2013.05.03 - Godspeed, Bertrand!

23 years after the first solar-powered airplane crossing of the United States made by Eric Raymond flying Sunseeker I, Solar Impulse has launched its own expedition. Bertrand Piccard took off early this morning from Moffett field in California with Phoenix, Az set as his goal. A fitting first leg, Phoenix was also the first destination for Sunseeker I on its journey across America. Performance can be pursued in many forms and the metric that Solar Impulse is after is duration. Using energy stored both in batteries and in the altitude that is gained during the day, HB-SIA is able to glide and cruise at low power through the night. Though it flies at similar airspeeds as Sunseeker I, HB-SIA is able to plan much longer flights because of its incredible duration. 23 years is a long time in the tech world – batteries, solar cell and materials have all improved, but with structural, aerodynamic, and UV requirements all at odds with each other, designing a solar-powered airplane remains no small challenge. Solar Impulse licensed Solar Flight Inc’s solar-cell integration technology and hired Eric Raymond to oversee HB-SIA’s construction.

As we wish Andre and Bertrand favorable winds on their adventure, we prepare our new airplane, Sunseeker Duo for its maiden flight in Italy.

SUNSEEKER DUO

Solar Flight is preparing to test fly a new airplane in the Sunseeker family: Sunseeker Duo. The goal is to acheive maximum performance without using fossil fuels. Not only will the Duo be the fastest solar-powered airplane ever built; it will be the first solar powered airplane to offer a seat for passengers. The Duo incorporates all of the best features of the other Sunseeker aircraft and adds many refinements, not to mention significantly improved technologies. The solar cells used by the Duo are better than 50% more efficient than those used by Sunseeker II. While Sunseeker II is able to cruise in level flight on direct solar power, the Duo will have enough power to maintain a steady climb on direct solar power. The tricycle landing gear arrangement, familiar to all pilots, ensures that the Duo will operate normally at any airport in the world and folding wings give the airplane a hanger footprint no larger than a Cessna 172. The airplane can also be quickly disassembled and packed into a custom trailer.

The Sunseeker Duo realizes Solar Flight’s dream of a practical, high performance, 2-place solar powered airplane. With the US and Western Europe already well explored by Sunseekers I and II, Solar Flight is looking towards the dramatic landscapes of Eastern Europe and Western Asia for possible expeditions with the new airplane. Whether it is a day of local flying above the clouds, or a trans-continental adventure, Solar Flight is a new paradigm for aviation: adventure, freed from the constraints of fossil fuels.

Sunseeker Duo

2013.04.27

This week we brought the Sunseeker Duo to AERO Friedrichshafen for its public unveiling. The airplane is fresh out of the paint shop, and since it is too large to fully assemble in the Slovenian workshop, it is also the first time that we got to see the airplane in its full glory!

AERO is always a special event, a convergence of the best sport aviation manufactures and many interesting projects in development, this year was especially good. Not only do we have a new airplane to show - we were treated to the central display space at the main entrance.

2012.06.17

Today we assembled the major components of Sunseeker Duo out on the ramp for the first time. There is a lot of work left to do, but it is encouraging to see the ship start to look like an airplane! Compared to the original Sunseekers, the Duo is a giant. The switchblade function of the wings reduce its footprint to a managable size for hangar storage.

2011.11.05

The Sunseeker Duo is truly an international effort. Consider that the fuselage was molded at Allstar Gliders in Poland. With extensive support from Germany and Slovenia, the project is gathering momentum. Construction moves ahead, with high quality parts as the rule.

Here we introduce the engineering effort on the nose gear from our friends in Santa Paula, California.

The nose gear is a crucial assembly, requiring shock absorbtion, steering, and retraction, all in a reliable light weight package. Rick McWilliams (http://www.tangentinstruments.com/) designed the trouble free nose gear for the Mermaid amphibian, so he got the job of designing our nose gear under very demanding weight and space constraints.

Partnered with him is John Lynch, whose shop is also at the Santa Paula Airport, to turn the computer files into parts. While most of the parts of the new plane are composite, this assembly will utilize aluminium. The shock absorber is integrated co-axially into the strut to save weight. A carbon pre-preg fork will be tested with the assembly, attaching to the nylon wheel.

2011.08.14

We are making good progress on the wing at the moment. Karl Kaser leads the engineering team starting work on the center section and main landing gear.

2010.03.05

The campaign to build the fuselage was completed at the Allstar Glider factory in southern Poland. Andrej Papiorek, the owner. helped us with materials and construction techniques, not to mention full use of his well equipped workshop.

Many parts, and the molds themselves are provided by Stemme GmbH. The window is from Mecaplex in Switzerland, and was installed by experts in Poland, a tricky job!

The fuselage is molded from carbon fiber, with 100% Nomex honeycomb sandwich.

Roman Susnik brings to our attention the housing for the new motor he is developing.

FLIGHT LOG

Adventure is inevitable when you fly experimental aircraft. Solar Flight's solar-powered airplanes have logged more time than the combined total of every other solar-airplane in the world. The Sunseeker family has flown in seven countries, crossed mountain ranges, deserts, and continents, faced wind, rain and snow, and set speed, distance, altitude, and duration records many times. But the Sunseeker aircraft are designed to do more than set records and accomplish feats – they are designed to be practical sport machines. Long quiet days in the mountains, in the bright sun above the clouds, with an open canopy and unlimited free energy.

2012.08.06

With south winds here in Slovenia, we have the chance for mountain waves. I flew around for almost four hours finding nothing, even though there were lenticulars overhead. I even motored us to 12,000 ft, looking for wave lift. I finally gave up and headed out over the airport, but then I found wave lift right over the runway. With 32 knots of wind showing on my GPS, I slowly crabbed over to Triglav Mountain, while climbing to over 15,000 ft. It is a strange feeling to be downwind of such big mountains in such strong wind, but it was perfectly smooth.

2012.06.07

Yesterday We made a SUNSEEKER flight for RTV Slovenia. Irena went up in a hot air balloon, to take pictures, along with the TV crew.

2011.09.03

50 years of flying for the aero club in Motiers Switzerland was celebrated with an air show, showcasing a wide variety of aircraft.

Irena and I first stopped at Mollis, and enjoyed the hospitality of the glider club there. I flew the SUNSEEKER on the ridge over the airfield, and Irena joined me in a club DG-500.

The day before the show was perfect weather, and all the pilots practiced their routines. I was asked to make a low pass, so I did. Later I found out that a low pass could not be lower than 50 meters, so the pass for the show was much higher!

Swiss TV was there for an interview, and some friends and relatives came to visit.

2011.04.17

Held this year in conjunction with the largest airshow in Europe, AERO in Friedrichshafen, Germany is now history. The winners were chosen from the pilots who completed the flight task, to Ulm and back. As the planes competing were so different, the judges chose three winners, each from a different class.

Solar Flight received 45,000 Euros for the SUNSEEKER II. Axel Lange also received 45,000 Euros for his production Antares motor glider. In the ultralight catagory, Manfred Ruhmer won 10,000 Euros with his electric SWIFT. Find more info about the berblinger prize here: http://www.berblinger.ulm.de/html/press_pm

2010.10.31

Today the European division of Airtech Advanced Materials Group in Luxembourg announced that they will support Solar Flight's effort to develop new solar powered aircraft. AirTech Europe supplies the continent with the best vacuum bagging and composite tooling supplies available to the aerospace industry.

These quality material are crucial for the production of the new SUNSEEKER DUO wings, as they are being made from pre-pregs, to resist the high temperatures generated by the solar cells.

PARTNERS

Technical Alliances

Solar Flight's technical alliance are technology leaders of sport aviation. They contribute major resources to the construction of the Sunseeker Duo.

Allstar PZL
Stemme AG
University of Stuttgart

Materials and Systems Support

Solar Flight demands the best from every material, every component, and every system that it uses in its aircraft. The companies that support Solar Flight are the best in their fields.

Airtech
Amber Composites
Bixby International
DuPont
Evonik
LX Nav
REC BMS
Sunpower
HERITAGE

Günther Rochelt

Musculair II in flight

After a successful hang gliding career and constructing several of his own gliders Eric Raymond was invited by Rochelt to fly his human powered airplane, Musculair II. Musculair II was groundbreaking in its simplicity and to this day remains the fastest human powered aircraft ever built. With Rochelt's encouragement, Raymond conceptualized the original Sunseeker. The configuration was based on that of Musculair II and Rochelt passed on the novel construction techniques that he used to acheive phenomonally lightweight, yet robust structures.

Passenger Flight Solair II crew

In addition to the series of human-powered airplanes, Rochelt built two significant solar-powered ships. Solair 1 was based on a Hans Farner canard design. It employed 2499 wing-mounted solar cells giving an output of between 1.8 and 2.2 kW. The aircraft first flew at Unterwössen, Germany on 21 August 1983. It flew for 5 hours and 41 minutes. The airplane is now displayed at the German Museum in Munich Rochelt's second solar-powered airplane, Solair II, made its first flight in May 1998 and further test flights that summer, but the propulsion system overheated too fast and development stopped when Günther Rochelt suddenly died in September 1998. More information about Rochelt's many projects can be found at solair.de

Solar Flight's efforts are dedicated to the memory of Professor Günther Rochelt.

Sunseeker I

Boy and His Dog
Sunseeker At The Shop Sunseeker With Solar Car

Solar flight was established to further the development of solar powered and electric sport aircraft. Eric Raymond's dream of solar powered flight began in 1979, when Larry Mauro demonstrated his solar powered ultralight glider, named Solar Riser. 1981's debut of Paul MacCready's Solar Challenger added credibility to the concept. The revelation, after flying Günther Rochelt’s Muculair II, that a fast, streamlined aircraft could be built for incredibly low weight was the impetus that led to the construction of the Sunseeker. Design of Sunseeker I began in 1986. Progress was slow until 1988, when support was found in Japan. With the help of several corporate sponsors. Sunseeker I was test flown at the end on 1989 as a glider.

In early 1990 battery powered flights were made with two brush motors driving a variable pitch prop, which could be feathered for gliding. The motor and prop mechanism were not satisfactory, so an A.C. brushless motor and a folding prop were installed.

Across America

Cunim
Sunseeker I Desert Sunseeker I at Chanute airport

Solar Flight’s first airplane, Sunseeker I, was designed for a mission to cross America, a feat it accomplished during the summer of 1990. The expedition began in the Southern California desert and with 21 flights ended in a field near the site where the Wright Brothers first flew.

"With average conditions, I could cross about one state per day, with the first landing being just northeast of Phoenix AZ, after an 8 hour flight.

At my slow flying speed, I often flew in formation with flocks of birds. Nearing the Appalachian Mountains, I flew with the same three black birds two days in a row. They were still following me when I reached the highest part of the mountain range that I needed to cross. I decided the safest thing to do was to fly up through the clouds, so I could fly over the tops of all the clouds and mountains.

I switched on my simple blind flying instruments, but even with my head down, I noticed the three black birds, hovering just above and to the sides of my window. The thicker the cloud, the closer they stayed, but they never left, until we were in the clear again."

  • Eric Raymond

It was the first crossing of the United States made by a solar-powered airplane; an affirmation of the technology's potential and a milestone in aviation history.

Edelweiss

Edelweiss
Edelweiss from below Edelweiss at Tahachapi

The Edelweiss was the second airplane produced by Solar Flight. It was built in response to a debate as to whether it was possible to construct a high performance sailplane that weighed less than the ultralight category weight limit of 154 pounds. AlthoughSunseeker I was initially flown as a glider with an empty weight of only 100 lbs, it was considered too fragile to be practical. More durability was built into the Edelweiss, with less wing span for better maneuverability and a higher top speed. It is designed for a top speed of 120 knots and is fully aerobatic. One of its design features is the inclusion of water ballast tanks in the wings, capable of carrying 150 lbs of water. The wings were load tested to 6.6 g before flight testing.

Sunseeker II

SunseekerII

In 2006 many improvements to the original Sunseeker were completed. The new airplane, dubbed Sunseeker II, featured a redesigned wing with more area for solar cells, a more powerful motor, new lithium polymer batteries, and an updated electrical system. In 2009, again with Eric Raymond in the cockpit, Sunseeker II completed a vast flying tour of Europe. The tour began with the first crossing of the Alps ever made by a solar powered airplane and continued down the length of Italy to Sicily, followed by a route along the Dolomites through Austria and Slovenia, and finally a journey through the South of France and Spain ending at Spain’s southern coast.

Sunseeker I and II have logged, by a huge margin, more flight hours than any other solar powered airplane. The Sunseeker, unlike other solar powered aircraft that have been flown in ideal conditions under strict ground supervision, is the only solar powered aircraft to have been tested and proven in continuous real world operations.

First Alps Crossing

Crossing the Alps
Alps Cockpit Arrival

99 years after the first crossing of the Alps in an airplane by Geo Chávez flying a Blériot XI, Eric Raymond completed the first crossing of the Alps made by a solar-powered airplane flying Sunseeker II.

"It was one of the most difficult things that I have ever done, but it was also the most beautiful flight I have ever made. It was very cloudy, but after fighting to gain altitude I got over the clouds and cruised on direct solar power, eventually climbing to 13,700 ft. It was amazing to see the peaks of the mountains coming upthrough the clouds. I could clearly see the Matterhorn and Mt Blanc over the clouds. I could not see anything in the direction of Italy, except a solid wall of clouds. I tried to climb over them on course for Torino, but I had to fly between towering cumulo-nimbus clouds. I was in bright sun, when I noticed that I was flying through large snowflakes. That was the first sign of trouble. Soon I was trapped over these rising clouds, with my escape closed off. I was climbing at full power, but the clouds were rising faster. It was snowing on me, even though I was in the sun! Desperately flying around in my shrinking trap I found a small hole, where I could see the ground. Just snow and trees. I turned off the motor, set the airbrakes, and spiraled down 7000 ft, until I was just under the clouds. I wanted to take a picture of the snow, but I couldn’t take my hands from the controls. After feeling desperate about flying through clouds in a blinding snowstorm, I felt much better seeing that the clouds did not go all the way to the ground. I even flew with a sailplane and a paraglider, so I did not feel so alone. Because of the thunderstorms, I left the Alps early, and had a long crossing over the Italian flats. It seemed to take forever to get to Torino, but in reality the entire flight took less than 5.5 hours. TV crews were waiting, and we saw the story on the national news that night in our hotel, just before a nice dinner with our hosts, the organizers of the World Air Games 2009. We are now preparing to continue down the length of Italy, to Sicily."

  • Eric Raymond
TEAM

Eric Raymond

Eric Raymond's career in flying began at an early age, with model airplanes. Working with Paul Mac Cready, he flew the MPA Bionic Bat. He was invited to fly Gunther Rochelt's human powered Musculair 2 and with Rochelt's help he formulated the concept for the Sunseeker. The Sunseeker went on to break all previous records for solar powered aircraft. Raymond studied aeronautical engineering at University of California San Diego. From 2003 - 2007 he worked with AeroVironment on classified projects building unmanned aircraft for the U.S. military.

Eric Raymond

Irena Raymond

Aviation is a life long passion of Irena's. She was born in the foothills of the Julian Alps, near the Lesce airfield, and spent her childhood visiting the airfield often to watch airplanes fly. She earned her sailplane license when she was only 16, the youngest age allowed in Slovenia. After earning Faculty of Chemistry and Chemical Technology from the University of Ljubljana, Irena worked at Sava Krani engineering rubber compounds for more efficient tires. When Goodyear acquired the firm, Irena worked as a project manager and head of raw materials procurement. In 2005 Irena was selected as the President of the Slovenian Women Pilots Association, an organization dedicated to encouraging women’s participation in aviation in Slovenia and around the World. Irena met Eric Raymond when he was invited to speak at a SWPA event – it was love at first flight! Today Irena is dedicated to the Sunseeker Duo endeavor. She manages the day-to-day operations at Solar Flight.

Irena Raymond

Klaus Savier

A designer, builder, and pilot, Klaus Savier is the president of Light Speed Engineering based in Santa Paula, California. Their main focus is to help develop general aviation as a safe, economical and feasible mode of personal transportation. This includes the production of composite parts aimed to improve aircraft stability, speed, and efficiency as well as electronic ignition conversions that improve engine performance. Klaus is an expert in the field of propeller design. He designs and builds composite propellers for light aircraft and is responsible for the remarkably light folding propeller on the Sunseeker.

Klaus Savier

Bill Watson

A designer and builder with a long history of unique aircraft. Bill Watson is an expert in the field of airship design and construction. He served as the chief construction engineer for the Icarus HPA-1 and Gossamer Albatross human powered aircraft. He also designed and built the human powered airship White Dwarf, which set a distance record for its class with Bryan Allen as pilot and motor. He has consulted extensively with numerous companies including Boeing in the development of their own airship projects.

Bill Watson

Bruce Carmichael

A designer and builder with a long history of unique aircraft. Bill Watson is an expert in the field of airship design and construction. He served as the chief construction engineer for the Icarus HPA-1 and Gossamer Albatross human powered aircraft. He also designed and built the human powered airship White Dwarf, which set a distance record for its class with Bryan Allen as pilot and motor. He has consulted extensively with numerous companies including Boeing in the development of their own airship projects.

Bruce Carmichael

Bryan Allen

The pilot of Gossamer Condor and Gossamer Albatross for the record breaking man powered flights on the late 1970's, Bryan is also a hang glider and ultralight pilot, and helped develop and fly Bill Watson's White Dwarf pedal powered blimp. Bryan is involved with fund raising efforts for the SUNSHIP project, Solar Flight's bid for an around the World solar powered flight. He has a strong interest in airships, and all forms of electric and man powered aircraft.

Bryan Allen

Floyd Fronius

Floyd has been involved with aeronautics for most of his life. He is the machinist who made both tooling and hardware for Sunseeker I and II. His company, Aeolus Machine, has worked on diverse aircraft from the Basic Ultralight Glider series to the Lighthawk microlift sailplane in addition to projects with Solar Flight. Floyd is an experienced pilot with many hours spent flying hang gliders and unique ultralight aircraft including Solar Flight's Edelweiss sailplane. He was also a crewmember for the 2009 European Tour with the Sunseeker II.

Floyd Fronius

Frederik Ottesen

Frederik is an experienced entrepreneur and innovator with a background in mechanical engineering and economics. His insatiable curiosity and passion for adventure took him on a two year circumnavigation of the globe, exposing him to remote corners of the world and testing his resilience. He is one of the founders of LittleSun and serves as Forward thinking, dynamic, and passionate, Frederik works closely alongside Solar Flight's engineers and aviators to develop the company's projects.

Frederik Ottesen

"RC" Dave Freund

David is a designer and builder of light-weight aircraft structures. In addition to working as a shop manager at AeroVironment, Freund worked extensively with Eric Raymond and Bill Watson on the development of the Sunseeker from the initial concept through its flight testing. He was also a member of the team of pilots who flew Alan Cocconi’s solar-powered SoLong UAV for its 48 hour record, the first airplane to complete an autonomous day-night cycle.

"RC" Dave Freund

Roman Susnik

Roman Susnik is an expert glider pilot, who has developed his own electric motors for aircraft. See http://www.enstroj.si/ to see his electric Apis, and other projects. Roman is developing a new 20 kW direct drive motor and controller for the new two seat Sunseeker Duo.

Roman Susnik
CONTACT
General inquiries: info@solar-flight.com
Press and media requests: press@solar-flight.com
tel. +386 40 567 248
Solar Flight Inc.
2450 Montecito Rd.
Ramona, CA 92065
USA