Institute of Aircraft Design

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Seven at one blow

Klaus Ohlmann’s record rush in a electric airplane Ever heard of the “e-Genius” before? “e” like Einstein the science-“genius”? Wrong! The e-Genius is the best electric airplane in the world, though nobody seems to care by now. After achieving seven brand-new world records in the category of landplanes using electric drive that should be a thing of the past.

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The singleton arose from the team around professor Voit-Nitschmann, from the University of Stuttgart’s Institute of Aircraft Design. Back when holding the chair of aircraft design, the passionate aviator Voit-Nitschmann already was accountable for the game-changing solar airplane icaré. His team of engineers and students accomplished to bring a completely new airframe from a scratch to its maiden flight in May 2011, in a pretty short period of time. And this at a German university.

Initially the plan was to realize the plane, back then called “Hydrogenius”, with a fuel-cell from the automobile sector. When a NASA-sponsored flight-competition for the most efficient plane was advertised by US-American CAFE-Foundation, a fast-pace plan was needed. So the team decided to install a huge battery-system as an energy source. As one of the pilots, I had the honor to accompany thise outstanding plane almost from the outset. Test flights in Mindelheim, Germany and California ended up in the NASA competition in autumn 2011 in Santa Rosa, where I was at the controls of the e-Genius. In total the plane had, by far, the lowest consumption of all competing airplanes. But due to the competition rules, which were looking for the lowest consumption per passenger, the team scored 2nd. It was slightly beaten by the twin-fuselage four seater design by Pipistrel.

The next milestone was achieved at last year’s Green Speed Cup in Strausberg, Germany, where the goal was the best speed at the lowest consumption. To fly energy-conscious by taking advantage of thermals and wind is also really challenging for the pilot. As expected, the e-Genius outpaced the competitors, manly powered by piston engines, due to the technical superiority. Its average consumption was roughly one fifth of the 2nd placed Stemme S10. The flight over 405 km (252 mi), an unofficial distance world Record, not only amazed the other competitors.

Unfortunately, we had to skip the interesting completion this year, as the schedule was too tight, due to test flights. Alternatively Dipl.-Ing. Len Schumann, head of the project, offered me to bring the plane to Serres, France, instead where I could test the e-Genius to the top of my bent as part of the trail. After taking a look at the Sporting Code for powered flight, it was clear that there are lots of records which are just to be established. Along the lines of “do good and spread the word” the e-Genius was at the airfield of Serres two weeks later.

As the airplane came without its team, it was simultaneously tested, if an experienced pilot can handle the technology by himself. The first thing Len showed me was the charger and its operation, so I could always “refuel” the plane. Fortunately I had the required AC at the field, but the fuse was too weak. So I had to charge a little slower. A check-out flight gives the opportunity to get to know some convenient improvements, which the team had realized since the last flight at the Green Speed Cup. Most notably is the partitioning of the cockpit, which makes flying the e-Genius even more silent. Together with the custom-built MT-propeller-blades, which are currently on trails, the silence in the cockpit is stunning.
Already on the next day it immediately gets to the point. br />Speed on a 100 km roundtrip: the first shot with 198 km/h, fails as the logger was set incorrectly. The second attempt, one day later, worked out, although the speed was only 179 km/h.

Christopher Ritter, a friend of mine and a real freak when it comes to electrics, comes especially all the way from St. Auban with his Tesla S, which currently appears to be the best standard produced electric car. Christopher “refuels” his batteries with the solar-roofed carport. He can drive about 80 percent of its kilometers with solar energy, which is a great opportunity for mobility of the future. The acceleration of the 400 hp electric car is simply breathtaking and the range of 280 km (236 mi) is considerably better compared to the other electric cars on the market.

500 km speed and distance record:

The perfect day has come but my official observer had used the outlet for something else. What he didn’t know: To protect the batteries, one can only charge them if they are discharged to a certain level. The result is a state-of-charge of only 85%. That, for sure, is not enough for the flight which shall be farther than every flight before. I use that day, to get an impression of the gilding performance of the, with 900 kg (1984 lb) MTOM, not lightweight motor glider. 300 kg (661 lb) of battery, housing, wires, control and safety units make a significant difference. At a wing loading of approximately 65 kg/qm (14lb/ft²) and only 17 m wingspan, you need some strong updraft to climb reasonable. The best endurance speed was measured in the framework of an IDEAFLIEG-measurement in 2012 at IAS 118 km/h with 1,11m/s descent-rate. The maximum lift-to-drag-ratio of roughly 30 at 135 km/h, with feathered propeller, provides a lot of security in case of a system-failure, which one should always keep in mind while flying an experimental.

The day after, it is finally happening. We file a task from Serres northbound to the turning point north of Zermatt and back.

There are two ways to make this, a little more than 530 km long, tip. Either you exhaust the battery, which ruins them, or you find an elaborate routing. As I’m very familiar with the region and a passionate glider pilot I for sure had some advantages to find that route. Some serious obstacles are those high mountain passes and the required altitude to hop over them. Most of the energy is needed for the climb, hence the plain would have some obvious advantages. Immediately after take-off with 75 kW I reduce the power to 15 kW and use every thermal in my shallow climb-out. The routing leads via Gap and through the Durance-valley, to Mont Dauphin, where I expecte a climb along the mountain ridge in the slope wind. The solpe wind is, by far, not as strong and consistent as expected, which was already the first disappointment on that day. After an endless time I finally reach an altitude, meeting my idea of safety in the valley of Briancon. A prototype, like the e-Genius is worth around 1.5 million Euro and is not comprehensively insured. Reason enough to confirm the engineers trust in my skills in all conscience. At the Tete du Peyron I find a strong updraft, finally lifting me and the “heavy metal” to the desired cruising altitude. With a power-setting of 13 kW I can hold 3700 m with a groundspeed of 160 to 170 km/h. Via Bardonecchia I enter the upper Maurienne-Valley, passing the blue gleaming Lac du Mont Cenis. Col du Caro, Gran Paradiso, Aosta …. the electric motor runs like a clock. Abeam the Matterhorn I can see the spectacular glaciers of Monte Rosa. Some gliders circle beneath the few, but very high cumulus clouds.

I reach the turning point north of Zermatt. But will the remaining energy in the big belly of my high-tech-toy be sufficient to make it back to Serres?It will remain exciting, using more than 43 kWh will at least chip away the expensive Li-Ion batteries useful life.I switch the propeller-control-unit from constant-speed to manual. After pulling the RPM back to a low 1150 and the power to 12 kW there is only a silent sigh remaining from the rear. I inspect very single cloud on my heading and follow every mountain ridge that might spend some energy.Monte Rosa, Aosts, Gran Paradiso…I have almost no time to appreciate the beauty of the mountain range surrounding me. The sole thing I have on my mind is the remaining energy in those four carbon-fiber boxes aft of the cockpit. The pilot becomes the single most important interface between the numbers visualized on the color screen: RPM, power, temperature, consumption and residual voltage. Shortly before Bardonecchia the voltage indication of the lowest cell drops from 3,4 V to 3,3 V and starts flashing red. From now on I have to act very carefully unless I want to torture those batteries. My tension is inversely proportional to the batteries voltage. I am in 3800 m, would love to hold that altitude but I don’t want to run a risk for the battery. I turn off the engine, feather the prop and glide into the, thermally well-looking, Durance-Vally heading to Briancon. From my comfortable altitude I can safely reach an airport, but I want to get home and for sure I want that record. To reach Serres in a glide configuration safely I have to cross the Pas de la Cavale in at least 2800 m. North of Briancon, I can benefit from a strong updraft. Actually, I should be high enough now, but to be sure I indulge in some more meters above the Tete d’Amant.

In a silent glide I descend homebound. A quick boost with the engine north of Gap ensures an uneventful final approach. After landing the screen indicates an energy consumption of 42.5 kWh for a distance of 536 km. In case of need there would have been hidden reserve of half an hour, therefore my energy management worked out pretty well. In France the electricity consumed equals roughly energy costs of4.20€. Result: Modest 93 km/h for the speed record over 500 km and a new distance record in electric flight of 504 km

On Saturday morning, the batteries are fully charged again. As I only have the plane for one week, I want to get three records in one flight, today. First of all the highest altitude, followed by 90 seconds in level flight then finish with a speed record over 15 km.The weather is fair, heavy winds from the south and some showers are forecasted. My take off was pretty late, I also want to climb fairly slowly to have sufficient power for the final high-speed flight. My big ship twists skywards cozy. Unfortunately an unpleasant rain front is coming up from the west. I didn’t expect that. The rainy altocumulus passes directly through my block altitude. I can barely get around it and the raindrops on the wing don’t enhance climb performance. Finally the shower dissipates and I can enter the area north of Pic de Bure. In 5600 m, the old record of 4500 m way below me, I contact Marseille and request clearance to flight level 210. Shortly after, I am cleared to FL210 for 10 minutes with the transponder operating. I set the power to 25 kW and ascent quickly to 6370 m. 

Time for 90 seconds level flight.Due to the clearance from the nice controllers at Aix and Marseille, I even managed a third altitude record, “time to climb to 6000m”. With the spoilers deployed I descend towards the next record. Now it’s about to get the fastest speed for a distance of 15 km, which have to be flown twice opposed. As agreed upon with the responsible test director, professor Voit-Nitschmann, I can test speeds up to 230 km/h. The e-Genius’ Vne is 270 km/h, but for certification it had to be flown even to 300 km/h (Vd)! South of Serres I head towards the compulsory departure fix. I can only change my altitude up to 100 m until reaching. No I have to keep the power, engine temperatures, voltage, indicated airspeed and altitude in sight.

The current record holder Chip Yates set the record to 225 km/h.After the first run westbound, I fly from the western approach fix back eastbound and carefully keep that altimeter in sight so I would end up above my starting altitude. I’m totally unfamiliar with records over such short distances.After touching down in Serres and evaluating the data the logger recorded, it is clear. I managed three new altitude records and a speed record over 15 km with a speed of 229.7 km/h.

The target, to stage the currently best electric airplane in the world, is attained.To establish gliding between the poles of high-tech, e-motion and renewable energy as a new advertising medium for the future “zero emission – energy industry”, it needs some more work.But as I’m very confident with that, I will not rest until our fascinating sport will receive the earned reception.

My vision:

I can barely imagine, that in 10 to 20 years there will be a future for piston engine aircrafts in the general aviation. The progression of batteries and energy systems, whether fuel cell or range extender, in the different segments of the industry, will also change the propulsion technology in aviation. Fast charging systems and significantly higher capacity at a lower weight and price, while reducing the noise considerably, will bring the upstage pilot community to convert to electric flight. By simplifying the system, flying will become easier and the maintenance costs will be reduced immensely.Electric towing planes could soon supersede our expensive gas guzzlers. Electric self-launching gliders do already exist.

There’s a time for everything … e-motion isn’t stoppable anymore…..

Klaus Ohlmann

See gallery here.


e-Genius at ILA & Airbus Toulouse

e-Genius paticipated in the flight display of the ILA Berlin Air Show and was later presented in Toulouse to Airbus test pilots and engineers.

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The research aircraft e-Genius that has been developed and built at the University of Stuttgart was presented at the ILA Berlin Air Show from 11 to 16 September 2012. Furthermore, the e-Genius even took part at the flight programme. The aircraft was placed at a prominent place direct on the Airbus stand, where the most modern electric aircraft in the world could be presented to the 250,000 visitors.

Even though the e-Genius was not able to compete against its neighbors A380 and A400M regarding size, the fair visitors expressed their great interest in the new, electric propulsion technology. e-Genius demonstrated its superiority in terms of lacking CO2 emissions and hardly perceptible operating noise by starting behind a Russian MiG-29 fighter jet. The very good performance of the e-Genius was demonstrated by its pilot with fast climb and curve flights.

Three days later and 2,000 km further to the south, the 'e-Genius Day' took place at Airbus in Toulouse, France, directly after the ILA Berlin Air Show. Besides presentations about the development, the construction and flight tests of the aircraft, the experts from Airbus could take the opportunity to complete their first flight as an e-Genius copilot and experienced the electric flying in first hand. The pilots Prof. Rudolf Voit-Nitschmann and Klaus Ohlmann demonstrated the good-natured flying characteristics and the suitability for everyday use of e-Genius among others to Robert Lafontan (Head of Aircraft Architecture and Integration), and Jacques Rosay (Vice President Chief Test Pilot). All in all, e-Genius took-off for 19 times in Toulouse. The final flight back in home direction from Toulouse to Montelimar via the Massif Central (300 km) represents the longest flight route ever flown by e-Genius up to now. See gallery here.


'Übermorgenmacher': Tribute to Five e-Genius Team Members

Our five awardees from the e-Genius team with Minister Theresia Bauer

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The State of Baden-Württemberg honours leading engineers of our team for their new concepts for innovative and ecological flying. The distinction took place in the government department for science, research and arts on the 25 July 2012. The trophies have been handed over by Minister Theresia Bauer. In her honorific speech she expressed: "The competition aircraft e-Genius is probably the most modern electric aircraft at present, unmatched by the competitors concerning speed, energy consumption and noise exposure. Today, we not only honour the idea, but rather the sensational performance of the team around Professor Voit-Nitschmann."

All in all, there have been 500 applicants for the prize. The jury honoured 60 persons, it is remarkable that five of them are from our team! Please click on this link to see the official 'Übermorgenmacher' website. Here you can find a short overview of our awardees:

2Professor Rudolf Voit-Nitschmann is the leader of the e-Genius project since 2005. He guided the development with his experience and knowledge by starting with the concept study of the Hydrogenius, a hydrogen fuel cell powered two-seated aircraft. With help of the new knowledge of this study he guided the realization of the e-Genius.
You will find many details of its history and performance in the homepage category "Aircraft".

2Dipl.-Ing. Len Schumann developed the basic concept of the Hydrogenius in his diploma thesis in 2005. As the chief manager for the airframe and aerodynamics of the e-Genius he was significantly involved in the today´s appearence of the e-Genius. Today, he is one of the two deputy managers of the project and coordinates the further development of the aircraft.

2Dipl.-Ing. Steffen Geinitz was the chief engineer of the propulsion system for both Hydrogenius and e-Genius. Since the development concentrated on the e-Genius, he realized its propulsion system consisting of four rechargeable lithium-ion batteries. Their capacity is bigger than any ever been installed in a car.

2Dipl.-Ing. Karl Käser was the lead manufacturing engineer of the e-Genius during its "hot" building phase from 2010 to 2011, when the e-Genius had its maiden flight. The e-Genius team started the manufacturing of the fuselage only nine months before!
Dipl.-Ing. Karl Käser has its own engineering office titel_small and worked as external employee for our project.

2Dipl.-Ing. Clemens Gerlach was the cheif electrical engineer. He took part at the development and construction of the battery system as well as the integration and initiation of the propulsion system. Furthermore, he developed and integrated additional monitoring systems.
Dipl-Ing. Clemens Gerlach works for the SFL GmbH and worked as external employee for our project.


NASA Green Flight Challenge

The e-Genius team with the second prize trophy of the Green Flight Challenge and the Lindbergh Electric Aircraft Prize

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e-Genius succeeds in CAFE`s Green Flight Challenge (GFC) as the quietest airplane in the world. The e-Genius team has won both prizes for the quietest aircraft and second in the overall standings.

The e-Genius team proudly announces its successful performance at the Green Flight Challenge 2011, taking place at the Sonoma County Airport, Santa Rosa, California. Based on the competition flights, the e-Genius team gets the second place in the overall standings of the GFC, detained by NASA. A total number of 13 teams attempted to participate in the final competition of the GFC, but only three were successful.

It was a close fight for the first place between the Slovenian Team from Pipistrel and the Institute for Aircraft Design from the University of Stuttgart. The used energy was not counted by plane, but per passenger. In presenting an unusual four seat-prototype with two fuselages, Pipistrel tipped the scales. The third team Phoenix had no chance against the electric motorization due to its combustion engine.

During the GFC itself and its exposition at Moffett Field, CA, the e-Genius performed eleven flights, six more than the other aircrafts and seven more than required. The total flight time exceeds eight hours. Until now, seven pilots had flown the e-Genius. In contrast to the winner's plane which had been exclusively flown by highly experienced test pilots, replacing the two passengers by concrete, the e-Genius demonstrates to be suitable for everyday use.

The e-Genius team also won the Lindbergh Electric Aircraft Prize (LEAP), presented by Erik Lindbergh, the grandson of Charles Lindbergh. This prize characterizes the quietest aircraft of the competition, in this case the e-Genius with a take-off noise of about 60 dB. This is equivalent to a TV with normal volume at a distance of one meter!

We are very proud that our aircraft was able to fullfill all GFC requirements with outstanding performance and is anyway suitable for every day use. In the future we might know if e-Genius is the prototype for powerful electrical flight. In the result list releasd by the CAFE Foundation you can see the amazing effectiveness of our aircraft. The e-Genius team is very happy about this successful result. We want to thank all the sponsores and supporters for their help making the e-Genius project possible and that successful. See gallery here.