Solar Powered Plane Completes Cross-Country Flight 105
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.'"
Re:Solar Flight, great and all . . . (Score:4, Interesting)
Could also be useful for spying - cloud cover can scupper satellites.
So you send a solar-powered drone to look below the cloud cover? Sounds logical.
Toy (Score:5, Interesting)
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.
Over Night Flight (Score:5, Interesting)
This article [solarimpulse.com] 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 [wikipedia.org] or mountain wave [wikipedia.org] 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.