98-516: The Bristol Type 171 Sycamore is an early helicopter developed and built by the helicopter division of the Bristol Aeroplane Company . The name refers to the seeds of the sycamore tree, Acer pseudoplatanus , which fall with a rotating motion. It has the distinction of being the first British helicopter to receive a certificate of airworthiness , as well as being the first British-designed helicopter to be introduced by and to serve with
196-444: 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
294-417: 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
392-740: A detachment in Brunei , to support British forces stationed there to deter further aggression by Malayan communist guerrillas. The type also saw combat service with the RAF during the Cyprus Emergency and the Aden Emergency , in addition to other operations. In December 1971, the last of the RAF's Sycamores were officially retired; this had been due to critical parts having reached the end of their fatigue life. However 32 Squadron continued to operate two Sycamores until August 1972. Fifty Sycamores were delivered to
490-597: 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. Army Air Corps (United Kingdom) The Army Air Corps ( AAC ) is the aviation arm of the British Army , first formed in 1942 during the Second World War by grouping the various airborne units of the British Army. Today, there are eight regiments (seven Regular Army and one Reserve ) of
588-459: 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
686-405: 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
784-504: 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,
882-416: 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
980-790: A new unit, the Army Air Corps. In 1958 the Saunders-Roe Skeeter 7 was introduced as the AAC's first helicopter, it was replaced by the Aérospatiale Alouette II and Westland Scout AH.1 during the early 1960s. The de Havilland Canada DHC-2 Beaver AL.1 was introduced during the 1960s along with the Agusta/Westland Sioux AH.1 in 1964. From 1970, nearly every army brigade had at least one Aviation Squadron that usually numbered twelve aircraft. The main rotor aircraft during
1078-470: 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
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#17330857807561176-489: 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
1274-441: 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
1372-417: 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
1470-429: 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
1568-687: Is a tri-service organisation consisting of civilian and military instructors that take the student from basic flying through to more advanced flying such as instrument flying, navigation, formation flying and captaincy. In service aircraft include the Airbus Helicopters H135 Juno , the AgustaWestland Wildcat AH.1, the Eurocopter AS365N3 Dauphin II , and the Boeing AH-64E Version 6 Apache . In May 2023,
1666-452: 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
1764-735: Is around 4,600. Since 2019, the AAC solely operates rotary-wing aircraft operationally. Some fixed-wing aircraft are flown with the historic flight. The AAC uses the same designation system for aircraft as the Royal Air Force and the Fleet Air Arm . The sole fixed-wing trainer is the Grob Tutor , used for Army Flying Grading. Circa 2023, AAC aviators fly four types of helicopter, and within each type there are usually several marks/variants which carry out different roles. Pilots train with No. 1 Flying Training School at RAF Shawbury . The school
1862-452: 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
1960-629: Is delivered at RAF Shawbury and Army Aviation Centre, Middle Wallop . Training Units , Army Aviation Centre, Middle Wallop The strength of the Army Air Corps is about 2,000 regular personnel, of which 500 are officers. However, the AAC draws an additional 2,600 personnel from the Royal Logistic Corps , the Royal Electrical and Mechanical Engineers and the Adjutant General's Corps . Therefore, total related Army Air Corps personnel
2058-535: 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
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#17330857807562156-665: 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
2254-411: 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
2352-540: The Airborne Forces Experimental Establishment (AFEE) at Beaulieu became available. The AFEE had been conducting its own work on the development of rotorcraft designs under the noted helicopter pioneer Raoul Hafner ; however, the successful use of Airspeed Horsa and General Aircraft Hamilcar gliders during Operation Overlord had led to helicopter development being recognised as a priority. Hafner, whose company had been acquired by Bristol
2450-558: 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
2548-572: 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
2646-517: 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
2744-693: The DHC-1 Chipmunk T.10 in a training role until its replacement by the Slingsby T67 Firefly in the 1990s. The Firefly was replaced by the Grob Tutor in 2010. During the Cold War the majority of Army Air Corps units were based in Germany and part of the British Army of the Rhine . At the beginning of 1989 the Army Air Corps structure was as follows: A further boost in the Army Air Corps' capability came in
2842-523: The Malayan Emergency , the Cyprus Emergency , and the Aden Emergency , in addition to other operations. In addition to its British military service, various models of the Sycamore were produced and operated by a number of users, including overseas military operations and civil customers. Civilian operations typically involved transportation, mountain rescue, and aerial survey work. In 1959, production of
2940-554: The Normandy landings . Once the three gliders landed, some roughly which incurred casualties, the pilots joined the glider-borne troops ( Ox & Bucks Light Infantry ) to act as infantry. The bridge was taken within ten minutes of the battle commencing and the men withstood numerous attempts by the Germans to re-capture the location. They were soon reinforced and relieved by soldiers from the 1st Special Service Brigade ( Lord Lovat ). The AAC
3038-504: The Royal Air Force (RAF), Army Air Corps (AAC), and British European Airways (BEA). Versions of the Sycamore up to and including the Mk.3A retained the standard two-seat cockpit layout, placing the pilot in the left-hand seat and the co-pilot in the right. However, on the main production model, designated Sycamore Mk.4, this seating arrangement was switched to the American practice of positioning
Bristol Sycamore - Misplaced Pages Continue
3136-452: The Royal Air Force (RAF). Typically capable of seating up to three passengers, the type was often used as a transport for both passengers and cargo alike. In RAF service, the Sycamore was normally used in the search and rescue and casualty evacuation roles. The type proved the value of rotorcraft to easily traverse inhospitable or otherwise inaccessible terrain; the Sycamore made valuable contributions to British military activities during
3234-493: 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
3332-678: The 1970s were the Westland Scout and Bell Sioux general purpose helicopters. The Sioux was replaced from 1973 by the Westland Gazelle used for Airborne reconnaissance; initially unarmed, they were converted to carry 68mm SNEB rocket pods in 1982, during the Falklands War. The Scout was replaced from 1978 by the Westland Lynx , which was capable of carrying additional firepower in the form of door gunners . Basic rotary flying training
3430-468: The AAC, as well as two independent flights and two independent squadrons deployed in support of British Army operations around the world. Regiments and flights are located in the United Kingdom, Kenya, and Canada. Some AAC squadrons provide the air assault elements of 16 Air Assault Brigade Combat Team , through Joint Aviation Command . The British Army first took to the sky during the 19th century with
3528-554: 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
3626-755: 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
3724-478: 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
3822-768: The German Federal Government. Three helicopters were produced for the Belgian Government for use in the Belgian Congo ; it had been picked due to the type's good capabilities in tropical environments, as proven during its combat use in Malaysia. The Sycamore was the second helicopter type to be used by the Australian Defence Force ; ten were delivered to the Royal Australian Navy . The Sycamore
3920-453: 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
4018-515: The Leonides engine would become the standard powerplant for all subsequent Sycamore production. On 25 April 1949, a certificate of airworthiness was granted for the Sycamore, the first such to be granted to a British helicopter. During the flight test programme, Bristol's key development pilots for the Type 171 included Charles "Sox" Hosegood and Col. Robert "Bob" Smith. In 1951, a Bristol-owned Sycamore Mk.2
Bristol Sycamore - Misplaced Pages Continue
4116-566: 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,
4214-488: The RAF and went on to serve with nine squadrons in total. Various marks of Sycamore served with the RAF; they would primarily be used as air ambulances ( Sycamore HC.10 ), for Army communications ( Sycamore HC.11 ) and for search and rescue operations (Sycamore HR.12 to Sycamore HR.14). In 1953, No. 275 Squadron, equipped with Sycamores, became the RAF's first helicopter search and rescue squadron in Great Britain. The type
4312-576: The Royal Air Force took over the helicopter support role in Brunei and thus, the Bell 212HP AH1 , previously in service, was retired. In October 2023, the Gazelle helicopter was retired from service, after 49 years in the British Army. In March 2024, the final Apache AH.1 was formally withdrawn from service. The AH-64E was declared "operationally ready" on the same day. Below is the current structure of
4410-473: The Sycamore ended after 180 rotorcraft had been completed. During the Second World War , new methods of aircraft propulsion were devised and experimented with; in particular, breakthroughs in rotary aircraft, such as gyrocopters and helicopters , were making such aircraft more practical. In 1944, Bristol established a specialised helicopter division shortly after the Allied invasion of Europe , when engineers from
4508-463: The aerial surveying of mining claims, supply missions, and the transporting of equipment across the remote Outback areas of the nation. Stored or under restoration Data from General characteristics Performance Aircraft of comparable role, configuration, and era Related lists Helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors . This allows
4606-543: The aircraft until they were retired from service on 30 June 2021. In October 2021, 29 (BATUS) Flight was placed in suspended animation, with the UK no longer providing BATUS with aviation support. The Army Air Corps adopted their first Corps Mascot – Zephyr, a bald eagle – in October 2011. The training of future Army Air Corps aircrew is delivered by the joint service UK Military Flying Training System . Elementary Flying Training
4704-550: 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
4802-461: 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
4900-435: 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
4998-677: 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
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#17330857807565096-406: 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,
5194-793: 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 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
5292-457: The conflict; however, the type was involved in a number of crashes in the region which had occurred as a result of tail or main rotor blade problems. In response, a series of blade trials were conducted prior to a modified blade design being adopted and Sycamore operations in the theatre being resumed. Following the end of most combat operations in August 1960, Sycamores remained in the region, including
5390-464: 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
5488-786: The establishment of a new branch of army aviation, the Army Air Corps. The corps initially comprised the Glider Pilot Regiment and the Parachute Battalions (subsequently the Parachute Regiment ), Air Landing Regiments , and the air observation post squadrons. In March 1944, the SAS Regiment was added to the corps. One of their most successful exploits during the war was the capture of the Caen canal and Orne river bridges by coup de main , which occurred on 6 June 1944, prior to
5586-439: 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
5684-486: 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
5782-454: The first prototype, VL958, which was powered by a 450-horsepower (340 kW) Pratt & Whitney Wasp Junior (there being no suitable engine in the Bristol range), performed the type's maiden flight . In mid-1948, the third prototype, which had been built to the improved Sycamore Mk.2 standard, was completed; this model had been fitted with a 550-horsepower (410 kW) Alvis Leonides engine,
5880-731: The form of the AgustaWestland Apache AH.1 attack helicopter, introduced in 2004. In 2006, British Apaches deployed to Afghanistan as part of the NATO International Security Assistance Force . In 2004, Britten-Norman Defender fixed wing aircraft were purchased for Afghanistan and Iraq. In April 2019, 651 Squadron personnel and aircraft, the Islander and Defender, were transferred from 5 Regiment to No. 1 Intelligence, Surveillance, and Reconnaissance Wing Royal Air Force. 651 Squadron continued to operate
5978-568: 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 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,
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#17330857807566076-505: 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
6174-473: 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
6272-498: 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
6370-662: 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
6468-581: 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
6566-555: 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
6664-404: The model; it was usually fitted with three folding canvas seats as well as a single rotating seat besides the pilot. In addition to the passenger cabin, it had a separate luggage compartment. A specialised air ambulance model of the Sycamore was developed during the early 1950s. In this configuration, up to two patients were carried inside the cabin on stretchers stacked one above the other; this
6762-586: 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
6860-464: 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
6958-401: The pilot was a swivelling seat for a medical attendant. The blades of the three-bladed main rotor were attached to the rotor head with lightweight interleaving steel plates while tie-rods carried the centrifugal tension loads. The blade levers were connected using ball joints to the arms of a control spider, the cone of which was actuated up and down by the collective pitch lever which changed
7056-628: The pilot's seat on the right. There were also a number of other developments that had featured upon the earlier versions, such as a four-door design, which had been standardised upon the Sycamore Mk.4. This version entered RAF service, receiving the military designation of HR.14. Civil versions were not marketed under the Sycamore name, they were instead known simply as the Bristol Type 171. By May 1958, over 150 Sycamores had been manufactured and four units per month were being built. The Bristol Sycamore
7154-401: The pitch of all the blades; an irreversible mechanism was used to prevent blade loads being transferred back to the control stick. The blades were supported when stationary or turning slowly by droop stops, which maintained a minimum clearance between the blade tips and the tailboom even in high winds; these stops were withdrawn above 100 rpm so that full freedom of movement for effective flight
7252-411: 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
7350-604: The rapid expansion of drone racing and aerial photography markets in 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
7448-436: 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
7546-406: 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
7644-422: 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
7742-418: 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
7840-483: 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
7938-475: 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
8036-448: 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
8134-417: 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
8232-770: The use of observation balloons. In 1911 the Air Battalion of the Royal Engineers was the first heavier-than-air British military aviation unit. The following year, the battalion was expanded into the Military Wing of the Royal Flying Corps which saw action throughout most of the First World War until 1 April 1918, when it was merged with the Royal Naval Air Service to form the Royal Air Force . Between
8330-563: 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
8428-512: The wars, the army used RAF co-operation squadrons . At the beginning of the Second World War , Royal Artillery officers, with the assistance of RAF technicians, flew Auster observation aircraft under RAF-owned air observation post (AOP) squadrons. Twelve squadrons were raised, three of which belonged to the Royal Canadian Air Force (RCAF) and each performed vital duties in many theatres. In 1942, Winston Churchill announced
8526-547: Was achieved by twisting the pitch lever. The Sycamore had a relatively high rotor speed for the era, which was claimed to give a smoother ride and be safer in the event of engine failure. From 1952 to 1955 the Sycamore was used for various trials by the Air-Sea Warfare Development Unit RAF which was stationed at RAF St. Mawgan . In April 1953, the Sycamore HR14 entered service with No. 275 Squadron of
8624-519: Was also used in a variety of civilian roles. A single example was used during the construction of the M1 motorway between London and Leeds ; the type provided support in various roles, including to perform aerial surveying, communication across various sites, the carriage of both personnel and equipment, and the mitigation of flooding on the project. Sycamores operated by Australian National Airways were routinely available for charter, performing tasks such as
8722-486: 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
8820-622: Was carried out on the Sioux in the 1970s, on the Gazelle in the 1980s and 1990s, and is currently conducted on the Eurocopter H145 / H135 through No. 1 Flying Training School RAF . Fixed-wing types in AAC service have included the Auster AOP.6 and AOP.9 and Beaver AL.1 in observation and liaison roles. In 1989, the AAC commenced operating a number of Britten-Norman Islander aircraft for surveillance and light transport duties. The corps operated
8918-437: Was different to the usual arrangement of the era of using externally-mounted "pods" for carrying patients. To provide the extra width necessary in the cabin, detachable Perspex blisters were fitted on each side of the cabin. The stretcher racks could be folded into the sides of the cabin, providing room for up to three sitting casualties instead; an electrical supply outlet was available for connecting electric blankets . Next to
9016-705: Was disbanded in 1949, with the SAS regaining independent status, while the Parachute Regiment and Glider Pilot Regiment came under the umbrella of the Glider Pilot and Parachute Corps. In 1957 the Glider Pilot and Parachute Corps was split, with the Parachute Regiment becoming an independent formation, while the Glider Pilot Regiment was merged with the Air Observation Squadrons of the Royal Artillery into
9114-418: Was drawn through a forward-facing grill to cool the gearbox before passing through the engine cowling and leaving the fuselage. The engine power was controlled by the collective pitch lever. In order to maintain the rotor speed at its required setting fuel to the engine had to be automatically varied as the rotor pitch setting commanded by the pilot changed the load on the engine; fine adjustment of engine power
9212-407: Was one of the first production helicopters to be developed. Each Sycamore was manufactured with all of the necessary fixed fittings to enable it to be quickly adapted for any of six major roles: search and rescue, air ambulance, passenger transport, freight transport, aerial crane and dual instruction; it was also used for other specialised roles. The Sycamore seated four-to-five occupants, depending on
9310-407: Was possible. The Sycamore was powered by a single Alvis Leonides piston engine of 550 hp (410 kW). The engine was mounted below and to the rear of the main rotor on a flexible mounting to reduce vibrations transmitted to the helicopter structure. It was isolated in a fireproof enclosure which was fitted with fire detection and extinguishing equipment to meet certification requirements. Air
9408-429: Was promptly appointed by the company as the head of Bristol's new helicopter division. In June 1944, work commenced on the development on a four-seat helicopter intended for both civil and military use; it was out of this programme that the Sycamore would emerge. During development, particular emphasis was assigned to the producing the necessary level of endurance of the rotorcraft's mechanical components. On 25 July 1947,
9506-621: Was used by the RAF Central Flying School for pilot training purposes. In June 1953, a Sycamore towing a large RAF Ensign led a flypast by 640 British and Commonwealth aircraft at the Coronation Review of the RAF . The Sycamore was heavily used during the Malayan Emergency (1948–1960), typically deploying Army foot patrols into the jungle. Numerous Sycamores were transferred to the Far East Air Force to participate in
9604-467: Was used during a series of deck landing trials performed on board the Royal Navy aircraft carrier HMS Triumph . An improved model of the helicopter, designated as the Sycamore Mk.3, was rapidly developed; it featured an increased capacity for five occupants, a wider fuselage and a shortened nose. A total of 23 Sycamore Mk.3s were produced, 15 of these were principally used for joint evaluation purposes by
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