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Solar plane completes maiden intercontinental trip
SALE, Morocco |
SALE, Morocco (Reuters) - A solar energy plane landed in Morocco on Tuesday, completing the world's first intercontinental flight powered by the sun to show the potential for pollution-free air travel.
The Solar Impulse took off from Madrid at 0322 GMT ( 11:22 p.m.) on Tuesday and landed at Rabat's International airport after a 19-hour flight.
Shortly before Swiss pilot Bertrand Piccard landed in Rabat's airport, the project co-founder and pilot Andre Borschberg said the aircraft has proved its sustainability.
"The aircraft can now fly day and night. It's quite a show ... It's a technology we can trust," he told reporters.
Pilot Piccard descended from the plane, smiling as he was greeted by Borshberg and Mustafa Bakkoury, the head of Morocco's solar energy agency.
The Solar Impulse project began in 2003 with a 10-year budget of 90 million euros ($112.18 million) and has involved engineers from Swiss lift maker Schindler and research aid from Belgian chemicals group Solvay.
On Tuesday, the aircraft crossed the Gibraltar Strait separating Africa and Europe at one of its narrowest points. The flight is crucial for the project's developers because it would help improve the organization of a world tour planned in 2013.
The plane, which requires 12,000 solar cells, embarked on its first flight in April 2010 and completed a 26-hour flight, a record flying time for a solar powered aircraft, three months later.
It made its first international flight last month when it completed a 13-hour flight from the western Swiss town of Payern to Brussels.
With an average flying speed of 70 km/h (44 mph), Solar Impulse is not an immediate threat to commercial jets, which can easily cruise at more than 10 times the speed. A flight from Madrid to Rabat can take a little more than an hour.
Project leaders acknowledged it had been a major challenge to fit a slow-flying plane into the commercial air traffic system.
(Reporting By Souhail Karam; Editing by Vicki Allen)
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It uses energy (energy source irrelevant here) to get off the ground. Only when it is airborne at a certain cruising speed and altitude does it switch to on-board generated propulsion.
How else do you think the plane would launch? It is one thing to maintain speed but quite another to accelerate from speed zero to launch speed. How a bout night launches and night flights? And what if it’s cloudy? Such a plane cannot reach above-cloud altitude even if it
uses on-board engines just for starting. Launching takes the highest level of thrust which means power which means energy. To not only get the plane of the ground but above the cloud ceiling it would have to get up to 20,000 feet in some instances. That calls for a big (heavy) engine that would have to run for a fairly long time. Fuel weighs a lot. The time ratio of engine-on time to engine-off time would only be attractive at very long distance flights such as transatlantic or transpacific flights. At the quoted speeds those flights could take two days or more. For shorter distances the engine-off time would be quite short and make
the whole thing impractical.
The laws of physics are not going to change in a hundred or two-hundred years. They are eternal. Those laws of physics are not on the side of the optimists who blindly believe that science will solve every problem. To get even a relatively small commercial 100-seater airborne will take a fairly heavy on-board engine to reach launch speed and/or it will require a very, very long runway.
To create the glide ratio necessary for such a plane to be relatively safe in commercial applications the relationship of the size and weight of the fuselage to the wing size (to accommodate a sufficient number of photovoltaic cells) would be grotesque.
There are plenty of other issues such as cargo space and weight, limited altitude (as the air gets thinner, say, at 15,000 ft and above, the plane finds it harder and harder to stay aloft) Low altitude flying brings with it the associated exposure to much more turbulent air.
Flying across the Strait of Gibraltar is equivalent to a short commuter flight. I have taken the ferry across to Tangiers and I know of what I speak. True, you travel to another continent (Africa) but it’s just a hop and a skip. “Transcontinental” is hype and a gimmick.
I want to see them fly the plane from Salt Lake to Denver, across the Rockies. Lastly, the longer the wings the greater the vulnerability to sheer factor in turbulence upon launching and landing. strafing the ground with a wing tip usually spells disaster.
We don’t know what we don’t know. I don’t have a crystal ball and don’t want to sound cocky, like a know-it all. I don’t fly or design planes. But using just a few minutes to think this through, common sense forced me to draw above conclusions. I may be completely wrong. You decide.
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