spinning rotor for all or part of the flight envelope, relying on a separate thrust system to propel the craft forwards, so that the airflow sets the rotor spinning to provide lift. The compound helicopter also has a separate thrust system, but continues to supply power to
1501-452: 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
1580-535: Is equipped to stabilize and provide limited medical treatment to a patient while in flight. The use of helicopters as air ambulances is often referred to as " MEDEVAC ", and patients are referred to as being "airlifted", or "medevaced". This use was pioneered in the Korean War , when time to reach a medical facility was reduced to three hours from the eight hours needed in World War II , and further reduced to two hours by
1659-399: Is one of the most-produced GA aircraft of the 21st century, with 5,941 deliveries from 2001 to 2020. The R44 is a single-engined helicopter with a semi-rigid two-bladed main rotor, a two-bladed tail rotor and a skid landing gear. It has an enclosed cabin with two rows of side-by-side seating for a pilot and three passengers. Tail rotor direction of rotation on the R44 is reversed compared to
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#17328581363461738-665: 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 or motorcycle engines. 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. There are also human-powered helicopters . A helicopter has four flight control inputs. These are
1817-411: 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. As a helicopter moves from hover to forward flight it enters
1896-558: 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, or cannot transport the patient to a medical facility in time. Helicopters are also used when patients need to be transported between medical facilities and air transportation is the most practical method. An air ambulance helicopter
1975-572: The Bell 206 with 3,400. Most were in North America with 34.3% then in Europe with 28.0% followed by Asia-Pacific with 18.6%, Latin America with 11.6%, Africa with 5.3% and Middle East with 1.7%. The earliest references for vertical flight came from China. Since around 400 BC, Chinese children have played with bamboo flying toys (or Chinese top). This bamboo-copter is spun by rolling a stick attached to
2054-517: The Cornu helicopter which used two 6.1-metre (20 ft) counter-rotating rotors driven by a 24 hp (18 kW) Antoinette engine. On 13 November 1907, it lifted its inventor to 0.3 metres (1 ft) 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 completed
2133-683: The New Zealand Civil Aviation Authority issued an Airworthiness Directive grounding 80 of the country's R44 helicopters after two people were killed in an accident traced to a particular type of main rotor blade, the P/N C016-7 or Dash 7, which a preliminary investigation determined had failed in flight. It was the second failure or partial failure in two months. This was the largest-scale grounding of any aircraft in New Zealand's history. The CAA determined through laboratory tests that
2212-493: The Vietnam War . In naval service a prime function of rescue helicopters is to promptly retrieve downed aircrew involved in crashes occurring upon launch or recovery aboard aircraft carriers. In past years this function was performed by destroyers escorting the carrier, but since then helicopters have proved vastly more effective. Police departments and other law enforcement agencies use helicopters to pursue suspects and patrol
2291-538: The ATSB of the NTSB's accident database found a similar statistic, with 15% of accidents in the US involving R44 helicopters having post-crash fires. Although the data did not consider which type of fuel tanks were fitted, the report mentioned four fatal accidents to the R44 fitted with bladder-type tanks, but as far as they knew, did not involve a post-accident fire. The ATSB recommended that
2370-546: The Australian Civil Aviation Safety Authority (CASA) take further action to urge R44 owners to fit bladder-type tanks. The FAA , the governing body in the country of manufacture whose directives would normally be followed in other countries like Australia, had not mandated the retrofit; CASA therefore issued Australian-specific airworthiness directive AD/R44/23, grounding R44 aircraft on 30 April 2013 that had not yet been upgraded. On 19 February 2015,
2449-554: 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
Robinson R44 - Misplaced Pages Continue
2528-755: The Chinese top in a model consisting of contrarotating 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, developed a model of feathers, similar to that of 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
2607-478: The Chinese toy. It was not until the early 1480s, when Italian polymath 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 craft rotate. As scientific knowledge increased and became more accepted, people continued to pursue
2686-453: The Gyroplane No. 1 lifted its pilot into the air about 0.6 metres (2 ft) for a minute. 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
2765-566: The Martian atmosphere is 100 times thinner than Earth's, its two blades spin at close to 3,000 revolutions a minute, approximately 10 times faster than that of a terrestrial helicopter. In 2017, 926 civil helicopters were shipped for $ 3.68 billion, led by Airbus Helicopters with $ 1.87 billion for 369 rotorcraft, Leonardo Helicopters with $ 806 million for 102 (first three-quarters only), Bell Helicopter with $ 696 million for 132, then Robinson Helicopter with $ 161 million for 305. By October 2018,
2844-514: The R22 for improved yaw control authority. On the R44 the advancing blade is on the bottom. Designed during the 1980s by Frank Robinson and his staff of engineers, the R44 first flew on 31 March 1990. The R44 Astro was awarded an FAA Type Certificate in December 1992 , with the first deliveries taking place in January 1993. The first R44 Newscopter featuring onboard electronic news gathering equipment
2923-549: The USA before we review the Airworthiness notice." Following the grounding in New Zealand, Australia's Civil Aviation Safety Authority (CASA) also grounded R44 helicopters with the same rotor blades. On 6 February 2024 an R44 helicopter crashed into Ranco Lake near Lago Ranco , Los Ríos Region (English: Rivers Region), Chile . 3 of the 4 occupants survived, with the fatal victim being the ex-President of Chile Sebastián Piñera who
3002-550: The aircraft's handling properties under low airspeed conditions—it has proved advantageous 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 of people and cargo, military uses, construction, firefighting, search and rescue , tourism , medical transport, law enforcement, agriculture, news and media , and aerial observation , among others. A helicopter used to carry loads connected to long cables or slings
3081-410: The aviation industry; and the turboshaft engine for helicopter use, pioneered in December 1951 by the aforementioned Kaman K-225, finally gave helicopters an engine with a large amount of power and a low weight penalty. Turboshafts are also more reliable than piston engines, especially when producing the sustained high levels of power required by a helicopter. The turboshaft engine was able to be scaled to
3160-404: The ball then pushes down on the handle to lift the nose. Others provide a repurposed car-style hydraulic jack or an electric jack to lift the nose. Tow carts are available with no motive power, a gas engine or one or two electric motors operated from one or two batteries. Some of the non-powered tow carts are set up to be towed such as behind a golf cart or quad cycle. One manufacturer offered
3239-435: The blades angle forwards or backwards, or left and right, to make the helicopter move in those directions. 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
Robinson R44 - Misplaced Pages Continue
3318-677: The building of roads. These operations are referred to as longline because of the long, single sling line used to carry the load. In military service helicopters are often useful for delivery of outsized slung loads that would not fit inside ordinary cargo aircraft: artillery pieces, large machinery (field radars, communications gear, electrical generators), or pallets of bulk cargo. In military operations these payloads are often delivered to remote locations made inaccessible by mountainous or riverine terrain, or naval vessels at sea. In electronic news gathering , helicopters have provided aerial views of some major news stories, and have been doing so, from
3397-406: The cockpit from overhead. The control is called the cyclic because it changes cyclic pitch of the main blades. 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,
3476-464: 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
3555-528: The early 21st century, as well as recently weaponized utilities such as artillery spotting , aerial bombing and suicide attacks . The English word helicopter is adapted from the French word hélicoptère , coined by Gustave Ponton d'Amécourt in 1861, which originates from the Greek helix ( ἕλιξ ), genitive helikos (ἕλῐκος), "helix, spiral, whirl, convolution" and pteron ( πτερόν ) "wing". In
3634-403: The engine. R44s with fixed floats or deployed pop-out emergency floats must have wheels installed under the skids as the bracket is not accessible. All models and years of the R44 include a 3 ⁄ 4 -inch-diameter tow ball mounted on the bottom of the fuselage, near the front and offset slightly to the left. A tow cart or tug can be engaged with the ball and then used to lift the front of
3713-439: The event was taken by Max Skladanowsky , but it remains lost . In 1885, Thomas Edison was given US$ 1,000 (equivalent to $ 34,000 today) 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
3792-486: 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
3871-620: The first woman to fly a helicopter around the world when she co-piloted her Robinson R44 with Quentin Smith on the eastward circumnavigation. The 97-day flight was also an eastbound speed record for a piston-powered helicopter. The flight departed from Denham, Buckinghamshire , UK on 10 May 1997, and her stopover at Oakland Airport in California on 20 July is commemorated at the Oakland Aviation Museum . On 6 September 2000, Murray became
3950-583: The first woman to make a solo flight around the world in a helicopter and the first person to do so without autopilot . In 2007, Murray and co-pilot Colin Bodill became the first to land a helicopter on both North and South Poles, their second attempt. Their first, in 2003, ended in a near-fatal crash in Antarctica, after Murray had just become the first woman to fly a helicopter to the South Pole. At 71, Jennifer
4029-407: The front of the skids on the ground. The helicopter can be moved by pulling down on the tail to lift the front of the skids off the ground. Because of the size and weight of the R44 and the height of the tail from the ground, as compared to the R22, it is extremely difficult if not impossible for a single person to move the helicopter this way. Another person can help by pushing on the bracing behind
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#17328581363464108-406: The helicopter to clear the skids from the ground after the wheels are installed and rotated to lift the rear of the skids. This makes it possible for a single person to move the helicopter, even over significant distances or not-level surfaces. Tow carts are available with a variety of features. There exist manual versions which place the ball mating device behind the wheels so the operator engages
4187-404: The high operating cost of helicopters cost-effective in ensuring that oil platforms continue to operate. Various companies specialize in this type of operation. NASA developed Ingenuity , a 1.8 kg (4.0 lb) helicopter used to survey Mars (along with a rover). It began service in February 2021 and was retired due to sustained rotor blade damage in January 2024 after 73 sorties. As
4266-473: The idea of vertical flight. In July 1754, Russian Mikhail Lomonosov had developed a small coaxial modeled after the Chinese top but powered by a wound-up spring device and demonstrated it to the Russian Academy of Sciences . It was powered by a spring, and was suggested as a method to lift meteorological instruments. In 1783, Christian de Launoy , and his mechanic , Bienvenu, used a coaxial version of
4345-498: The in-service and stored helicopter fleet of 38,570 with civil or government operators was led Robinson Helicopter with 24.7% followed by Airbus Helicopters with 24.4%, then Bell with 20.5 and Leonardo with 8.4%, Russian Helicopters with 7.7%, Sikorsky Aircraft with 7.2%, MD Helicopters with 3.4% and other with 2.2%. The most widespread model is the piston Robinson R44 with 5,600, then the H125/ AS350 with 3,600 units, followed by
4424-662: 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 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 at sea or in remote locations. The speed advantage over boats makes
4503-581: The late 1960s. Helicopters have also been used in films, both in front and behind the camera. The largest single non-combat helicopter operation in history was the disaster management operation following the 1986 Chernobyl nuclear disaster . Hundreds of pilots were involved in airdrop and observation missions, making dozens of sorties a day for several months. " Helitack " is the use of helicopters to combat wildland fires . The helicopters are used for aerial firefighting (water bombing) and may be fitted with tanks or carry helibuckets . Helibuckets, such as
4582-555: 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
4661-481: The monorotor design, and coaxial-rotor , tiltrotor and compound helicopters are also all flying today. Four-rotor helicopters ( quadcopters ) were pioneered as early as 1907 in France, and along with other types of multicopters , have been developed mainly for specialized applications such as commercial unmanned aerial vehicles (drones) due to the rapid expansion of drone racing and aerial photography markets in
4740-586: The nearby park, the Parco Forlanini. Emmanuel Dieuaide's steam-powered design featured counter-rotating rotors powered through a hose from a boiler on the ground. In 1887 Parisian inventor, Gustave Trouvé , built and flew a tethered electric model helicopter. In July 1901, the maiden flight of Hermann Ganswindt 's helicopter took place in Berlin-Schöneberg; this was probably the first heavier-than-air motor-driven flight carrying humans. A movie covering
4819-464: 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
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#17328581363464898-411: The power normally required to be diverted for the tail rotor to be applied fully to the main rotors, increasing the aircraft's power efficiency and lifting capacity. There are several common configurations that use the counter-rotating effect to benefit the rotorcraft: Tip jet designs let the rotor push itself through the air and avoid generating torque. The number, size and type of engine(s) used on
4977-418: The rear of the skids, one on each side, for attachment of removable wheels. The wheels must be removed prior to flight. These brackets are slightly behind the helicopter center of gravity so when the wheels are installed, the helicopter sits nose low. The wheel assembly has a pivot pin which is inserted into the skid-mounted bracket and then rotated over center to lift the rear of the skids about 2 inches leaving
5056-497: The rotor blade had failed due to overload during the crash and was not the cause of the accident and the fleet was ungrounded on 24 February 2015. The CAA left the Airworthiness Directive requiring repetitive inspections in place, however. Director of Civil Aviation Graeme Harris stated, "We don't want to see any complacency amongst operators as there is still a concern with these blades and we are waiting on test results from
5135-436: 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
5214-406: The rotor in cruise, which allows its rotation to be slowed down , thus increasing the maximum speed of the aircraft. The Lockheed AH-56A Cheyenne diverted up to 90% of its engine power to a pusher propeller during forward flight. There are three basic flight conditions for a helicopter: hover, forward flight and the transition between the two. Hovering is the most challenging part of flying
5293-422: The rotor throughout normal flight. The rotor system, or more simply rotor , is the rotating part of a helicopter that 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 horizontal thrust to counteract torque from the main rotors. The rotor consists of a mast, hub and rotor blades. The mast
5372-418: 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
5451-483: The skies. 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
5530-475: The tail rotor, such as the ducted fan (called Fenestron or FANTAIL ) and NOTAR . NOTAR provides anti-torque similar to the way a wing develops lift through the use of the Coandă effect on the tail boom. 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 anti-torque tail rotor. This allows
5609-448: The throttle is to maintain enough engine power to keep the rotor RPM within allowable limits so that the rotor produces 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 compound helicopter has an additional system for thrust and, typically, small stub fixed wings . This offloads
5688-417: 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 . The throttle controls the power produced by the engine, which is connected to the rotor by a fixed ratio transmission. The purpose of
5767-445: The two back seats, a slightly less powerful engine and a more efficient muffler. Robinson has carried out ground run testing with an aircraft diesel engine that could replace its Lycoming IO-540 avgas engine. The diesel could provide better altitude performance, a fuel burn reduced from 16 to 12 US gal (61 to 45 L) per hour and better fuel availability with no lead pollution. R44s are equipped with wheel mounts toward
5846-563: The vertical flight he had envisioned. Steam power was popular with other inventors as well. In 1877, the Italian engineer, inventor and aeronautical pioneer Enrico Forlanini developed an unmanned helicopter powered by a steam engine . It rose to a height of 13 meters (43 feet), where it remained for 20 seconds, after a vertical take-off from a park in Milan . Milan has dedicated its city airport to Enrico Forlanini, also named Linate Airport , as well as
5925-624: The world by a woman, covering a distance of 36,000 miles in 97 days. As of 2014, an R44 holds the piston speed record of 123 knots (228 km/h; 142 mph). The aircraft is operated by many private individuals, companies and flying clubs. It is also a popular choice for law enforcement agencies. R-44 Raven and Cadet models are also widely used for flight training in the US, because of their simplicity and functionality. Collegiate flight programs such as Southern Utah University, Embry Riddle, and University of North Dakota utilize these aircraft for training students in their Rotor Wing programs. The R44
6004-404: Was also the pilot of the accident helicopter. Data from Robinson R44 Raven II Pilot's Operating Handbook and FAA approved rotorcraft flight manual, dated 13 June 2005, and new Robinson R44 Raven II specifications. General characteristics Performance Related development Aircraft of comparable role, configuration, and era Related lists Helicopter A helicopter
6083-486: 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 feet) in 1901. On 5 May 1905, his helicopter reached 4 meters (13 feet) in altitude and flew for over 1,500 meters (4,900 feet). In 1908, Edison patented his own design for
6162-552: Was delivered in 1998. In January 2000, Robinson introduced the Raven with hydraulically assisted controls and adjustable pedals. In July 2002, Robinson introduced the Raven II featuring a more powerful, fuel-injected engine and wider blades, allowing a higher gross weight and improved altitude performance. During November 2015 Robinson announced the Cadet, a Raven I with a cargo area instead of
6241-457: Was found to be prone to post-accident fires due to damage to the aluminum fuel tanks, allowing fuel to leak out. In 2009, the company began installing bladder-type fuel tanks in all new R44 helicopters. It also issued Service Bulletin SB-78 on 20 December 2010, requiring R44 helicopters with all-aluminum fuel tanks to be retrofitted with bladder-type tanks to "improve the R44's fuel system's resistance to
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