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Solar Powered Plane Completes Cross-Country Flight
An anonymous reader writes "The Solar Impulse, a solar powered aircraft, landed at New York's John F. Kennedy International Airport completing its historic cross-country flight. From the article: 'The flight plan for the revolutionary plane, powered by some 11,000 solar cells on its oversized wings, had called for it to pass the Statue of Liberty before landing early Sunday at New York. But an unexpected tear discovered on the left wing of the aircraft Saturday afternoon forced officials to scuttle the fly-by and proceed directly to JFK for a landing three hours earlier than scheduled. Pilot Andre Borschberg trumpeted the milestone of a plane capable of flying during the day and night, powered by solar energy, crossing the U.S. without the use of fuel.'"
But is this something that we can convert into a practical design for transporting goods or people cross country or is it just a gimmicky air craft that while nifty will likely never see any wide scale use beyond hobbyists, a la ultralights.
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Pilot Andre Borschberg trumpeted the milestone of a plane capable of flying during the day and night, powered by solar energy, crossing the U.S. from West to East without the use of fuel.
Now let's see how they get back from NYC to SF without the use of fuel.
Although I realize this is probably a big achievement, I was a little disappointed to find out that this wasn't done in a single flight, but rather many smaller trips with stops in between. I can't believe this wasn't mentioned in the summary, Makes the news sound much more spectacular than it actually was. I really don't think you can count this as a cross-country flight when it had to make multiple stops along the way. Really, it's just a series of short flights in the same direction. It's not like when somebody runs across the country, and we just all assume it wasn't non-stop, with a plane we kind of assume that there wasn't any stops.
Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
I don't mean to be a whiny spoilsport, but with all the congestion in the airspace around NYC, why did they pick JFK to land a slow-moving and delicate aircraft?
There are numerous airports at the periphery that are significantly less busy, like Stewart International or Islip/McArthur that could have been used for this event. The need to avoid wake turbulence and make sufficient room in the pattern to accommodate such an aircraft had to be a pain to manage.
Regardless, excellent achievement in a cool aircraft.
According to the Bronze Age Greek calendar, yeah, that sounds about right.
Ezekiel 23:20
It left Phoenix Arizona May 22, 2013 and arrived at JFK 46 days later with a straight line distance of 2200 miles . That would be 47 miles per day. Sure there were a few stopovers but that is a very low daily mileage. Even if they flew one day in ten that is still only 470 miles per day.
I have a few questions for the makers of Solar Impulse;
1. How long does it stay on the ground charging the solar cells?
2. How often do they actually use the electric motor?
3. What percentage of time are they utilizing natural lift such as thermals and ridge lift?
I looked at their
web site
. It is a great PR site that give little or no technical information of the flight and how they are actually done. I would like to see the following;
1. Altitude logs for the flights,
2. Electric motor usage charts.
3. Battery charge level charts,
4. Exact track plots of the flights.
I bet we would have a very different picture of Solar Impulse if they let this information was let out.
It is my contention that Solar Impulse is a sailplane with enough electrical power to get to altitude and move between natural sources of lift. Conventional sailplanes can do almost everything that Solar Impulse does. The exception being taking off though there are some powered sailplanes that do that too.
Lets do a speed test to find the limits of the technology rather than a leisurely promotion trip. I am not impressed.
You are right. There is a fundamental dishonesty and up-selling of this story which in every iteration on the wire conveys an impression of continuous flight. In fact, the link on Google's home page led me to detail that seemed that way. So what is it with the media, press, and politics these days that insists on perpetually bending the truth and making false claims?
Little lies are total bullshit.
*rubs head* alright.... while I can appreciate that it's a solar-powered, electric plane, this thing has really only served to prove one very important point - we are no where NEAR ready to make solar powered planes yet.
Solar cells are just not efficient enough to make this a viable means of powered flight. The proof is in the stats - 11,628 cells are only enough to provide the plane power to lift itself and a pilot. And that's with a wingspan of 208 feet. It has no on-board luxuries of any kind... including a toilet, and because it's maximum speed is 43mph (often less when dealing with air currents) that makes for a rather uncomfortable ride that lasts a long, long time.
Even though you can drive somewhere faster than you can get there on this thing, the one thing it does at least prove is that a solar plane is possible. Just barely with current technology, but possible. As cell efficiency, weight, and materials continue to improve, so will the solar planes that come from it. Until then... we're stuck with the gas-guzzling current batch of technology. :/
This article is about a night flight dine by Solar Impulse. Though they do not say it, I bet they started with 100% battery power. Here are a few interesting excerpts from the article.
. He remained at this altitude until about noon, flying backwards and forwards along the Jura mountain chain.
I am a glider pilot and this indicates that he is using ridge lift or mountain wave to stay alloft and/or gain altitude. Both are standard sailplane tactics.
After 14 ½ hours of flying, at 9:30pm, André Borschberg switched off the solar generator
Around midnight, the aircraft was at 4’500 feet, slightly less than 1’500 m, the altitude it needed to maintain until sunrise.
At 5:46am, on July 8, HB-SIA became the first solar-powered airplane to successfully complete a night flight.
By validating the fact that the HB-SIA had returned with a 54% charge level in its batteries,
So the aircraft consumed 46% of it's charge in about 5 hours and 46 minutes. Night was about 8 hours long. So they have proven that under controlled conditions with a very long day and a very short night the aircraft can fly overnight. Considering the sailplane record is 56 hours 15 Minutes, I am not impressed. It is still a toy with no practical application.
How much faster is this than a solar dirigible? What kind of load can it carry?
I'm happy this worked, and it should be pursued, but it seems to me lightweight bags of gas are particularly good at remaining aloft and have a surface area that ought to be very compatible with some electric engines. And since the lift isn't totally depending on the turbines, you could probably move cargo cheaply too.
Now make it 800,000 lbs of plane, pax, and luggage, and do it in 5 hours or less east to west.
Then you'll have something.
By your rather broad interpretation, nearly everything is fuel, including you.
One commenter mentioned the "fundamental dishonesty" of many of the stories on Solar Impulse. Hah. Even the Solar Impulse site itself acknowledges that a trans-USA flight in a series of hops was done by a previous airplane, Sunseeker. The year? 1990. Here's a photo of the plane: http://www.inhabitat.com/wp-content/uploads/sunseeker_solar_main.jpg
Wikipedia shows where Solar Impulse fits in the history of electric and solar-powered airplanes (it's pretty far down the list): http://en.wikipedia.org/wiki/Solar-powered_airplane
I have been astonished that so many "news" organizations were not all over the REAL story: latecomers trying to puff themselves up as "pioneers" and "innovators", when all of the pioneering and innovating in solar-powered airplanes was done decades previously. "Solar Challenger", anyone?
This is really nice and cool. And saying I few at 45mph across the US would nice. What does this actually accomplish? Can we actually move products across the country or people or things or something?
-- A computer without Windoze is like a choclate cake without mustard
The plane had to support the weight of the batteries and the solar cells. It had to be able to lift off and travel across the country so it could not rely on ridge lift for most sections of the flight. This same plane made it over night, all be it with the help of sailplane flying techniques. However, it is not, in fact, designed to be a sailplane nor does if function solely as one.
Define "Fuel". You are playing word games to make fun of others, when it is you who is wrong.
Learn to love Alaska
The U.S. is a small country to fly across. Try flying across Canada! From the edge of Yukon to edge of Newfoundland. About twice the distance, and probably a lot less light to use power due to the higher latitude. This solar plane needs to be tested in all sorts of environments and I'm sure we can provide some. From cold, snowy, rainy, humid, and even hot on some days.
You cannot defy the laws of physics and they tell me that even with weightless 100% efficiency solar cells that cover a huge blimp you might barely able to drive the thing. Why not store the energy that can be collected with ground based solar cells (where weight doesn't count and efficiency in terms of power vs. surface not that much) in synthesized fuel (say, methanol) and use it in a rather traditional plane ???
Unpressurized cabin or no, the rated service ceiling is 8500 m, and it is capable of reaching 12,000 m. Sailplane cockpits are not pressurized either, but the altitude record for sailplanes is 15,460 m. Jet streams can be found as low as 7000 m, though they are usually at least 10,000 m.
The thing that boggled my mind about this plane was, why build a plane with a basically unlimited endurance, and then burden it with a pilot, who can't possibly last very long? The plane can only travel 1700 km per 24 hours.
The thing that boggled my mind about this plane was, why build a plane with a basically unlimited endurance, and then burden it with a pilot, who can't possibly last very long? The plane can only travel 1700 km per 24 hours.
Rough guess? Weight and complexity.
I don't have the plans in front of me, but I'd wager that there wasn't very much in terms of 'controls' of this aircraft. It is very likely mechanically controlled rather than fly-by-wire or even electrically assisted. Basically a system of pulleys and wires. It may not seem futuristic, but it is light, simple, and well understood.
To fly the aircraft by computer, every single control surface would have to be hooked up to an electric motor. You wouldn't save weight there as control and power wiring would have to be run through the fuselage and wings. The wire would weigh at least as much as the wire used to mechanically control the surfaces. The combined weight of the motors would probably get close to the weight of the pilot. Your flight control system would require feedback from the motors and sensors, and the FCS in itself would be rather weighty, relatively speaking.
All these electrical devices require power to operate, and as you might guess, the prime, number one, do not waste, absolute critical resource of this aircraft is power. Every watt is precious, and navigation/flight calculation is not computationally inexpensive.
You might try to save some weight by having the aircraft be piloted remotely, but that just introduces another weighty, power consuming component: the radios needed to receive commands and transmit position/feedback/video/etc. I'd wager that there are few commercial radios available today which could handle the data requirements of a drone aircraft. (not my area of expertise, but most voice radios aren't rated for much more than 20% transmit duty cycles.) Even so, you don't want to transmit more than the absolute minimum in order to minimize energy consumption. A drone aircraft radio must transmit more often than a regular ATC voice radio. (minimumATC voice + minimumDroneResponse will always be more than just minimumATC voice)
Do you trust your design? That would be an expensive and public crash if your flight control system had a bug that didn't consider that your air pressure sensor was clogged (see B-2 crash in Guam)
Then comes the regulatory hurdles. If you designed your own flight control system, you are going to be hard pressed to get the FAA to approve your aircraft for flight anytime soon. Are they even approving civilian drones yet? Let alone autonomous systems.
So basically it boils down to this:
A pilot is a well understood control system as it pertains to aircraft and regulatory approval. The pilot and his gear will weigh less than 100kg. Included in that 100kg is everything you need to control an aircraft for a significant chunk of the aircraft's endurance of 36 hours. The cost is known, the design is proven, the regulatory approval process is effectively nil.
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