Home - AFV Events - Other AFV Events - Solar Impulse 2 Departure
Solar Impulse 2 is a solar-powered airplane currently in the middle of flying around the world without using any fuel whatsoever. The journey had to be put on hiatus for several months because, after the aircraft arrived in Hawaii last summer, there was not time to perform needed repairs before the autumn days would have gotten too short for the solar cells to accumulate enough energy for overnight flight. That's all behind them now, though; Solar Impulse 2 is back in the air! The team very generously gave me press credentials for the landing at Kalaeloa Airport on the west end of the island of Oahu on July 3, 2015, and they repeated the favor on April 21, 2016 for the departure. Because the aircraft needs calm pre-dawn winds to take off or land, this was a very early morning for everybody; here Bertrand Piccard dons his flight gear at about 2 a.m., including biometric sensors so that Mission Control can monitor his health.
Then he and André Borschberg, with whom he has been alternating piloting duties (and who had flown the record-shattering flight from Nagoya to Hawaii last summer), addressed the assembled Solar Impulse 2 team to thank them for their efforts all along the journey to date and for all the hard work that went into preparing the airplane for the next leg, a three-day flight to Moffett Airfield near Mountain View, California. The plane was then rolled out of the hangar; then the pilots, the aircraft and the team received a Hawaiian blessing and were presented with a hula of farewell (to the tune of "The Prayer"). Nainoa Thompson, who has led the rebirth in Hawaii of the ancient Polynesian skill of wayfinding on the open ocean, presented Bertrand Piccard with a Hawaiian fishhook that had been carved by students of Kamehameha Schools; I saw him pointing into the night sky to indicate the constellation of "Maui's Fishhook," also known as Scorpius.
However, here is the only decent photo I got outside the hangar before dawn; I need to upgrade my DSLR, or at least learn how to crank up the ISO and make it stick, before I shoot any more night activities... As always, there was a crew member holding a stanchion below the wing near each of the outboard motors, to keep the wings from dipping and hitting the ground. I was told that the constraints on safe wind levels are actually most severe during rollout and taxiing; at takeoff or landing the aircraft will be facing into the prevailing wind, and can take advantage of its own streamlining, but as it is turned across the wind while on the ground the risk of a gust catching a wing and causing the plane to tip is greatest.
By 3:45 a.m., the wind had picked up to about 10 knots, with gusts to 14 knots. André Borschberg came back to the press area to tell us the bad news that this exceeded the safe limits, so that the departure would have to be delayed and maybe scrubbed.
The aircraft was rolled back into the hangar for safety, and we waited to see if the winds would die down in time to launch that morning. The takeoff had been scheduled for 5:00 a.m., but the "window" for a delayed departure extended until 6:30 a.m. so there was still some time. The team took the opportunity to allow the public, who had been kept close to the airport fence, to come inside the hangar with the press to get a closer look at the aircraft while we waited (off the left edge of this photo).
Sure enough, by about 5:00 a.m. the winds had died down enough to allow the takeoff to proceed. The press were allowed to walk across the tarmac to a viewpoint nearer the end of the runway, and at about 6:15 a.m. the propellors spun up and the journey resumed! For those of us accustomed to jetliners clawing for airspeed and altitude with engines roaring, the takeoff was surreal. With the huge lift to weight ratio that comes from a wingspan greater than that of a 747 combined with literally over a hundred times lighter weight, the rollout between a standing start and liftoff from the ground was only seconds long, and only took a distance along the runway comparable to a single wingspan! The image above is a frame capture from my video camcorder; click here for a short video (36 seconds, 32.9 MB) showing the takeoff roll. (Maybe if my HTML skills didn't date to 1998, I'd know how to embed the movie in the page rather than just making a link to it... Sorry!) The aircraft then flew the length of the airfield in a very leisurely manner over the course of a minute or more, all the time climbing slowly, with no noise but a quiet, high-pitched whine from the electric motors that somebody remarked "sounded like a Prius."
The delay had worked in our favor, since a 5:00 a.m. takeoff would still have been in the dark, but as it was we were treated to a beautiful backdrop of dawn-backlit clouds and crepuscular rays as Solar Impulse 2 headed northeast before turning south over the ocean and then, after in-flight checkout, heading toward the U.S. mainland. Once again, I wish I was a better photographer; this shot just doesn't do justice to the beauty of the scene.
Well, farewell and aloha to Solar Impulse 2 from Hawaii, and Godspeed, Bertrand Piccard! Many, many thanks to the members of the team with whom I have spoken during my visits, and who were so generous with the press credentials as to let me and my little website in the door! I wish you all the very best as your journey around the world continues.
new 21 April 2016