View source for Radio-controlled helicopter

{{Short description|Model aircraft}}
[[Image:Align Trex 250 RC Helicopter flying inverted.jpg|thumb|right|Electric Trex 250 micro heli flying inverted]]
[[Image:Venom Ocean Rescue.jpg|thumb|right|Electric-powered Venom Air Corps Ocean Rescue]]
[[Image:Align T-REX 2386.jpg|thumb|right|Electric-powered [[T-Rex (RC helicopter)#T-Rex 450|Align T-rex 450SE]]]]
[[File:Blade 400 action1.jpg|thumb|right|Electric-powered [[E-flite]] Blade 400 3D]]
[[File:Syma-s107.jpg|thumb|right|Electric-powered Syma S107]]
[[File:Axe micro with phone.jpg|right|thumb|This Heli-Max Axe Micro CX model helicopter is an example of a micro-sized [[coaxial rotors|coaxial]] model.  Note the size comparison with the cellular telephone at right.]]

A '''radio-controlled helicopter''' (also ''[[Radio control|RC]] helicopter'') is [[model aircraft]] which is distinct from an [[Radio controlled aircraft|RC airplane]] because of the differences in construction, [[aerodynamics]], and flight training. Several basic designs of RC helicopters exist, of which some (such as those with [[collective pitch]] control) are more maneuverable than others. The more maneuverable designs are often harder to fly, but benefit from greater [[aerobatics|aerobatic]] capabilities.<ref name="RCHF-electric" >{{cite web | url=http://www.rchelicopterfun.com/electric-helicopters.html | title=Electric Helicopters | access-date=28 October 2014}}</ref>

Flight controls allow [[Aircraft pilot|pilot]]s to control the collective (or throttle, on fixed pitch helicopters), the cyclic controls ([[Pitch (flight)|pitch]] and [[roll (flight)|roll]]), and the tail rotor ([[yaw (flight)|yaw]]).<ref>{{cite web | url=http://www.helifever.com/videos/operating-rc-radio-controls-detailed-tutorial/ | title=Operating R/C Radio Controls | access-date=28 October 2014 | archive-date=7 August 2012 | archive-url=https://web.archive.org/web/20120807001021/http://www.helifever.com/videos/operating-rc-radio-controls-detailed-tutorial | url-status=dead }}</ref> Controlling these in unison enables the helicopter to perform the same maneuvers as full-sized helicopters, such as hovering and backwards flight, and many other maneuvers that full-sized helicopters cannot, such as inverted flight (where collective pitch control provides negative blade pitch to hold heli up inverted, and pitch/yaw controls must be reversed by pilot).<ref name=Controls>{{cite web | url=http://www.rchelicopterfun.com/rc-helicopter-controls.html | title=RC Helicopter Controls | access-date=28 October 2014}}</ref>

The various helicopter controls are affected by means of small [[RC Servo|servo]] motors, commonly known as servos. A [[Vibrating structure gyroscope|solid-state gyroscope]] sensor is typically used on the tail rotor ([[yaw (flight)|yaw]]) control to counter wind- and torque-reaction-induced tail movement.<ref>{{cite web | url=http://www.rchelicopterfun.com/rc-helicopter-gyro.html | title=Understanding RC Heli Gyros | access-date=28 October 2014}}</ref>  Most newer helicopters have gyro-stabilization on the other 2 axis of rotation ([[pitch (aviation)|pitch]] and [[roll (flight)|roll]]) as well.  Such 3-axis gyro is typically called a ''flybarless controller'', so-called because it eliminates the need for a mechanical [[Helicopter rotor#Flybar (stabilizer bar)|flybar]].<ref>{{cite web | url=http://www.rchelicopterfun.com/flybarless.html | title=Flybarless Controller | access-date=28 October 2014}}</ref>

The engines typically used to be methanol-powered two-stroke motors, but electric [[brushless motor]]s combined with a high-performance [[lithium polymer battery]] (LiPo) are now more common and provide improved efficiency, performance, and lifespan compared to brushed motors, while decreasing prices bring them within reach of hobbyists. Gasoline and jet turbine engines are also used.<ref>{{cite web|title=Buyers Guide|url=http://www.rcmods.co.uk/buyers_guide.php|work=Intermediate/Advanced Outdoor Models|publisher=RCMods|access-date=29 May 2013|url-status=dead|archive-url=https://web.archive.org/web/20130709135909/http://www.rcmods.co.uk/buyers_guide.php|archive-date=9 July 2013}}</ref>

Just like full sized helicopters, model helicopter rotors turn at high speeds and can cause severe injuries. Several deaths have occurred, some as recently as 2013.

==Types of R/C helicopters==
Common power sources of remote control helicopters are [[glow fuel]] (also called nitro fuel, [[nitromethane#As an engine fuel|nitromethane]]-[[methanol]]), electric batteries, gasoline (petrol) and turbine engines.  For the first 40 years, glow fuel helicopters were the most common type produced.  However, in the last 10 years, electric powered helicopters have matured to a point where power and flight times are better, but typically not as long as glow fuel helicopters.

There have been two main types of systems to control the main rotors, mechanical mixing and [[electronic cyclic/collective pitch mixing]] (eCCPM).  Most earlier helicopters used mechanical mixing.  Today, nearly all R/C helicopter use eCCPM.<ref>{{cite news|last1=Iszech|first1=Pavel|title=RC Helicopters Archieven|url=http://dronevinder.nl/shop/rc-helicopters/|access-date=2 January 2017|work=DroneVinder|date=20 January 2010|language=nl-NL|archive-date=3 January 2017|archive-url=https://web.archive.org/web/20170103094136/http://dronevinder.nl/shop/rc-helicopters/|url-status=dead}}</ref>

Practical electric helicopters are a recent development but have rapidly developed and become more common, overtaking glow fuel helicopters in common use. [[Turbine]] helicopters are also increasing in popularity, although the high cost puts them out of reach of most people.

===Internal Combustion (Nitro, Gas)===
The first RC helicopters have been powered by combustion engines ([[Glow fuel]], or [[Nitromethane|nitro]], as well as gas, or gasoline as the fuel source).  Original helicopter "classes" were based on the engine size. For example, a helicopter with a {{convert|0.30|cuin|abbr=on}} engine was a ''30 class'' and a helicopter with a {{convert|0.90|cuin|abbr=on}} engine was referred to as a ''90 class'' helicopter.  The bigger and more powerful the engine, the larger the main rotor blade that it can turn and hence the bigger the aircraft overall. Typical flight time for nitro helicopters is 7–15 minutes depending on the engine size and tuning.

=== Electric ===

[[Image:TDR-Yellow2.JPG|right|thumb|The 252 km/h fast electric helicopter TDR]]

Two small electric helicopters emerged in the mid-1990s. These were the Kalt Whisper and the Kyosho EP Concept, flying on 7–8 × 1.2&nbsp;Ah NiCad batteries with brushed motors. However, the 540-sized brushed-motors were on the limit of current draw, often 20–25 [[Electric current|amps]] on the more powerful motors, hence brush and commutator problems were common.

Recent advancements in battery technology are making electric flying more feasible in terms of flying time. [[Lithium polymer]] (LiPo) batteries are able to provide the high current required for high performance aerobatics while still remaining very light. Typical flight times are 4–12 minutes depending on the flying style and battery capacity.

In the past electric helicopters were used mainly indoors due to the small size and lack of fumes. Larger electric helicopters suitable for outdoor flight and advanced aerobatics have become a reality over the last few years and have become very popular. Their quietness has made them very popular for flying sites close to residential areas and in places such as [[Germany]] where there are strict noise restrictions. Nitro helicopters have also been converted to electric power by commercial and homemade kits.

{{anchor|Picooz Extreme MX-1}}The smallest remote-controlled production model helicopter made (Guinness World Records 2014) is the Silverlit Nano Falcon XS sold at many toy stores (although this is infrared controlled, not radio), electronics stores and internet stores, costing about $30 (£28). The next smallest is the Nano Falcon, which previously held the record for the smallest rc helicopter.

Several models are in contention for the title of the smallest non-production remote-controlled helicopter, including the [[Pixelito]] family of micro helicopters, the [[Proxflyer]] family, and the [[Micro flying robot]].

===Coaxial===
[[Image:LamaV3Coax.jpg|thumb|right|A [[Lama v4|Lama V3]] model helicopter, with a simplified coaxial rotor system.]]
A recent innovation is that of [[coaxial rotors|coaxial]] electric helicopters. The system's simple direction control and freedom from torque induced yaw have, in recent years, made it a good candidate on small models for beginner and/or indoor use. Models of this type, as in the case of a full-scale helicopter, eliminate rotational torque and can have extremely quick control response, both of which are very pronounced in a [[cyclic/collective pitch mixing|CCPM]] model.  Most cheaper models do not have a swashplate, but instead use a third rotor on the tail to provide pitch control. These helicopters have no roll control and have limited mobility.

While a coaxial model is very stable and can be flown indoors even in tight quarters, such a helicopter has limited forward speed, especially outdoors.  Most models are fixed-pitch, i.e. the [[collective pitch]] of the blades cannot be controlled, plus the cyclic control is only applied to the lower rotor.  Compensating for even the slightest breeze causes the model to climb rather than to fly forward even with full application of [[Helicopter pilotage#Cyclic|cyclic]]. More advanced coaxial constructions with two swash plates and/or pitch control (common for full-scale [[Coaxial rotors|coaxial helicopters]] like [[Kamov]]s) have been realized as models in individual projects but have not seen the mass market {{As of|2014|lc=y}}.

===Multirotor model helicopters===
[[File:The Hexacopter.jpg|thumb|Hexacopter.<ref>{{cite news|title=ALMA Filmed with Hexacopter|url=http://www.eso.org/public/announcements/ann13067/|access-date=6 September 2013|newspaper=ESO Announcement}}</ref>]]
{{see also|Quadcopter}}
More recently, [[multirotor]] designs have become popular in both the RC hobby and [[unmanned aerial vehicle]] (UAV) research.  These vehicles use an electronic [[control system]] and electronic [[sensor]]s to stabilize the aircraft. Multirotors are generally more affordable, easier to construct, and simpler to operate than RC helicopters. This made multirotor aircraft an appealing platform for amateur model aircraft projects and aerial photography.<ref>{{cite web|url=http://makezine.com/2010/01/13/how-to-quadrocopter-based-on-arduin/|title=How-To: Quadrocopter based on Arduino - Make|date=13 January 2010}}</ref><ref>{{cite web|url=http://ng.uavp.ch/moin/FrontPage|title=FrontPage - UAVP-NG - The Open Source Next Generation Multicopter}}</ref>

===Size classes===
Nitro RC helicopters are categorised under the following classes:
* 30 size : Engine 0.3 cubic inch, Main Blades 550-600mm
* 50 size : Engine 0.5 cubic inch, Main Blades 600-620mm
* 60 size : Engine 0.6 cubic inch
* 90 size : Engine 0.9 cubic inch, Main Blades 690-710mm

Modern RC helicopters are generally classed by the length of the main blades (with few exceptions). Common classes are:
* Micro (under 200mm main blades)
* Mini (240-420mm blades) - classically called 300–450.
* 500 (425-500mm)
* 600 (600mm)
* 700 (standard competition size)
* 800

==Radio gear==
{{more citations needed section|date=October 2014}}

===Transmitter===
RC helicopters generally require between 3 and 7 channels for control (although micro helicopters that utilize a 2-channel infrared control system also exist). Small fixed-pitch helicopters use a 4-channel radio ([[throttle]], [[Elevator (aircraft)|elevator]], [[aileron]], [[rudder]]); while collective-pitch models need a minimum of 5 channels ([[throttle]], [[collective pitch]], [[Elevator (aircraft)|elevator]], [[aileron]], and [[rudder]]). 6th channel is often used for gyro gain. 7th channel commonly used for engine governor control for fuel powered models.  Because of the normal interaction of the various control mechanisms, advanced radios include adjustable mixing functions, such as throttle/collective and throttle/rudder.<ref>{{cite web | url=http://www.pilotmart.net/best-rc-helicopter/ | title=Difference Between 3,4, and 7 Channel Controllers | access-date=23 January 2015}}</ref> Radio prices vary from $50–$3,000 USD.

Early radio controls systems used [[amplitude modulation]] (AM) to transmit their signals.  In the late '70s, [[frequency modulation]] (FM) became more commonplace.

===Spread spectrum===
[[File:Spektrumdx6i.jpg|thumb|right|[[Spektrum RC|Spektrum]] DX6i 6-channel spread spectrum computerized aircraft radio which may be used for both helicopters and fixed-wing models]]

Starting with the Spektrum DX6 park flyer transmitter system in 2006, RC flying began the departure from various lower frequencies which were subject to interference and were less reliable than the new spread spectrum protocols. Systems such as Spektrum and JR use the DSM2 and later, DSMX [[direct-sequence spread spectrum]] (DSSS) method, where they transmit on a pair of fixed channels chosen when the radio and receiver are turned on. Any subsequent systems would avoid using these channels and continue searching for another unused pair of channels.

Systems such as [[frequency-hopping spread spectrum]] (FHSS) used by [[Futaba Corporation|Futaba]] employ frequency hopping on the 2.4&nbsp;GHz band instead of the various frequencies in the lower MHz ranges. The advantage is that radios are no longer using a fixed frequency during flight, mitigating the risk of interference on that fixed frequency.

With either method many radios can be transmitting at once without interfering with each other. The Futaba systems change frequency approximately every two milliseconds, so even if two transmitters are using the same channel they are not doing so for long. The pilot will not notice any abnormal behavior of the model in the 1/500th of a second that they are interfering. This gives one the advantage of turning on a transmitter without regard to channels currently in use by other pilots' radios.

One downside to 2.4&nbsp;GHz is that precautions must be taken during installation since certain materials such as carbon fiber can mask the signal. In some cases, satellite receivers with secondary antennas need to be used to maintain better line-of-sight with the [[transmitter]] radio. Another drawback is that a 2.4&nbsp;GHz standard has yet to evolve so that receivers and transmitters can be mixed regardless of their respective manufacturer.

===Controls===
Learning to fly a collective pitch RC helicopter takes time and practice. Many modelers join a club so they can be instructed by experienced RC pilots, or follow on-line guides.<ref>{{cite web | url=http://www.rchelicopterfun.com/are-rc-helicopters-hard-to-fly.html | title=Are RC helicopters hard to fly? | access-date=28 October 2014}}</ref>

RC Helicopters usually have at least four controls: roll - cyclic pitch, elevator (fore-aft cyclic pitch), rudder (yaw) and pitch/throttle (collective pitch/power).<ref name="Controls" /> For simple flight, the radio is usually configured such that pitch is around −1 degree at 0% throttle stick, and somewhere around 10 degrees at 100% throttle stick. It is also necessary to modulate the throttle in conjunction with the pitch so that the model maintains a constant rotor speed. This is beneficial for consistent and smooth flight performance.

If aerobatic '3D' performance is desired, then automatic throttle, or ''idle up'', mode of flight is used. In this mode, the collective pitch ranges from its negative limit at 0% throttle stick input, up to its positive limit at 100% throttle stick. The throttle, on the other hand, is modulated automatically to maintain a constant rotor speed and is usually at its lowest value when the throttle stick is centered and the pitch is 0. This mode allows the rotor to produce a thrust upwards (by using negative pitch) which, when the model is inverted, allows sustained inverted flight. Usually a more advanced computer radio is used for this kind of flying, which allows customization of the throttle-collective mix.

The cyclic and yaw controls are not by definition different in these two modes, though 3D pilots may configure their models to be much more responsive.

==Construction==
[[File:RC Helicopter Bell222 with Pilot.png|thumb|Radio controlled model of a [[Bell 222]] helicopter with pilot.]]
Construction is typically of plastic, glass-reinforced plastic, aluminium or carbon fiber.  Rotor blades are typically made of wood, fiberglass or carbon fiber.  Models are typically purchased in kit form from one of about a dozen popular manufacturers and take 5 to 20 hours to completely assemble.

These model helicopters contain many moving parts analogous to those on full-size helicopters, from the [[Swashplate (helicopter)|swashplate]] to [[Helicopter rotor|rotor]] and everything in between.

The construction of helicopters has to be more precise than for fixed-wing model aircraft, because helicopters are susceptible to even the smallest of vibrations, which can cause problems when the helicopter is in flight.

Additionally, the small size and low weight of R/C helicopters and their components means that control inputs, especially cyclic (pitch and roll) can have a very fast response, and cause a rotation rate much faster than the equivalent input might produce on a full-size aircraft. This quick response can make the model unnecessarily difficult to fly. For this reason, most model helicopters either have a [[Helicopter rotor#Stabilizer bar|flybar]] or electronic stabilizing equipment.

To reduce mechanical complexity and increase precision of the control of the [[swashplate]] some model helicopters use [[cyclic/collective pitch mixing]].

==Competition==
Aerobatic helicopter flying has historically followed the [[Fédération Aéronautique Internationale]] rules, which for helicopters are labelled F3C.  These include a predetermined routine of hovering and aerobatics.

An advanced form of RC helicopter flying is called 3D. During [[3D flying]], helicopters perform advanced [[aerobatics]], sometimes in a freestyle form, or in a predetermined set of moves drawn up by the organisers of the competition. There are a number of 3D competitions around the world, two of the best-known being the [[3D Masters]] in the [[United Kingdom|UK]] and the eXtreme Flight Championship (XFC) in the United States.

In 2008, the [[Fédération Aéronautique Internationale]] introduced the class of F3N as a provisional class for international 3D competition and in 2010 at the CIAM Plenary meeting, F3N gained formal approval for competition effective 1 January 2011.

F3N rules are designed to provide a consistent standard of judging throughout the World and give countries the chance to field a Team at a World championship hosted every two years. F3N is conducted in a similar manner as 3D Masters and 3DX with 3 round types made up of Set Manoeuvres, Freestyle Flight and Flight to Music.

==Commercial applications==
{{Globalize |section |discuss=Talk:Radio-controlled helicopter#Globalize | date=December 2014}}
While some companies make use of RC multicopters for low altitude [[aerial photography]], filming, policing, and remote observation or inspection, RC helicopters are not commonly used for commercial purposes. One notable exception is crop spraying with large RC helicopters such as the [[Yamaha R-MAX]].

US [[Federal Aviation Administration]] regulations  from 2006 grounding all commercial RC model and [[unmanned aerial vehicle]] (UAV) flights have been upgraded to require formal FAA certification before being permitted to fly at any altitude in the United States.<ref name=no-flight>{{cite web|url=http://photographyforrealestate.net/2012/01/24/warning-faa-says-us-airspace-is-closed-to-all-commercial/ |title=Warning: FAA Says US Airspace Is Closed To ALL Commercial |publisher=Photography For Real Estate |date=2012-01-24 |access-date=2013-12-05}}</ref> All commercial owners must register with FAA, as well as pass a knowledge test.  Non-commercial operators must register only if the models they fly weigh more than 0.55 pounds (250g).

==Controlling methods ==

===Radio control===

Most RC helicopters make use of a handheld transmitter with an antenna that sends signals to the helicopter's receiver, usually a radio frequency of 27&nbsp;MHz, 49&nbsp;MHz, or 2.4&nbsp;GHz.<ref>{{cite web |last1=James |first1=Michael |title=Frequencies for RC Cars |url=https://www.liveabout.com/radio-frequencies-in-the-us-for-radio-controlled-vehicles-2862530 |website=LiveAbout |access-date=25 August 2022 |language=en}}</ref> Infrared radios are also used by some models. Infrared radios have the disadvantage of potentially being interfered by sunlight or fluorescent lights,<ref>{{cite web |title=How Remote Controls Work |url=https://electronics.howstuffworks.com/remote-control2.htm |website=HowStuffWorks |access-date=25 August 2022 |language=en-us |date=10 November 2005}}</ref> making them more suited for indoor RC helicopters.

Radio controls generally have two sticks used to control the movement of the helicopter. On a 4-channel transmitter, there are four different modes in which the control sticks can be set:<ref>{{cite web |title=RC Helicopter Transmitter Modes |url=https://www.rc-airplane-world.com/rc-helicopter-transmitter-modes.html |website=www.rc-airplane-world.com |access-date=25 August 2022 |language=en}}</ref>

* Mode 1 – the left stick controls pitch and yaw movements, while the right stick controls throttle and roll movements.
* Mode 2 – the left stick controls throttle and yaw movements, while the right stick controls pitch and roll movements.
* Mode 3 – the left stick controls pitch and roll movements, while the right stick controls throttle and yaw movements.
* Mode 4 – the left stick controls throttle and roll movements, while the right stick controls pitch and yaw movements.

Transmitters may include trims for each axis to correct any undesired movement of the helicopter.

Some radio transmitters include a charging cable to charge the helicopter's battery using the transmitter's own batteries.

===Phone and tablet control===

Some RC Helicopters can be controlled from a [[smartphone]] or [[Tablet computer|tablet]]. Controls are usually via a downloaded application from the helicopter's manufacturer, and often resemble physical stick controls on a transmitter, or utilize the [[Accelerometer#Consumer electronics|accelerometer]] built into the mobile device.

Infrared controlled helicopters can be controlled with an [[IR blaster]] connected to the [[3.5 mm audio jack]] interface on a mobile device.<ref>{{cite web |title=Air Hogs - The Leader in Remote Control Vehicles |url=http://airhogs.com/en/products/heli-replay |archive-url=https://web.archive.org/web/20130115091753/http://airhogs.com/en/products/heli-replay |archive-date=2013-01-15  |date=15 January 2013}}</ref>

Another communications method used is [[Wi-Fi]]. The helicopter's built in computer creates its own [[wireless network]], which the Wi-Fi enabled mobile device connects to and communicates with the helicopter.<ref>{{cite web |title=50600 WiFli Helicopter User Manual INS-50600-FCC.ai Interactive Toy Concepts |url=https://fccid.io/QE850600/User-Manual/Users-Manual-1486354 |website=FCC ID |access-date=25 August 2022 |language=en}}</ref>

==Safety ==
'Model' helicopters can be dangerous. Safety precautions, proper maintenance, and an understanding of the mechanics and flight characteristics of the models are necessary to prevent accidents.<ref name=some-safety-guidelines>{{cite web |author=C.Hatch |title=Safety Precautions With Remote Control Toys |url=http://whiztoy.com/articles/play-safe-with-rc-toys/ |publisher=WhizToy |date=2013-10-13 |access-date=2013-12-07 |url-status=dead |archive-url=https://web.archive.org/web/20131109074153/http://whiztoy.com/articles/play-safe-with-rc-toys/ |archive-date=2013-11-09 }}</ref> Modelers who fly at sanctioned sites are required to follow safety rules designated by national model aircraft organizations. In the United States, the [[Academy of Model Aeronautics]] (AMA) publishes and updates safety rules for all model aircraft operations, including fixed and rotary wing models.<ref name="AMA Safety">{{cite web | url=http://www.modelaircraft.org/files/105.pdf | title=Academy of Model Aeronautics National Model Airc raft Safety Code | publisher=Academy of Model Aeronautics | access-date=27 October 2014}}</ref> In 2014, several organizations with interest in unmanned aircraft systems in partnership with the [[Federal Aviation Administration]] launched a new educational campaign to promote safe and responsible flying and provide guidance for hobbyists and commercial users.<ref>{{cite web | url=http://www.knowbeforeyoufly.org/ | title=Know Before You Fly | date=2014 | access-date=23 December 2014}}</ref>

=== Deaths ===
In July 2013, a 41-year-old Swiss man was found dead in [[Mauensee]] near his model helicopter. He had "severe head and arm injuries".<ref name =swiss-fatality>{{cite web|author=Everett Balmores |url = http://www.rcheliresource.com/tragic-news-from-switzerland-involving-a-model-helicopter/ |title=Tragic news from Switzerland involving a model helicopter |publisher=RC Heli Resource |date=2013-07-11 |access-date=2013-12-05}}</ref>

A September 2013 incident in [[New York City]] highlighted the possible dangers of remote controlled model helicopters when a 19-year-old enthusiast, who was very experienced in flying remote controlled helicopters, died after one of his helicopter's blades struck his head.<ref name=ny-fatality>{{cite news| author=J. David Goodman| title=Remote-Controlled Model Helicopter Fatally Strikes Its Operator | url=https://www.nytimes.com/2013/09/06/nyregion/remote-controlled-copter-fatally-strikes-pilot-at-park.html?_r=0 |work=New York Times| date=September 5, 2013|access-date=2013-12-05}}</ref>

==Miniature helicopters==
Miniature helicopters are remotely controlled helicopters with a weight ranging from just a few grams to one hundred grams. Most in production are toys aimed at hobbyists and enthusiasts. In addition, there are many companies making prototypes for military and security applications. Miniature helicopters are popular demonstrations for the latest technologies in [[miniaturization]].<ref name="miniaturization">{{cite web|url=http://www.epson.co.jp/e/newsroom/news_2004_08_18.htm |title=Epson Corporate: Newsroom |publisher=Epson.co.jp |access-date=2013-12-05}}</ref>

Examples of these types of miniaturized models are the E-Flite Blade CX and CX2 and the [[Picoo Z]], a popular consumer model. Along with the [[Proxflyer]], a prototype and basis for many production models. One final example is a one-off prototype and technology demonstration item that was developed by [[Seiko Epson]], and demonstrated at the [[International Robot Exhibition]] in Tokyo is the [[Seiko Epson Micro flying robot]].

==See also==
*[[Radio-controlled aerobatics]]
*[[Radio-controlled model]]
*[[IRCHA]]

==References==
{{reflist}}

{{Commons category|Radio-controlled model helicopters}}

{{Radio-controlled models}}
{{Helicopters}}

{{DEFAULTSORT:Radio-Controlled Helicopter}}
[[Category:Radio-controlled helicopters| ]]