92-540: The Airbus Helicopters H135 (formerly Eurocopter EC135 ) is a twin-engine civil light utility helicopter produced by Airbus Helicopters , formerly Eurocopter. It is capable of flight under instrument flight rules (IFR) and is outfitted with a digital automatic flight control system (AFCS). First flying in February 1994, it entered service in 1996. 1,400 have been delivered up to September 2020, to 300 operators in 60 countries, accumulating over 5 million flight hours. It
184-414: A core surrounded by a cladding layer, both of which are made of dielectric materials. To confine the optical signal in the core, the refractive index of the core must be greater than that of the cladding. The boundary between the core and cladding may either be abrupt, in step-index fiber , or gradual, in graded-index fiber . Light can be fed into optical fibers using lasers or LEDs . Fiber
276-411: A wavelength shifter collect scintillation light in physics experiments . Fiber-optic sights for handguns, rifles, and shotguns use pieces of optical fiber to improve the visibility of markings on the sight. An optical fiber is a cylindrical dielectric waveguide ( nonconducting waveguide) that transmits light along its axis through the process of total internal reflection. The fiber consists of
368-426: A 16,000-kilometer distance, means that there is a minimum delay of 80 milliseconds (about 1 12 {\displaystyle {\tfrac {1}{12}}} of a second) between when one caller speaks and the other hears. When light traveling in an optically dense medium hits a boundary at a steep angle of incidence (larger than the critical angle for the boundary), the light is completely reflected. This
460-423: A cladding made of pure silica, with an index of 1.444 at 1500 nm, and a core of doped silica with an index around 1.4475. The larger the index of refraction, the slower light travels in that medium. From this information, a simple rule of thumb is that a signal using optical fiber for communication will travel at around 200,000 kilometers per second. Thus a phone call carried by fiber between Sydney and New York,
552-590: A conventional flight deck or the Avionique Novelle glass cockpit – the latter allows for single pilot instrument flight rules operation. The glass cockpit is equipped with several liquid-crystal displays , including two Sextant SMD45 displays and a central panel display. The main avionics suite is supplied by Thales Group . The EC135 can be outfitted with various avionics suites from manufacturers such as Russian firm Transas Aviation and British firm Britannia 2000. The newer H135 model can be equipped with
644-464: A crucial role in military operations by providing defensive capabilities in scenarios of evacuation and cargo transportation, as well as offensive roles in fire support and surveillance. Their ability to adapt to different mission requirements contribute significantly to the success of military objectives . Fibre optic An optical fiber , or optical fibre , is a flexible glass or plastic fiber that can transmit light from one end to
736-451: A digital audio optical connection. This allows the streaming of audio over light, using the S/PDIF protocol over an optical TOSLINK connection. Fibers have many uses in remote sensing . In some applications, the fiber itself is the sensor (the fibers channel optical light to a processing device that analyzes changes in the light's characteristics). In other cases, fiber is used to connect
828-762: A four-axis autopilot, which is included as part of the Helionix avionics suite. This suite provides the H135 with a greater level of commonality with several other Airbus Helicopters-produced rotorcraft, including the H145, H160 and H175 . Earlier versions of the EC135 were equipped with a three-axis autopilot with integrated stability augmentation, featuring a First Limit Indicator (FLI), simplifying engine and torque monitoring. Cockpit touch screens can be optionally installed. Various cabin and cockpit configurations are available for
920-522: A lasting impact on structures . It is based on the principle of measuring analog attenuation. In spectroscopy , optical fiber bundles transmit light from a spectrometer to a substance that cannot be placed inside the spectrometer itself, in order to analyze its composition. A spectrometer analyzes substances by bouncing light off and through them. By using fibers, a spectrometer can be used to study objects remotely. An optical fiber doped with certain rare-earth elements such as erbium can be used as
1012-616: A mountain rescue configuration, the cabin can simultaneously accommodate two stretchers as well as the pilot, anaesthetist, winch operator, mechanic and mountain rescue specialist. Airbus Helicopters has promoted the airframe's various configurations as possessing "unique adaptability" for various missions, including utility work, commercial transportation, and training roles. Equipment for the law enforcement role include external loudspeakers , rappelling system, search lights with laser pointers , left or right-mounted hoists , and electro-optical sensors . For offshore oil & gas operations,
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#17327728689811104-423: A network in an office building (see fiber to the office ), fiber-optic cabling can save space in cable ducts. This is because a single fiber can carry much more data than electrical cables such as standard category 5 cable , which typically runs at 100 Mbit/s or 1 Gbit/s speeds. Fibers are often also used for short-distance connections between devices. For example, most high-definition televisions offer
1196-595: A one-engine inoperative training mode, and full ground simulators, may be selected. Deliveries started in August 1996, when two helicopters, 0005 and 0006, were handed over to German emergency aero medical service provider Deutsche Rettungsflugwacht . The 100th EC135 was handed over to the Bavarian police force in June 1999, by which point the worldwide fleet had accumulated approximately 30,000 flight hours. In September 2003,
1288-401: A pair of Turbomeca Arrius 2B or Pratt & Whitney Canada PW206B engines, dependent on customer's preference, which gives either a T or a P, respectively, in the variant name. The main rotor is of a four-bladed, hingeless fiber-composite design. Progressive improvements to the main rotor have increased its performance and reduced maintenance costs since the type's introduction. The EC135 is
1380-624: A relocated horizontal stabilizer outside the main rotor's downwash, an active rudder, and new water-based external paint; these changes were aimed at cutting fuel consumption by 40%. In December 2014, the single-engine operations portion of the Bluecopter tests were delayed to summer 2016 to make necessary avionics changes, such as to the engine's FADEC systems. In March 2007, at the NBAA in Atlanta , Eurocopter unveiled ' L'Hélicoptère par Hermès ,
1472-474: A sensor to a measurement system. Optical fibers can be used as sensors to measure strain , temperature , pressure , and other quantities by modifying a fiber so that the property being measured modulates the intensity , phase , polarization , wavelength , or transit time of light in the fiber. Sensors that vary the intensity of light are the simplest since only a simple source and detector are required. A particularly useful feature of such fiber optic sensors
1564-486: A special-edition VIP model designed by Hermès International, S.A. . It features a customized luxury four-place main cabin, a sliding glass partition, a corporate baggage hold, redesigned skid landing gear and other external changes. The launch customer for the type is Falcon Aviation Services (FAS), based in Abu Dhabi , United Arab Emirates. In July 2014, Airbus Helicopters made further personalization options available for
1656-649: A target without a clear line-of-sight path. Many microscopes use fiber-optic light sources to provide intense illumination of samples being studied. Optical fiber is also used in imaging optics. A coherent bundle of fibers is used, sometimes along with lenses, for a long, thin imaging device called an endoscope , which is used to view objects through a small hole. Medical endoscopes are used for minimally invasive exploratory or surgical procedures. Industrial endoscopes (see fiberscope or borescope ) are used for inspecting anything hard to reach, such as jet engine interiors. In some buildings, optical fibers route sunlight from
1748-524: A transparent cladding. Later that same year, Harold Hopkins and Narinder Singh Kapany at Imperial College in London succeeded in making image-transmitting bundles with over 10,000 fibers, and subsequently achieved image transmission through a 75 cm long bundle which combined several thousand fibers. The first practical fiber optic semi-flexible gastroscope was patented by Basil Hirschowitz , C. Wilbur Peters, and Lawrence E. Curtiss, researchers at
1840-468: Is a mechanical splice , where the ends of the fibers are held in contact by mechanical force. Temporary or semi-permanent connections are made by means of specialized optical fiber connectors . The field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics . The term was coined by Indian-American physicist Narinder Singh Kapany . Daniel Colladon and Jacques Babinet first demonstrated
1932-534: Is a development of the earlier Messerschmitt-Bölkow-Blohm (MBB) Bo 105 . The H135 started development prior to the formation of Eurocopter, under Messerschmitt-Bölkow-Blohm (MBB) under the designation Bo 108 in the 1970s. MBB developed it in partnership with Aérospatiale , the Bo 108 was initially intended to be a technology demonstrator, combining attributes of the successful MBB Bo 105 with new advances and an aerodynamically streamlined design. Technologies included on
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#17327728689812024-799: Is a multi-purpose helicopter capable of pursuing a wide array of tasks. They have proven useful in both civilian and military operations, with versatility being their defining trait. Helicopters play a crucial role in various aspects of civilian safety. Police and fire rescue aircraft demonstrate exceptional versatility across a broad spectrum of task. Common applications for civilian utility include traffic surveillance, medical evacuations , news coverage, and search and rescue missions. Recently, usage has been extended to air evacuations , air and water pollution control, emergency cargo transportation (including blood, organs, and special equipment), and as helitankers in aerial firefighting . Traditionally, helicopters with three placed reciprocating engines , such as
2116-453: Is a way of measuring the speed of light in a material. Light travels fastest in a vacuum , such as in outer space. The speed of light in vacuum is about 300,000 kilometers (186,000 miles) per second. The refractive index of a medium is calculated by dividing the speed of light in vacuum by the speed of light in that medium. The refractive index of vacuum is therefore 1, by definition. A typical single-mode fiber used for telecommunications has
2208-451: Is available as an option and can be applied retroactively to all Helionix-equipped H135s. In December 2020, Airbus certified a new single-pilot IFR Helionix cockpit for its H135 helicopters. The modified cockpit allows customers to choose whether to remove the copilot side of the instrument panel to increase the field of view or keep it to install specific STC equipment. The H135 is a twin-engine rotorcraft. It can be alternatively powered by
2300-411: Is bent towards the perpendicular ... When the ray passes from water to air it is bent from the perpendicular... If the angle which the ray in water encloses with the perpendicular to the surface be greater than 48 degrees, the ray will not quit the water at all: it will be totally reflected at the surface... The angle which marks the limit where total reflection begins is called the limiting angle of
2392-412: Is called multi-mode fiber , from the electromagnetic analysis (see below). In a step-index multi-mode fiber, rays of light are guided along the fiber core by total internal reflection. Rays that meet the core-cladding boundary at an angle (measured relative to a line normal to the boundary) greater than the critical angle for this boundary, are completely reflected. The critical angle is determined by
2484-418: Is called total internal reflection . This effect is used in optical fibers to confine light in the core. Most modern optical fiber is weakly guiding , meaning that the difference in refractive index between the core and the cladding is very small (typically less than 1%). Light travels through the fiber core, bouncing back and forth off the boundary between the core and cladding. Because the light must strike
2576-507: Is designed for use in the near infrared . Multi-mode fiber, by comparison, is manufactured with core diameters as small as 50 micrometers and as large as hundreds of micrometers. Some special-purpose optical fiber is constructed with a non-cylindrical core or cladding layer, usually with an elliptical or rectangular cross-section. These include polarization-maintaining fiber used in fiber optic sensors and fiber designed to suppress whispering gallery mode propagation. Photonic-crystal fiber
2668-565: Is far less than in electrical copper cables, leading to long-haul fiber connections with repeater distances of 70–150 kilometers (43–93 mi). Two teams, led by David N. Payne of the University of Southampton and Emmanuel Desurvire at Bell Labs , developed the erbium-doped fiber amplifier , which reduced the cost of long-distance fiber systems by reducing or eliminating optical-electrical-optical repeaters, in 1986 and 1987 respectively. The emerging field of photonic crystals led to
2760-564: Is immune to electrical interference as there is no cross-talk between signals in different cables and no pickup of environmental noise. Information traveling inside the optical fiber is even immune to electromagnetic pulses generated by nuclear devices. Fiber cables do not conduct electricity, which makes fiber useful for protecting communications equipment in high voltage environments such as power generation facilities or applications prone to lightning strikes. The electrical isolation also prevents problems with ground loops . Because there
2852-418: Is important in fiber optic communication. This is more complex than joining electrical wire or cable and involves careful cleaving of the fibers, precise alignment of the fiber cores, and the coupling of these aligned cores. For applications that demand a permanent connection a fusion splice is common. In this technique, an electric arc is used to melt the ends of the fibers together. Another common technique
Eurocopter EC135 - Misplaced Pages Continue
2944-611: Is kept in the core by the phenomenon of total internal reflection which causes the fiber to act as a waveguide . Fibers that support many propagation paths or transverse modes are called multi-mode fibers , while those that support a single mode are called single-mode fibers (SMF). Multi-mode fibers generally have a wider core diameter and are used for short-distance communication links and for applications where high power must be transmitted. Single-mode fibers are used for most communication links longer than 1,050 meters (3,440 ft). Being able to join optical fibers with low loss
3036-405: Is made with a regular pattern of index variation (often in the form of cylindrical holes that run along the length of the fiber). Such fiber uses diffraction effects instead of or in addition to total internal reflection, to confine light to the fiber's core. The properties of the fiber can be tailored to a wide variety of applications. Attenuation in fiber optics, also known as transmission loss,
3128-689: Is mainly used for air medical transport ( medevac ), corporate transport, law enforcement, offshore wind support, and military flight training. Half of them are in Europe and a quarter in North America. The H135M, certified under the name Eurocopter EC635 , is a military variant, so the overall design is known as the Airbus Helicopters H135 and the military version, as the Airbus Helicopters H135M. The EC135/H135
3220-412: Is monitored and analyzed for disturbances. This return signal is digitally processed to detect disturbances and trip an alarm if an intrusion has occurred. Optical fibers are widely used as components of optical chemical sensors and optical biosensors . Optical fiber can be used to transmit power using a photovoltaic cell to convert the light into electricity. While this method of power transmission
3312-439: Is no electricity in optical cables that could potentially generate sparks, they can be used in environments where explosive fumes are present. Wiretapping (in this case, fiber tapping ) is more difficult compared to electrical connections. Fiber cables are not targeted for metal theft . In contrast, copper cable systems use large amounts of copper and have been targeted since the 2000s commodities boom . The refractive index
3404-478: Is not as efficient as conventional ones, it is especially useful in situations where it is desirable not to have a metallic conductor as in the case of use near MRI machines, which produce strong magnetic fields. Other examples are for powering electronics in high-powered antenna elements and measurement devices used in high-voltage transmission equipment. Optical fibers are used as light guides in medical and other applications where bright light needs to be shone on
3496-741: Is set within Navy's 723 Squadron at HMAS Albatross . In 2024, after the retirement of the MRH-90 Taipan helicopter, the Australian government announced that it would lease 5 H135T3 (Juno) from the United Kingdom Ministry of Defence for five years to maintain "essential training requirements" for Australian Army pilots. The helicopters will be based at the Oakey Army Aviation Centre . In 2016, half of
3588-418: Is that they can, if required, provide distributed sensing over distances of up to one meter. Distributed acoustic sensing is one example of this. In contrast, highly localized measurements can be provided by integrating miniaturized sensing elements with the tip of the fiber. These can be implemented by various micro- and nanofabrication technologies, such that they do not exceed the microscopic boundary of
3680-422: Is the numerical aperture (NA) of the fiber. Fiber with a larger NA requires less precision to splice and work with than fiber with a smaller NA. The size of this acceptance cone is a function of the refractive index difference between the fiber's core and cladding. Single-mode fiber has a small NA. Fiber with large core diameter (greater than 10 micrometers) may be analyzed by geometrical optics . Such fiber
3772-474: Is the measurement of temperature inside jet engines by using a fiber to transmit radiation into a pyrometer outside the engine. Extrinsic sensors can be used in the same way to measure the internal temperature of electrical transformers , where the extreme electromagnetic fields present make other measurement techniques impossible. Extrinsic sensors measure vibration, rotation, displacement, velocity, acceleration, torque, and torsion. A solid-state version of
Eurocopter EC135 - Misplaced Pages Continue
3864-428: Is the reduction in the intensity of the light signal as it travels through the transmission medium. Attenuation coefficients in fiber optics are usually expressed in units of dB/km. The medium is usually a fiber of silica glass that confines the incident light beam within. Attenuation is an important factor limiting the transmission of a digital signal across large distances. Thus, much research has gone into both limiting
3956-484: Is typical in deployed systems. Through the use of wavelength-division multiplexing (WDM), each fiber can carry many independent channels, each using a different wavelength of light. The net data rate (data rate without overhead bytes) per fiber is the per-channel data rate reduced by the forward error correction (FEC) overhead, multiplied by the number of channels (usually up to 80 in commercial dense WDM systems as of 2008 ). For short-distance applications, such as
4048-402: Is used as a medium for telecommunication and computer networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because infrared light propagates through the fiber with much lower attenuation compared to electricity in electrical cables. This allows long distances to be spanned with few repeaters . 10 or 40 Gbit/s
4140-588: The 47G Series and the Hughes 300C were the primary choices for civilian use. However, the preference has been shifted towards turbine engines . The FH-100 and the Bell 206A JetRanger are examples of turbine engine helicopters which have proven to be more effective in operational scenarios. The arising issue with civilian use helicopters is the price tag of the turbine engine helicopters. With initial cost being around $ 100,000, difficulties are posed when budgeting for
4232-662: The Greater Gabbard offshore wind farm. The EC135 has been used in Denmark to support the Horns Rev offshore wind farm. By 2013, over 10,000 successful personnel transfers have taken place using the type. In Mexico, Apoyo Logístico Aéreo has operated a fleet of EC135s for servicing the extensive oil and gas offshore platforms in the Gulf of Mexico . In 2013, it was reported that the EC135 was currently providing roughly 25% of
4324-742: The School of Army Aviation in Bückeburg . These have had an average operational availability in excess of 95 per cent. In 2014, the German Army noted that there was potential for vibration-induced rotor cracking during autorotation training, shortening the life of the main rotor. 13 EC135 trainers have been procured by the Japanese Maritime Self-Defense Force , they have been designed as the TH-135. In December 2014,
4416-471: The University of Michigan , in 1956. In the process of developing the gastroscope, Curtiss produced the first glass-clad fibers; previous optical fibers had relied on air or impractical oils and waxes as the low-index cladding material. Kapany coined the term fiber optics after writing a 1960 article in Scientific American that introduced the topic to a wide audience. He subsequently wrote
4508-405: The gain medium of a fiber laser or optical amplifier . Rare-earth-doped optical fibers can be used to provide signal amplification by splicing a short section of doped fiber into a regular (undoped) optical fiber line. The doped fiber is optically pumped with a second laser wavelength that is coupled into the line in addition to the signal wave. Both wavelengths of light are transmitted through
4600-530: The 300th EC135 was handed over to UK-based McAlpine Helicopters. At this point, the EC135 was the best selling new light twin-engine helicopter in the UK market. In 2011, Eurocopter announced that the 1,000th EC135 to be produced had been delivered to German operator ADAC , roughly 15 years since the start of production. In 2012, Flying magazine recognised the EC135 as being "the industry's best selling twin-engine helicopter". The world fleet leader in flight hours for
4692-533: The Bo ;108 included the first full-authority digital engine controls ( FADEC ) on a helicopter, a hingeless main rotor, and the adoption of a new transmission. The first prototype made its first flight on 17 October 1988, powered by two Allison 250-C20R /1 engines. A second Bo 108 followed in June 1991, this time with two Turbomeca TM319-1B Arrius engines. Unlike later production aircraft, both technology demonstrators flew with conventional tail rotors. In
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#17327728689814784-595: The EC135 had considerable appeal to a wide range of operators. European JAA certification was achieved in June 1996, with FAA approval following in July. In December 1999, the EC135 was granted single-pilot IFR (SPIFR) certification by Germany's Luftfahrt-Bundesamt (LBA). In December 2000, the United Kingdom's Civil Aviation Authority also gave the EC135 SPIFR certification. In 2000, Eurocopter announced
4876-569: The EC135 l'Helicoptere par Hermes. In 2011, Eurocopter formalised a license manufacturing agreement with Zhong-Ou International Group to produce the EC135 luxury helicopter in Zhejiang Province, China. In October 2015, a letter of intent between Airbus Helicopters and Ecopark was signed for the establishment of a final assembly line (FAL) in Qingdao Province, China. A related $ 1.1 billion order for 100 Chinese-assembled H135s
4968-418: The EC135, depending on the role performed and the operator's preferences. It can hold up to five passengers and a pilot when configured with a standard executive interior, or seven passengers in a dense corporate interior. Modular multi-role interiors that allow the main cabin area to be quickly changed and re-equipped are available. The main cabin of the EC135 is accessed either by large doors on either side of
5060-914: The EC135s operating in service were engaged in emergency medical services operations, 17% in air transport , 16% in public services (typically law enforcement ), 10% in military missions, 4% in offshore operations (typically offshore wind power inspection), and the remaining 3% in military training. The 1,400th was delivered in September 2020, as over 300 customers in 60 countries accumulated more than 4.5 million flight hours. Most are in Europe (641), followed by North America (316) and Asia (195). [REDACTED] Canada Data from Eurocopter EC135 2008 Tech Data book General characteristics Performance Related development Aircraft of comparable role, configuration, and era Related lists Utility helicopter A utility helicopter
5152-493: The Heli-Expo convention at Las Vegas , at which prospective buyers were reportedly impressed with its appearance and performance figures. Another feature which became apparent upon entering service was the low noise levels produced, in part due to its Fenestron tail, the EC135 was the quietest aircraft in its class for more than 15 years. Despite the helicopter's design being primarily oriented towards emergency medical operators,
5244-777: The acquisition of up to 20 H135 for public leasing purposes. In 2017, the Royal Air Force received the first 2 of 29 H135s designated as Juno HT.1s for the UK Military Flying Training System with training provided by Ascent Flight Training. In 2018, the Australian Defence Force established the Joint Helicopter School operating 15 EC135T2+ procured under Project Air 9000 Phase 7 to train both Australian Army and Royal Australian Navy pilots. The school
5336-564: The attenuation in fibers available at the time was caused by impurities that could be removed, rather than by fundamental physical effects such as scattering. They correctly and systematically theorized the light-loss properties for optical fiber and pointed out the right material to use for such fibers— silica glass with high purity. This discovery earned Kao the Nobel Prize in Physics in 2009. The crucial attenuation limit of 20 dB/km
5428-416: The boundary with an angle greater than the critical angle, only light that enters the fiber within a certain range of angles can travel down the fiber without leaking out. This range of angles is called the acceptance cone of the fiber. There is a maximum angle from the fiber axis at which light may enter the fiber so that it will propagate, or travel, in the core of the fiber. The sine of this maximum angle
5520-405: The cabin or by clamshell doors located at the rear of the cabin, directly underneath the aircraft's tail boom. The clamshell doors are particularly attractive to emergency medical services (EMS) and cargo operators. Medical facilities can be installed in the cabin, such as in-flight intensive care stations (including resuscitation functionality), incubators , and hygiene-convenient flooring. In
5612-457: The cameras had to be supervised by someone with an appropriate security clearance. Charles K. Kao and George A. Hockham of the British company Standard Telephones and Cables (STC) were the first to promote the idea that the attenuation in optical fibers could be reduced below 20 decibels per kilometer (dB/km), making fibers a practical communication medium, in 1965. They proposed that
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#17327728689815704-416: The case of a fiberscope . Specially designed fibers are also used for a variety of other applications, such as fiber optic sensors and fiber lasers . Glass optical fibers are typically made by drawing , while plastic fibers can be made either by drawing or by extrusion . Optical fibers typically include a core surrounded by a transparent cladding material with a lower index of refraction . Light
5796-407: The core-cladding boundary. The resulting curved paths reduce multi-path dispersion because high-angle rays pass more through the lower-index periphery of the core, rather than the high-index center. The index profile is chosen to minimize the difference in axial propagation speeds of the various rays in the fiber. This ideal index profile is very close to a parabolic relationship between the index and
5888-442: The development in 1991 of photonic-crystal fiber , which guides light by diffraction from a periodic structure, rather than by total internal reflection. The first photonic crystal fibers became commercially available in 2000. Photonic crystal fibers can carry higher power than conventional fibers and their wavelength-dependent properties can be manipulated to improve performance. These fibers can have hollow cores. Optical fiber
5980-467: The difference in the index of refraction between the core and cladding materials. Rays that meet the boundary at a low angle are refracted from the core into the cladding where they terminate. The critical angle determines the acceptance angle of the fiber, often reported as a numerical aperture . A high numerical aperture allows light to propagate down the fiber in rays both close to the axis and at various angles, allowing efficient coupling of light into
6072-445: The distance from the axis. Fiber with a core diameter less than about ten times the wavelength of the propagating light cannot be modeled using geometric optics. Instead, it must be analyzed as an electromagnetic waveguide structure, according to Maxwell's equations as reduced to the electromagnetic wave equation . As an optical waveguide, the fiber supports one or more confined transverse modes by which light can propagate along
6164-621: The doped fiber, which transfers energy from the second pump wavelength to the signal wave. The process that causes the amplification is stimulated emission . Optical fiber is also widely exploited as a nonlinear medium. The glass medium supports a host of nonlinear optical interactions, and the long interaction lengths possible in fiber facilitate a variety of phenomena, which are harnessed for applications and fundamental investigation. Conversely, fiber nonlinearity can have deleterious effects on optical signals, and measures are often required to minimize such unwanted effects. Optical fibers doped with
6256-424: The fiber tip, allowing for such applications as insertion into blood vessels via hypodermic needle. Extrinsic fiber optic sensors use an optical fiber cable , normally a multi-mode one, to transmit modulated light from either a non-fiber optical sensor—or an electronic sensor connected to an optical transmitter. A major benefit of extrinsic sensors is their ability to reach otherwise inaccessible places. An example
6348-404: The fiber. Fiber supporting only one mode is called single-mode . The waveguide analysis shows that the light energy in the fiber is not completely confined in the core. Instead, especially in single-mode fibers, a significant fraction of the energy in the bound mode travels in the cladding as an evanescent wave . The most common type of single-mode fiber has a core diameter of 8–10 micrometers and
6440-438: The fiber. However, this high numerical aperture increases the amount of dispersion as rays at different angles have different path lengths and therefore take different amounts of time to traverse the fiber. In graded-index fiber, the index of refraction in the core decreases continuously between the axis and the cladding. This causes light rays to bend smoothly as they approach the cladding, rather than reflecting abruptly from
6532-493: The first book about the new field. The first working fiber-optic data transmission system was demonstrated by German physicist Manfred Börner at Telefunken Research Labs in Ulm in 1965, followed by the first patent application for this technology in 1966. In 1968, NASA used fiber optics in the television cameras that were sent to the moon. At the time, the use in the cameras was classified confidential , and employees handling
6624-583: The first production EC135 T3 entered service with Aiut Alpin Dolomites, a mountain rescue operator based in Italy. In June 2015, Airbus Helicopters delivered the first retrofitted H135 from the earlier EC135 standard. Changes include an enlarged main rotor, relocated engine air intakes, elevated engine performance, and the horizontal stabiliser's endplates removed and its span increased. In October 2015, Waypoint Leasing and Airbus Helicopters signed an agreement for
6716-510: The guiding of light by refraction, the principle that makes fiber optics possible, in Paris in the early 1840s. John Tyndall included a demonstration of it in his public lectures in London , 12 years later. Tyndall also wrote about the property of total internal reflection in an introductory book about the nature of light in 1870: When the light passes from air into water, the refracted ray
6808-469: The gyroscope, using the interference of light, has been developed. The fiber optic gyroscope (FOG) has no moving parts and exploits the Sagnac effect to detect mechanical rotation. Common uses for fiber optic sensors include advanced intrusion detection security systems . The light is transmitted along a fiber optic sensor cable placed on a fence, pipeline, or communication cabling, and the returned signal
6900-498: The late 1990s, the design was revised with the introduction of the Fenestron tail rotor system, an advanced rigid main rotor, composite materials, and resonance isolation systems. It was decided to pursue a full certification program, resulting in the production of two pre-production prototypes. At the same time, the Bo 108 was given a new designation of EC135, to correspond with the newly created Eurocopter company. At this point, it
6992-532: The main rotor, and changes to the fenstron anti-torque tail device. The EC135 T3 was introduced to service in December 2014. In December 2020, the H135 helicopter family EASA has certified a new Alternate Gross Weight (AGW). With the new AGW, the maximum takeoff weight has been increased up to 265 lb (120 kg) and payload. This modification can be used to increase range by up to 75 nm or endurance by up to 40 minutes under standard conditions. The new AGW
7084-413: The medium. For water this angle is 48°27′, for flint glass it is 38°41′, while for a diamond it is 23°42′. In the late 19th century, a team of Viennese doctors guided light through bent glass rods to illuminate body cavities. Practical applications such as close internal illumination during dentistry followed, early in the twentieth century. Image transmission through tubes was demonstrated independently by
7176-576: The necessary modifications. Such modifications include night vision capabilities , infrared , and radar . In military terms, a utility helicopter is an aircraft designed to transport troops, but is versatile in performing various combat roles. These tasks include command and control , logistics, casualty evacuation, and fire support . The defining characteristics of these helicopters are lightweight frames capable of quick maneuvers , and space, for transporting troops and cargo. Common types of cargo include ammunition, weapons, and food. These aircraft play
7268-507: The other. Such fibers find wide usage in fiber-optic communications , where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss and are immune to electromagnetic interference . Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in
7360-442: The quietest helicopter in its class, featuring an anti- resonance isolation system to dampen vibration from the main rotor. The type's Fenestron anti-torque device can be actively regulated via a HI NR rotor optimization mode, which provides for greater controllability during higher weight take-off and landings. It is capable of performing Category A operations throughout its full flight envelope. The EC135 can be equipped with either
7452-416: The radio experimenter Clarence Hansell and the television pioneer John Logie Baird in the 1920s. In the 1930s, Heinrich Lamm showed that one could transmit images through a bundle of unclad optical fibers and used it for internal medical examinations, but his work was largely forgotten. In 1953, Dutch scientist Bram van Heel first demonstrated image transmission through bundles of optical fibers with
7544-431: The roof to other parts of the building (see nonimaging optics ). Optical-fiber lamps are used for illumination in decorative applications, including signs , art , toys and artificial Christmas trees . Optical fiber is an intrinsic part of the light-transmitting concrete building product LiTraCon . Optical fiber can also be used in structural health monitoring . This type of sensor can detect stresses that may have
7636-488: The rotorcraft can be fitted with weather/search radars , emergency floatation aids, including an automated external life raft, energy-absorbent seating, class-D certified external hoists, and crash-resistant fuel tanks . An external hook can be installed to carry underslung loads of up to 272 kg for cargo missions. In a training capacity, features such a light aircraft recording system for post-flight analysis, intuitive human-machine interface, specific training modules, and
7728-568: The speed of manufacture to over 50 meters per second, making optical fiber cables cheaper than traditional copper ones. These innovations ushered in the era of optical fiber telecommunication. The Italian research center CSELT worked with Corning to develop practical optical fiber cables, resulting in the first metropolitan fiber optic cable being deployed in Turin in 1977. CSELT also developed an early technique for splicing optical fibers, called Springroove. Attenuation in modern optical cables
7820-649: The start of certification work on the EC135P2, powered by the Pratt & Whitney Canada PW206B2, offering improved single-engine performance and 30-second emergency power. The LBA certification was achieved in July 2001, and the first EC135 with the new engines was handed over to the Swedish Police Authority in August 2001. In September 2002, the EC135T2 equipped with the improved Turbomeca Arrius 2B2
7912-630: The type is G-NESV (s/n 0067), operated by Cleveland Police Air Operations Unit based at Durham Tees Valley Airport , UK. Originally delivered to the North East Air Support Unit in April 1999, it was the first EC135 worldwide to attain 10,000 flying hours. In 2009, the EC135 was the first aircraft selected for offshore wind support in the UK, after the Civil Aviation Authority approved helicopter operations to
8004-507: The world's total emergency medic services flights, and that over 500 EC135s have been delivered to in an aeromedical configuration. By late 2013, during which a brief grounding of the type was instigated due to safety concerns of fuel gauges, the EC135 made up half of the UK's operational air ambulance fleet. In October 2014, the first EC135 air ambulance was delivered in the Chinese market. The German Army operates 19 H135s as basic trainers at
8096-636: Was announced in the same month. The majority of assembly work on the type remains at Airbus Helicopter's Donauwörth facility. Construction of the FAL started in May 2017, and opened for production in April 2019. In January 2016, the Ural Works of Civil Aviation (UWCA), a division of Rostec , signed an agreement to build the H135 under licence at the firm's facility in Yekaterinburg , Russia. In May 2016, it
8188-480: Was decided that the EC135 should be developed with the option of being powered by two competing engines, the Turbomeca Arrius 2B and the Pratt & Whitney Canada PW206B engines. Two pre-production prototypes were built in 1994 powered by either engine, both powerplants proved to be successful and were used on subsequent production aircraft. In January 1995, the EC135 made its first public appearance at
8280-675: Was first achieved in 1970 by researchers Robert D. Maurer , Donald Keck , Peter C. Schultz , and Frank Zimar working for American glass maker Corning Glass Works . They demonstrated a fiber with 17 dB/km attenuation by doping silica glass with titanium . A few years later they produced a fiber with only 4 dB/km attenuation using germanium dioxide as the core dopant. In 1981, General Electric produced fused quartz ingots that could be drawn into strands 25 miles (40 km) long. Initially, high-quality optical fibers could only be manufactured at 2 meters per second. Chemical engineer Thomas Mensah joined Corning in 1983 and increased
8372-529: Was made available, providing for improved single-engine performance. In 2002, the EC135 active control technology demonstrator/flying helicopter simulator (ACT/FHS), a research aircraft designed to test fibre optic -based flight control systems, undertook its first flight. In 2014, Airbus Helicopters began flying the Bluecopter demonstrator aircraft, built to explore more efficient design elements, including economy-optimised single-engine operations, Blue Edge swept rotor blades to reduce noise and increase efficiency,
8464-461: Was reported that Russian production of the H135 was anticipated to begin in 2017, following the receipt of Russian type certification . Russian manufacturers may be incorporated in the global supply chain. Two variants, the EC135 T3 and EC135 P3, were developed with improved high altitude and hover performance. Changes include repositioned air intakes to the engines, wider blades being installed on
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