Fourteen hours and four minutes after departing Cincinnati, Solar Impulse pilot Bertrand Piccard touched down at Washington Dulles International Airport. He arrived at 12:15 a.m. Eastern June 16. It was the second leg of what originally had been one planned hop from St. Louis to Washington, D.C. However, Solar Impulse's other pilot, André Borschberg, had to stop in Cincinnati on the way because of a strong thunderstorm system that pushed through the Midwest and mid-Atlantic June 12 and 13. Because of needed rest between the long flight legs, Borschberg handed the aircraft over to Piccard to fly to Dulles.
Borschberg took some time during his flight June 14 while at 10,000 feet msl near Indianapolis to give AOPA Live Executive Producer Warren Morningstar a live interview.
Like any pilot, Borschberg’s talk quickly turned to the weather. “The weather systems are difficult,” he said, adding that they have “a lot of energy.”
Much of the solar-powered flight has been plagued with severe weather. Departing May 3 from San Francisco, Piccard flew to Phoenix; the second flight leg was to Dallas/Fort Worth. The Solar Impulse team—its pilots in the United States and control center staff in Switzerland—had to make decisions about the continued flight after a tornado that ripped through the Midwest damaged the hangar that was to house the aircraft in St. Louis. The team ultimately continued to St. Louis, where the aircraft was housed in a portable hangar.
Weighing less than a car and having a wingspan similar to that of an Airbus A340, the Solar Impulse isn’t the easiest aircraft to fly; however on June 14, Borschberg told a reporter that he was flying with just two fingers. The Solar Impulse does not have an autopilot.
Borschberg said he took a structured approach to learning to fly the aircraft, starting first in a simulator. The aircraft requires only very slight banks, he said, about two degrees. The aircraft’s reaction to inputs is slow, and it has low wing loading. Close to the ground, the aircraft can be difficult to control, which is why the pilots wait to land until the middle of the night and take off before dawn—before there are thermals.
While Borschberg typically flies higher than 10,000 feet msl, strong winds at higher altitudes prevented him from climbing June 14, else he would not be able to reach Cincinnati.
The solar panels had fully charged the Solar Impulse’s batteries, according to an update at 2 p.m. Eastern. Earlier in the day, at 9 a.m. Eastern, battery power was at 59 percent, according to the Solar Impulse website.
“I’m physically alone but with the control center just next to me as copilots,” Borschberg said of his mission controllers in Switzerland.
One of the highlights of flying in the United States, Borschberg said, is the people. “Everywhere we land … the people we met was unbelievable,” he said.
Borschberg also commended the FAA for working with him and the flight crew. He acknowledged that it isn’t easy to fit the Solar Impulse into the National Airspace System at the busy major cities he’s flown into because of the aircraft’s low speed. At 5,000 feet msl, Borschberg had a ground speed of 25 knots and at 10,000 feet msl, 39 knots. The aircraft takes off at 27 mph, according to the website.
“The spirit we have seen in this country is really great,” Borschberg said, explaining visitors’ interest in the aircraft’s innovation.
While Borschberg acknowledged that 100 percent solar-powered airplanes are not normal in day-to-day aviation, he said some of the ideas behind the Solar Impulse could find its way into general aviation aircraft. “I will see the first [general aviation] electric propulsion coming soon,” he predicted. A plus with that: Fewer noise complaints at airports. “This airplane doesn’t make any noise,” he said.
Solar Impulse has one more U.S. destination left on its schedule: In early July, the aircraft will fly to New York City.