Fullscreen HTML5Med Res (??MB)HTML4

Ever since the legend of Icarus man has dreamed of being able to fly. Man has since flown in various ways, such as kites that could carry men in China in the 5th century, hot air balloons in France in 1783 and we have been flying in heavier-than-air machines for more than a century. But the ultimate dream is to fly with the smallest possible machine that can lift a human into the air. In this article we look at machines which can – or at least perhaps have the potential to – do this. Personal Flight Vehicles by Dr David Maddison P ersonal flight vehicles are defined as being designed to lift one or two people with flight equipment on their backs or standing or sitting on such equipment but not in an enclosure such as an aircraft cockpit. Such vehicles are mostly VTOL; vertical take off and landing, based on jet engines, rocket packs or ducted fan systems. Early work on rocket packs was done in the late 50s and early 60s for the US military and the space program where it was thought that they could transport astronauts over the lunar surface. Personal flight vehicles require very high power to weight ratios and thus very powerful motors. Hydrogen peroxide, ducted fans with reciprocating or rotary engines, turbojet and turbofan motors have all been used successfully. A hydrogen peroxide motor is simple in principle and uses “high test” hydrogen peroxide (85 to 98% H2O2), in 16  Silicon Chip contrast to medicinal hydrogen peroxide bought at the chemist which is 3%, or food grade which is 30%. When the hydrogen peroxide fuel is bought into contact    with a catalyst such as silver, it violently decomposes into steam and oxygen and expands by 5000 times. The resulting gas is directed through nozzles that generate thrust.    In one particular application of a personal flight system, which we will discuss later, hydrogen peroxide motors were used at the tips of a helicopter rotor in order to cause it to rotate. There are many YouTube videos and websites concerned with experimenters making their own high test peroxide fuels (since they are almost unavailable as only a few specialist companies make the fuel). Be warned: concentrated hydrogen peroxide is an extremely hazardous substance and should only be ex- siliconchip.com.au In ancient Greek mythology, Icarus dared to fly too close to the Sun, which melted the wax holding his wings in place. One of mankind’s first dreams of a personal flight system. perimented with if you know what you are doing. potential disadvantage is that they are larger than a turboDucted fan propulsion systems involve a “fan” or propel- jet that creates the same thrust. ler mounted in a duct or shroud. Typically the fan has more blades and is of smaller diameter than an unducted rotor. Personal Flying Systems from the past The smaller diameter fan can spin at a much higher rate The Hiller Flying platform was developed in the 1950s by than an unshrouded propeller because of the limit set by Hiller Aircraft as part of a US Army and US Navy program the tip speed which must be less than the speed of sound to develop a flying platform that could be flown with minisince performance drops dramatically when the tip speed mal training by the user. It utilised contra-rotating ducted approaches that limit. fans powered by two Nelson H-56 30kW piston engines. So ducted fans have the advantage of compact size, The pilot controlled it by simply leaning in the direction relatively low noise, high efficiency at he wanted to go. Several variants of low speeds and high thrust, the ability the model were made and 1031-A-1 (with appropriate mounting) of thrust model was first flown in 1957 (see vectoring and safety, as the shroud photos overleaf). protects people and objects from comIt weighed 168kg empty and could ing into contact with the fan. Typical carry an 84kg payload (pilot plus ducted fans are powered by a reciprofuel), with a top speed of 26km/h and cating engine. maximum service height of 10m. Its A turbojet is a jet engine in which flight time duration is not known. incoming air is compressed by comThe aircraft was quite stable and pressor blades after which it enters could not tumble. If the pilot leaned a combustion chamber, where fuel is over too far, the aircraft would tend added and burned, causing the producto return to the vertical. tion of hot, high pressure gas. This gas A video of the flying platform can then enters the turbine and expands, be seen at “Hiller Flying Platform” causing it to rotate and drive the comhttps://youtu.be/W3FS3D1rCos pressor blades. After the turbine, the The Pin-wheel helicopter gas enters the tapering exhaust or “propelling nozzle” in which gas velocity is The Pin-wheel helicopter was built Operation of a hydrogen peroxide increased while pressure is decreased as part of a US military contract in rocket motor as used in all existing (according to the Venturi effect). The rocket packs. 1) Compressed nitrogen at 1954 and was powered by hydrogen 4MPa or 580psi. 2) high test hydrogen high speed exhaust generates thrust peroxide rocket motors at the tips of peroxide 3) regulator valve 4) catalyst. which propels the engine. the rotor blades. It was invented by A turbofan is a variation of the turbo- The compressed nitrogen forces peroxide Gilbert W. Magill and was intended through the regulator valve which is jet engine which has large fan blades at to be folded up and stored in a small controlled by the pilot and then into the front of the engine that exceed the container. Since the rotor blades were contact with the catalyst which causes diameter of the gas turbine at the core propelled at their tips, there was no the decomposition of the hydrogen of the engine. The large fan causes a torque reaction to overcome and peroxide and a volume expansion of proportion of air to bypass the engine therefore no tail rotor was necessary. 5000 times after which it is ejected at core and the bypass air provides a pro- supersonic speed via the exhaust nozzles It had surprisingly good perforto create thrust. portion of the thrust. mance, with a top speed of over Source: Dart evader derivative work: Turbofan engines are more efficient 160km/h, a ceiling of around 15000 Malyszkz (Rocket_Belt_Propulsion. than turbojet engines and are widely feet and a range of 32km on 20 litres PNG), Creative Commons license. used on commercial jet aircraft. One of 90% hydrogen peroxide fuel. siliconchip.com.au August 2016  17 These two diagrams show the difference between the turbojet engine (above) and the turbofan engine (right). Image source: (above) Jeff Dahl; (right) K Aainsqatsi – both Creative Commons licence. You can read more about this project, from before this aircraft first flew, in Flying magazine of February 1952 at https://books.google.com.au/books?id=3XUK_52VvmYC Also see Popular Science of January 1952 https://books. google.com.au/books?id=ryEDAAAAMBAJ&pg=PA89 A video of this device flying can be seen at “One-Man Helicopter (1957)” https://youtu.be/GpPHT2UvplA The Bell Rocket Belt The Bell Rocket Belt is perhaps the most well known of all personal flight systems, having been used in TV serials such as Lost in Space and the James Bond movie Thunderball as well as in numerous public displays such as the opening of the 1984 Los Angeles Olympics. The Bell Rocket Belt started to be developed in the mid 1950s for the US Army and was demonstrated to the Army in 1961 although they were not impressed with the short flight time of 21 seconds. It too used a hydrogen peroxide propulsion system. Control is conducted by moving the rocket nozzles and also tilting the entire pack to fly sideThe Hiller Model 1031-A-1 Flying Platform showing a soldier using it as a shooting platform. 18  Silicon Chip ways as well as the pilot moving their body. As the pilot will fall out of the sky when the fuel runs out at 21 seconds, it is vitally important to know when to land. There is a timer that beeps every second until the 15 second mark is reached and then sounds continuously telling the pilot to land. The thrust developed was 136kg and it could fly at up to 55km/h. The rocket belt weighed 57kg and it carried 19 litres of fuel. Wendell Moore was the inventor and today all existing rocket packs are based on his design. An attempt by some entrepreneurs to build an improved version of this rocket belt in 1992, called the RB2000, using more modern lightweight alloys and other materials resulted in a pack that had only slightly better performance than the original with a flight duration of 30 seconds and a fuel capacity of 23 litres. Bell Pogo One version of the Bell Pogo was like a two-person version of the Bell Rocket Belt. NASA had an interest in it The Hiller Flying Platform, as it can be seen today at the Steven F. UdvarHazy Center in Chantilly, Virginia, USA, a part of the Smithsonian Air and Space Museum. siliconchip.com.au Bell No.2 Rocket Belt at the Udvar-Hazy Center of the Smithsonian National Air and Space Museum in Chantilly, Virginia, USA. The centre tank contains pressurised nitrogen which forces the hydrogen peroxide in the side tanks into the catalyst structure on top where it rapidly decomposes into steam and oxygen, whereupon it expands in volume by 5000 times and is ejected out of the nozzles on the side. US Patent 3021095, filed by inventor Wendell Moore for Bell Aerospace Corporation in 1960, entitled “Propulsion unit”. as a lunar exploration vehicle and the US Army had an interest in it as a vehicle to cross ravines. NASA decided the risk of a crash was too high and the Army decided it was too complicated to use without a lot of training. The other version of the POGO was designed for one person. For a video of both the one and two person Bell POGOs in operation see http://videos.howstuffworks.com/ discovery/33674-strange-planes-the-bell-pogo-video.htm de Lackner HZ-1 Aerocycle Flying Platform The de Lackner Aerocycle was designed as a one man reconnaissance platform for the US Army. The designer, Charles Zimmerman, proposed a platform beneath which Two-man Bell POGO. siliconchip.com.au helicopter-like rotors were mounted. Control was to be effected by the pilot shifting their body weight, so-called kinesthetic control. The aircraft first flew on the 22nd November 1954 and 12 were built for the US Army and 160 test flights were conducted. It had an empty weight of 78kg, a maximum weight of 206kg and a fuel capacity of 3.8 litres. It was powered by one Mercury 20H 30kW marine engine and had a maximum speed of 121km/h and cruise speed of 89km/h. Its range was 24km and maximum flight time was 45 minutes with a service ceiling of 5000 feet. It was intended to carry up to 54kg of cargo or an extra The de Lackner HZ-1 Aerocycle was available in both land-based and (as seen here) amphibious versions. August 2016  19 Actor Sean Connery (as James Bond) shown with a Bell Rocket Belt, as used in the movie “Thunderball”. (Professional Rocket Belt pilots actually flew them!) One was also used in the 1960s “Lost in Space” TV series as well as at the 1984 Los Angeles Olympic Games opening ceremony. The Bell Jet Flying Belt, the world’s first jetengine powered jet pack. 19l fuel tank to extend its range from 24km to 80km. The aircraft was meant to be easy to fly and non-pilots were meant to be able to operate it with only 20 minutes of instruction but it was soon determined that it was not easy to fly and only a trained pilot could operate it. Two accidents were caused by the 4.6m diameter counter rotating blades striking and disintegrating. The conditions under which the blades would strike each other were never able to be determined and these crashes and the fact that only trained pilots could fly it caused the cessation of the program. A video of the Aerocycle flying can be seem at “OneMan Amphibious ‘Copter” https://youtu.be/1oYS_5SgU_0 Bell Jet Flying Belt The world’s first jet pack was the Bell Aerosystems Jet Flying Belt, built for the US Military. It was designed to overcome the limitations of the hydrogen peroxide fuelled Bell Rocket Belt with its sub-30 second flight times. A new miniature jet engine, called the WR19 inside the company (F107 outside the company), needed to be developed for this project by Williams Research Corporation (now known as Williams International) as there were no small jet engines available at the time. This engine was later used in cruise missiles such as the Tomahawk. As used in the Flying Belt, it weighed 27kg and produced 195kg of thrust while consuming about 136kg of Jet-A fuel per hour. The flight time was about 20 to 25 minutes at speeds of up to 135km/h. The engine was classified as a military secret at the time and never used in non-military aircraft. Its performance was such that it 20  Silicon Chip produced the same power as small civilian aircraft at the time (1965) but at one twentieth of the size. Even today, the power to weight ratio of this engine is hard to match. The engine was mounted vertically on the Flying Belt, with the air inlet at the bottom and the exhaust at the top and then into nozzles on either side. These could be tilted forwards, backwards or sideways by the pilot to control motion, just like in the Bell Rocket Belt. The Jet Belt first flew on 7th April 1969 but on 29th May 1969, Wendell Moore, who invented this and the Rocket Belt, died at age 51 and work on the project stopped forever. Who knows where this work would have gone if he had not prematurely passed away? With Wendell Moore’s death, the project eventually did not have the support of the military as the weight of the device was too great, making landings hazardous for the pilot and the maintenance requirements of the engine were too much, not to mention the hazard to the pilot of an uncontained turbine blade failure. At this time, helicopters had also developed into very effective military air vehicles for transporting soldiers. A video of the operation of this device can be see at: “Jet engine Jet pack : World’s first Gas-Turbine backpack. The Bell WR19 Jetbelt” https://youtu.be/DpJxzswUDD0 Williams X-Jet The Williams X-Jet was in a way a development of the Bell Flying Belt. Engineers tried to work out how to extend the flying time beyond the 20-25 minutes of the Flying Belt. This required carrying more fuel. They were inspired by the Hiller flying platform (see above) which the pilot stood on. Such a platform would enable the carrying of more fuel than could be carried on the pilot’s back. The X-Jet had a modified Williams F107 engine with 258kg thrust, somewhat more than the same engine used in the Flying Belt. The X-Jet’s empty weight was 182kg and fully loaded it was 250kg. It had a maximum speed of 96km/h, a service ceiling of 10,000 feet and endurance of 30-45 minutes, around twice as long as the Jet Belt. Flight control was by leaning in the direction of desired travel and by thrust control. It worked successfully and was demonstrated to the US Army in the 1980s but no suitable military application could be found that could not be siliconchip.com.au Mythbusters’ Attempt to Build a Jet Pack The Williams X-Jet, nicknamed “the flying pulpit”. achieved with helicopters. Videos of the Williams X-Jet can be seen as follows: “The WASP (Williams Aerial Systems Platform)” https:// youtu.be/XJARrc40imk This video is a video of a display screen at the Boeing Museum of Flight in Seattle, Washington, USA: “WILLIAMS X-JET” https://youtu.be/wLsqyphVERA Also see “Your Personal Flying Machine X Jet WASP!!” https://youtu.be/27HaGvHzbgQ Coaxial Helicopter The Gyrodyne XRON model was a small helicopter built in the USA in 1960. It was powered by a tiny 41kW Solar Turbines model YT-62-S turboshaft engine running on kerosene. This aircraft was originally developed for the US Navy and later the US Marine Corps. One use envisaged was to drop this aircraft to an airman downed behind enemy lines to facilitate their escape. It was also developed into an unmanned drone. It won the “most manoeuvrable helicopter” prize at the Paris Air Show in 1961. For a silent video of military qualification trials of this aircraft see “Gyrodyne disposable XRON military qualification flight auto-rotation” https://youtu.be/ogIS_VbORbc There are also other videos of different variants of this aircraft. In series 3 episode 8 of Mythbusters, they set about building a jet pack with plans obtained off the internet. They have an extremely well equipped workshop and are highly experienced and capable machine builders but they could not get the device made from these plans to fly. Of course, as shown in this article, jet packs or personal flight vehicles as we refer to them are possible but all the devices that work have taken very large amounts of money, time and resources to get to a flying state. The episode of Mythbusters where they try to build the device can be viewed at “Mythbusters S03E08 Jet Pack” https://youtu. be/h8zIfkMp08U Myth: BUSTED! Gluhareff Helicopters MEG-1X and MEG-2X In 1952 Eugene Gluhareff created a company to build “backpack” helicopters powered by his pressure jet engine. The MEG-1X of circa 1957 weighed less than 31kg and had a single rotor blade with a tip-mounted pressure jet motor and counterweight. Maximum take-off weight was 104kg and maximum speed was 88km/h with a hover ceiling of 4900 feet. Flight endurance was 14-18 minutes. The US Air force was impressed with the MEG-1X and asked Gluhareff to build another model, the MEG-2X, which had two blades and also a MEG-3X. These aircraft were not commercially produced and were perhaps the smallest helicopters ever built. It is understood that they only made tethered flights. The pressure jet engine is extremely simple with no moving parts and is somewhat a akin to a pulse jet engine. Said to be “sonically tuned”, it relies on precise control of sound waves in the combustion chamber. For further information see https://en.wikipedia.org/wiki/Gluhareff_Pressure_Jet Kits are available to build a pressure jet engine. For a video of this aircraft see “One man Backpack helicopter Powered by G8-2 Pressure Jet Engine invented by Eugene Gluhareff 1956” https://youtu.be/s0DY4Qe14A4 Trek Aerospace EFV-4A An Australian registered Gyrodyne XRON one man, turboshaft-powered open cockpit helicopter. siliconchip.com.au The Trek Aerospace Exoskeleton Flying Vehicle (EFV) was first tested in 2003 and has a unique design with two counter-rotating 1-metre overhead ducted fans driven by an 88kW rotary motor. August 2016  21 Gluhareff MEG-1X backpack helicopter in a tethered flight test. The Trek Aerospace EFV-4A. The aircraft is controlled via a fly-by-wire system and each duct can be tilted individually. It has a top speed of 180km/h and range of 295km with a 46 litre tank. Its dry weight is 170kg and its maximum payload is 162kg. Maximum take off weight fully fuelled is 378kg. Development of this vehicle and others based upon it seems to have ceased and Trek Aerospace now provides services related to ducted fan technology. A video of the EFV in operation can be seen at “Trek Exoskeleton Flying Vehicle, Personal JetPack” https://youtu. be/KUs8riw9Afo Personal flight vehicles under development We will now look at some personal flight vehicles that are currently in existence or under development, such as the Jetpack Aviation JB-9 and JB-10. Jetpack Aviation is a company run by Australian entrepreneur David Mayman and American Bill Suitor, based in California. They have recently developed and flown the JB-9 JetPack, which it and its predecessors have been under development for over 40 years. The JB-9 uses turbojet engines chosen for their compact size and lighter weight in comparison with turbofan engines, even though they have higher fuel consumption and higher exhaust temperatures. Battery technology is important with a jet engine pack as the current drain during engine start up can be up to 50A and ongoing current is up to 15A. The JB-9 carries about 38 litres of kerosene which is burned at the rate of about 3.8 litres per minute for around a ten-minute flight time, with an electronically limited speed of 100km/h. A JB-10 model with a top speed of 200km/h is under development On 3rd November 2015 Jetpack Aviation flew the JB-9 around the Statue of Liberty in New York (see video). Under further development are auto-stability systems and a parachute system that will automatically deploy. The developers are discussing the possibility of JetPack racing as a competitive sport. Also under development are improvements to engines and engine management systems, a four engine version and a flight simulator for training. Longer 22  Silicon Chip term plans include a fully stabilised version and the possibility of turbofan engines instead of turbojets. Videos to watch: “JetPack Aviation JB-9 JETPACK” https:// youtu.be/f3AwBSwFV2I; “JB-9 JetPack Flight (Jet engine audio)” https://youtu.be/QhnXxJs0GpE The Martin Jetpack The Martin Aircraft Company of New Zealand is developing a personal “Jetpack” that seems to have every possibility of becoming the world’s first mass-produced system and it is under final test right now. Note that even though it is called a “Jetpack” it is powered by two ducted fans. The Jetpack is not wearable like, for example, the Jetpack Aviation machine but has its own landing skids and the pilot stands within the machine. It uses a custom-designed 1.2-litre 2-stroke V4 156kW engine weighing 48kg. Standard automotive gasoline is used, in a 45-litre tank. Flight duration is 30 minutes and the cruise speed is 30 knots or 56km/h. It uses “fly by wire” with no direct connection between the control surfaces and pilot stick. It has a range of 30-50km, depending upon environmental conditions, with an operational ceiling of 3000 feet. Its weight is 200kg empty. Flying the Jetpack Aviation JB-9. siliconchip.com.au The Martin Jetpack is designed for ease of flight; if the pilot lets go of the controls it will simply hover in place. View of the Martin Jetpack from above showing arrangement of the ducted fans. Naturally, with an aircraft of this nature if there is an engine failure it will simply fall out of the sky, so it incorporates a ballistic parachute to arrest any fall, even from a very low altitude of six metres (see test of parachute in first video). Deliveries are expected to start in the second half of 2016. Its initial applications will be for police, fire services, defence and emergency response organisations but it also has potential uses in the recreational market and in its unmanned remote control version, can deliver payloads of up to 120kg, unlike a quadcopter which might be restricted to a few kilograms. It is capable of operating in a “mule train” mode in which one unit is piloted and up to five other unmanned units are electronically linked to the first one, to follow it and land. The Martin Jetpack was Time magazine’s top 50 inventions in 2010. There is a free App available for either iOS or Android called “Martin Jetpack” that provides an augmented reality simulation and also allows you to watch videos of the Jetpack and review technical data. Videos to watch: “Martin Jetpack 5000 feet flight – highlights” https:// youtu.be/SHPedpE70Es “P12 Test Flight April 2014” https://youtu.be/LDp1Xz tObUQ “World’s first commercial jetpack set for 2016 launch” https://youtu.be/rvmuDQjxKxg “Martin Jetpack Flight Demonstration 6 December 2015 Shenzhen, China”; “Martin Jetpack Concept of Operations” https://youtu.be/blg2LfXXqdk Jet Pack International Jet Pack International (www.jetpackinternational.com), based in Colorado, manufactures hydrogen peroxide fuelled rocket packs of the Bell design and puts on spectacular public shows. They offer the H202 model with a flight time of 23 seconds, a maximum distance of 402 metres and a fuel capacity of 16 litres. They also offer the H202A with a flight time of 33 seconds, maximum distance of siliconchip.com.au 762 metres and a fuel capacity of 20 litres. Their new unit code named “Falcon” is under development but no details have been released. Hoverbike Hoverbike (www.hover-bike.com/MA/), based in the UK, is the brainchild of Chris Malloy, of New Zealand, who started his project in his garage in Sydney. It is described as a flying motorcycle and has the approximate configuration of a quadcopter although the front and rear blade pairs overlap each other. It is intended to be flown manned or unmanned. It started out with a two-blade design which was found to be too expensive and complicated to control, with an otherwise elegant design. Compare that with the home made hoverbike of Colin Furze, described elsewhere who also had control problems with a two blade design. Hoverbike is now concentrating on the four blade design. Hoverbike indicate they have had extensive interest in the product from the military and other organisations. Hoverbike is relying upon crowd funding and has so far raised $89,210 of a required $1.1 million (at time of going to press). A lucky donor will win a Hoverbike if the project is successful. The Hoverbike will use a flat twin 4-stroke 1.17-litre 80kW engine and 30 or 60 litres of fuel, depending upon whether secondary tanks are fitted. It will have a fuel burn of 30l/hr, a dry weight of 105kg, a maximum take off weight of more than 270kg and a total thrust of greater than 295kg, with an estimated range of 148km on the primary 30 litre tank and an estimated maximum hover altitude of around 10,000ft. Aero-X Hoverbike Aerofex (http://aerofex.com), based in California, has had the Aero-X Hoverbike concept in development since 2008. It will be able to fly 3 metres off the ground at up to 72km/h carrying two people or a load of up to 140kg. Its flight duration on one tank of fuel is 1.25 hours. It is 4.5m long, 2.1m wide, 1.25m tall and has a dry weight of 356kg. August 2016  23 Colin Furze’s home-made hoverbike. Aero-X hoverbike. It runs on automotive gasoline with a 3-rotor rotary engine. Cost is US$85,000. For a video of the Aero-X, see “Off-Road Hover Bike Will Be Available in 2017” https://youtu.be/uwxaZ9KCdcE Homemade hoverbike – YouTube Build Colin Furze has built a hoverbike which can be seen in a YouTube video entitled “Homemade Hoverbike” at https:// youtu.be/soxxPyaAT1k Within the description of that video there are a number of links to various aspects of the build plus his other projects. Also see a Q&A on the build at www.vessel.com/ videos/aHh3cE8s5 His website is at www.colinfurze.com The hoverbike is powered by two para-glider motor units with their propellers and support frames. He says that control is very difficult and solutions to the control problem are not so easy, especially as the machine barely generates enough thrust to lift the rider so additional weight is not feasible. Nevertheless, the vehicle does work. He notes he may build a Mark 2 version which might inFlight using a Jet Pack International jet pack. clude a carbon fibre frame and larger propellers and motors and some ideas to make the device more stable. Catalin Alexandru Duru’s “Hoverboard” Catalin Alexandru Duru invented a battery powered “hoverboard” which seems rather similar to an octocopter that any drone enthusiast might fly but obviously scaled up to be much more powerful and sophisticated. He set the Guinness Book of Records mark on 22nd May 2015 for the furthest flight by a hoverboard at 275.9m with a flight time of around 90 seconds. His company, Omni Hoverboards (http://omnihoverboards.com) is working on a next generation however no details are available on the website. For a video, see “Farthest flight by hoverboard - Guinness World Records” https://youtu.be/Bfa9HrieUyQ Zapata Racing Flyboard Air Zapata Racing (http://zapata-racing.com/en/) is a company that produces hydro-propulsion equipment for water sports that enable a user to launch themselves into the air with powerful water jets delivered to the user via a hose connected to a powerful pump in a floating vehicle. The user remains tethered to the vehicle via the hose so is not capable of independent flight. They took this concept to the next level with the development of an independent jet powered platform called “Flyboard”. The Flyboard has six small jet engines, four internal engines to provide lift and two mounted on the outside Chris Malloy’s Hoverbike in ground-tethered test. 24  Silicon Chip siliconchip.com.au to provide stability and forward motion. The four internal engines produce around 186kW each for a total of 755kW or around 1000hp total. There are on-board electronics to stabilise the device similar to what are used in a drone. The stabilisation software works by controlling the inclination of the thrust nozzle of the internal jets and the speed of the two side mounted jets. The Flyboard is not easy to fly and its inventor, Franky Zapata, says it is impossible to fly without 50 to 100 hours experience on their water jet version of the Flyboard however they are working on a model that is easier to fly and can be used by the general public and military. Unlike some other personal flight systems, this one has some redundancy and can fly if one of the four internal motors fails. It also has triple redundancy of the WiFi channels it uses and the stability sensors. Jet A-1 fuel is carried in a backpack worn by the pilot. The inventor has plans to ride the Flyboard into the clouds and will carry a parachute for safety. The inventor has also fallen into the water many times during experimental flights and says that he has not been hurt doing so. The Flyboard is capable of reaching an altitude of 10,000 feet, has a top speed of 150km/h and a flight duration of ten minutes. On the 30th April 2016, the Flyboard achieved the world record distance for a hoverboard reaching 2252.4 metres. were retrieved from the ocean within ten minutes. In 2011 he flew across the Grand Canyon and the FAA, the US Government agency responsible for aviation regulation, classified his wing and him in combination as an “aircraft”. For a video of Jetman in action see “Yves Rossy: Fly with the Jetman” https://youtu.be/x2sT9KoII_M Tecnologia Aeroespacial Mexicana Tecnologia Aeroespacial Mexicana (www.tecaeromex. com/ingles/indexi.html) is a Mexican company that specialises in hydrogen peroxide rocket engines for various applications such as rocket packs, a helicopter with rocket propulsion at the blade tips (tip jet), rocket powered dragsters, rocket bikes and a rocket car. They manufacture rocket belts to order and sell them to suitably qualified individuals, along with equipment to make high test hydrogen peroxide which is otherwise almost unobtainable. Aerochute Aerochute (www.aerochute.com.au) is an Australian company based in Melbourne that produces a powered one or two man parachute called the Aerochute. The product was discussed in the May 2015 issue of SILICON CHIP, at The Jetman Yves Rossy, otherwise known as the Jetman, developed a rigid 2.4m span wing with four small jet engines which he attaches to his back. His body acts as the fuselage and he controls the direction of flight by moving his body. The engines are modified Jet Cat P200s which are the largest type of model aircraft jet made by Jet Cat with a thrust of nearly 24kg each. See www.jetcatusa.com/rc-turbines/ turbine-details/p200-sx/ To launch, Jetman dives out of a helicopter as the aircraft has no landing gear; except for his legs! When it is time to land, he releases a parachute and floats to the ground. Jetman has flown as fast as 304km/h with his jet-powered wing and crossed the English Channel in 2008,‑ reaching as much as 200km/h for the 13-minute, 35km flight. In 2009 he attempted to cross the Strait of Gibraltar but was forced down by strong winds just a few kilometres from Spain. Fortunately, he was not hurt and he and his machine Record breaking (at the time) flight of hoverboard. For safety reasons this flight, and that of other similar vehicles are made over water to minimise pilot injury in the event of engine or other failure. siliconchip.com.au Alexander Duru and his hoverboard. Essentially it is an octocopter. Image by Daniel Petkov August 2016  25 Jetman’s jet powered wing in a folded state for transport and also so he can get into helicopters prior to launch. be used to pick up or deliver supplies. Another application of the remotely operated vehicle is for aerial surveys, perhaps with remote sensing or photographic equipment. A final development of this company is a “fly by wire” control arrangement whereby the pilot guides the vehicle via a joystick rather than the traditional controls (which remain for the purpose of redundancy). Troy Hartman Jetman in flight. Note the four small model aircraft jet engines. Flight is controlled by him moving his body. The fuel used is kerosene. Troy Hartman (www.troyhartman.com) is an aerial stuntman who attached jet engines to his back that produced 90kg of thrust to propel himself with a paragliding wing. You can watch a video of his flight at “The Troy Hartman Jetpack” https://youtu.be/Yolum7_0UCA Jet Powered Wing Suit the Australian International Airshow. The company is engaged in ongoing development, in conjunction with the Swinburne University of Technology, of an electric version of this vehicle. A remotely operated version of the vehicle has also been developed which has range of 3 hours or 180km. While it can fly unmanned, it retains its seats so that it could fly to a remote area, pick up one or two injured people and then fly back. It could also Flyboard Air. Note the fixed boots which keep the pilot attached to the aircraft. Also visible are the two outboard jet engines. Not visible are the four internal jet engines. 26  Silicon Chip Finn Visa Parviainen developed a pair of jet boots to propel his wing suit for level flight and even climb until he runs out of fuel. He then lands in the usual way of winged suit flyers, using a parachute. For a video of his flight see “Phoenix-Fly: Wingsuit Jet Pilot” https://vimeo. com/16632926 Airvinci As we went to press, Canadian company Airvinci announced that their single rotor, dual-engined “backpack helicopter” was ready for a trial flight. The brainchild of Tarek Ibrahim and developed in his suburban garage, his dream was to develop a safe, compact and affordable means of transport, even if only to miss the daily traffic jams by flying users between home and the office! Flyboard Air in operation. Source: Zapata Racing. siliconchip.com.au Initially conceived as a heavy-lift drone (left), Airvinci now plan test flights for their humancarrying model (right) next year. Visa Parviainen in flight with his wing suit and jet boots. Comparisons have been made between it and the Martin Jetpack but Airvinci claim their craft, also a ducted fan design, will have a far greater range and with two engines, will be much safer than single-engine designs. Initially developed as a heavy-lifting drone helicopter, the Airvinci has now morphed into a full-sized, personcarrying VTOL model. This is expected to undergo trials during 2017. Ibrahim says that the Airvinci will have multiple appications; as well as a traffic-snarl-beater, he sees it being used as a “sky taxi” to take users direct from their homes to airports for their flights, or even as a launch vehicle for skydivers, taking parachutists up to 12,500 ft and then automatically returning to their base once the occupant has jumped out! siliconchip.com.au He also envisages a huge number of applications in search and rescue, firefighting, public utilities and so on. Airvinci website is www.airvinci.com, where there is also a video of the Airvinci presentation made at TEDx Toronto last October. Conclusion A wide variety of personal flight systems have been developed over the years and continue to be developed. Safety is of paramount concern and if these systems are to become widespread for personal transportation they must be failsafe in the event of an engine failure, either by generating lift with a wing such as the Aerochute or with a ballistic parachute as with the Martin Jetpack. SC August 2016  27