A Tale of Three Pauls

Dean Sigler Uncategorized 3 Comments

Dr. Paul Robertson lectures at Cambridge University’s Engineering Department, and Paul Dewhurst serves as Director and Chief Flying Instructor at Flylight Airsports, Ltd.  The two Pauls made simultaneous takeoffs March 1, 2009 in Britain’s first two electric aircraft.   A third Paul, Welsh by name, acted as certification engineer for the effort. Dr. Robertson took to the skies in a Dragonfly hang glider powered by a Geiger/Eck 10kW motor/controller/propeller combination, while Dewhurst became skyborne in a Lazair ultralight propelled by a pair of Plettenberg Predator 12 kW (peak output) model airplane motors.  This testbed in particular reflects Dr. Roberton’s studies toward the constuction of a sub-115 kg electric twin called Hummingbird.  His PowerPoint presentation shows the mathematics of powering such a craft on model aircraft motors, the batteries required, and the anticipated and tested thrust for successful performance. The fact that practical outcomes matched mathematical projections attests to the care involved in his analysis. The presentation provides a good model for others who …

A Great Year and Gala Day for Yuneec

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 Last year, we knew Yuneec for its tidy power package for paramotors, the 10 kW EPac.  We were awaiting developments on the EP200, a twin-motored, single-place ultralight that looked as though it would be powered by two EPac units.  Springtime, 2009 brought the news that a two-seater was under development, and summer brought surprise after surprise.  The 40 kW (54 horsepower) E430 made its first flights on June 12, 2009, followed by further testing on June 20.  Test pilot Sun Xun managed two flights of 15 minutes, achieving a top speed of 150 kilometers per hour (93 mph) a climb rate of 7 meters per second (1,377 feet per minute), and a maximum altitude of 300 meters (960 feet).  Sun commented on the quiet and smooth nature of motor operation. The prototype was quickly bundled up and shipped to Camarillo, California, where test pilot Dave Morss and members of EAA Chapter 723 gave the airplane a more stringent shakedown, in …

A Smart Electrical System for GA

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Dr. Seeley made this available to Green Flight Challenge competitors. As a follow-on to your ideas for simplifying pilot licenses that I presented at Electric Aircraft Symposium III: Here is a link to a very encouraging development debuted at Sun & Fun: A comprehensive, integrated, smart electrical system for GA from Marc Ausman at Vertical Power Corporation ($1500 – $12,000). This looks like a very helpful reducer of pilot workload to help make flying simpler. The more up-scale versions offer redundancy and this technology should save weight and free up panel space as well. Also, the array of COTS eCFI/flight control options from MGL Avionics is very impressive too. Sure wish I had time to build a homebuilt aircraft with today’s technology!

Solar Impulse Rollout and All Motors Running

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November 6, 2009, Solar Impulse left its hangar and Markus Scherdel, the project’s test pilot, ran all four motors on the giant craft.  This marks the beginning of ground testing for HB-SIA.  “With its engines running at full power, it gave the impression of wanting to get off the ground straightaway …but it won’t be long now before we release the brakes and let it roll its first few meters,” said André Borschberg, co- founder of Solar Impulse.  The four motors achieved full power at 400 rpm. Bertrand Picard, the originator of the project, was equally enthusiastic. “For the whole team, the impression of seeing it completely assembled, majestically reigning over the Dübendorf tarmac was very intense!  We just can’t wait to see it fly, culminating 6 years of work.”  Testing will now continue, with taxiing trials, followed by increasingly quick runs down the Dubendorf airfield runway until initial “crow hops” are accomplished.  This Swiss-based project results from a huge investment in an …

Ready to Launch

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LaunchPoint Technologies, Inc. announces the highest power to weight ratio of any known electric motor – seven horsepower for 1.4 pounds (635 grams) or five pounds per horsepower.  As a comparison, the tiny Neutrino outrunner by Steve Neu of Neumotors weighs 14 grams and puts out 125 watts, peak.  That would add up to 784 grams at 7 horsepower if that motor were scaled up to match the output of the LaunchPoint unit.  The LaunchPoint motor is not only lightweight, but surprisingly small, scaling only six inches in diameter and one inch in thickness. It is composed of a great deal of carbon fiber in its plate-like structure. Behind this astonishing power output is the use of a Halbach array, “an arrangement of permanent magnets that augments the magnetic field on one side of the array while cancelling the field to near zero on the other side,” according to Wikipedia.  The effect of the array is powerful enough to permit its use …

How Small Can You Make A Gyro?

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MEMS (micro-electrical-mechanical systems) are rapidly becoming hot items in the electronics market. Consider the rather amazing controllers for WII games.  These provide a degree of haptic feedback, partly based on the MEMS inside.  Your iPhone or GameBoy have MEMS devices that allow realistic banking and turning on screen – again based on gyro feedback from MEMS devices. Consider putting this micro-gyro capability into a heading hold and wing leveler device in an electronic certified flight instructor envisioned by the CAFE Foundation, and you can see why this technology holds promise for safer flight and expanded light aircraft capabilities. Eagletree has a range of telemetry and monitoring products for model aircraft that combine this technology with sophisticated radio gear, including video capabilities, and you have a powerful tool for development.

LCA – Life Cycle Analysis

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The Link below provides a conceptual background for the study and chart, which give us insight into life cycle analysis, a valuable tool for determining the true costs of our energy sources. Note in the following that the actual costs and carbon emissions for a product may be greater than those for the actual operation of that product.  Obviously, wind turbines and solar cells are clean in their operation – but what does it cost to manufacture, transport, and dispose of the obsolete or unservicable units?  This is a good tool for making those assessments, but I’d love personally to have even more definition of the “human equivalents” listed in the chart found in the link below.  Perhaps an expert in the field could provide insight. Excerpt of an LCA from the Global Development Research Center D. Case Studies and Examples 1. Wind Farm Materials Denmark conducted a LCA on the energy and emissions resulting from the manufacture, production and transport …

Power Up Front

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Luka Znidarsic and Matija Znidarsic, both experienced sailplane pilots and mechanical engineers in Slovenia, have developed a Front Electric Sustainer, a power system that provides a climb of 1.5 meters per second (198 feet per minute) for their prototype configuration on an 18-meter LAK 17.  They designed their own motor and controller for the application.  The motor is 5 kg (11 pounds), and puts out 15 kW (20.1 horsepower) at 85 Volts.  Total weight for the power package is 35 kg (77 pounds), with batteries in two packs behind the rear spar, balancing the weight of the motor and propeller in the nose. “Front” refers to the motor’s location, right in the nose of the sailplane.  A 0.9 meter (35.4 inches) propeller automatically extends when the outrunner is operating, and folds against the nose of the fuselage when the motor is shut down.  The standard nose cone or motor unit can be mounted when the sailplane is put in its trailer, without …

Richard VanGrunsven on Electric Airplanes

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Despite having produced kits which have led to 6,410 RV aircraft in the air at last count – all carbon-consuming and emitting lightplanes – Richard VanGrunsven owns an electric airplane, an Antares 20E self-launching sailplane. He attended AirVenture 2009, and reports on his findings regarding the current crop of electric airplanes in his article “The Year of the Electric Airplane.” His opinions are worth noting, simply because of the worldwide acceptance of his designs.  He obviously loves his Antares, noting its single-lever motor operation as “almost sinfully simple” compared to the more complex extension/motor start/operation/shutdown/retraction sequences on other motorgliders.   He shows some disappointment in the low performance speeds of present electrically-powered craft, but notes that if the claims of some motor packages were fulfilled, “I’d run right out and get a ‘plug-and-play’ motor system and design an airplane around it.”  Now, that’s an incentive for developers!

Small, Light, and Powerful Paramotor

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MHP-Profi of Austria has developed a lightweight, 20.1 kg (44.22 pounds) paramotor package that puts out 10 kW (13.4 hp), 50kg (110 pounds) of thrust, and allows 17-25 minutes of power.  Videos show the designer climbing the paramotor smartly, and zipping up and down hills on a bicycle in the beautiful Austrian countryside with the power pack strapped to his back.  Most interesting are the two outrunner motors on stalks that can be arranged either vertically or horizontally.  Each motor has its controller close by, a good design strategy, and swings a large wood propeller readily.  The lithium polymer battery pack, at 9.5 kg (20.9 pounds), offers 30 Amp hours’ capacity.  Batteries can be recharged in two hours, or with an additional charger in one hour.  Speed control is infinitely adjustable, with battery “levels” indicated on the display on the pilot’s hand control.   The power pack and sail combination can accommodate pilots from 60 kg (132 pounds) to 85 kg (187 …