120 Hour Solar Powered Flight

[Ben]

This Swiss pilot is going to attempt a 120 hour flight from China to Hawaii as one of his legs flying a solar powered aircraft around the world. Previous legs have maxed at 20 hours. I didn't see any references to test flights, but one would hope that he did some test flights circling areas where he could easily do an emergency landing to test the endurance of the power system.

The aircraft looks like it would have decent glider properties, but he's still going to be over the middle of the ocean, and will be dropping down to 3000 feet at night (I assume to keep the batteries warmer), so he drastically reduces his time and options for emergency maneuvers.

http://www.aol.com/article/2015/05/03/pilot-to-fly-solar-plane-across-pacific-for-5-days-5-nights/21179233/?ncid=txtlnkusaolp00000058

[KD5NRH]

Interesting, but it looks like he's averaging under 45mph ground speed.  If someone could make even a daytime-only version of this that could hit, say, 100mph, I could see it being a popular long weekend rental; no fuel costs for someone here to head down to the coast without 6-7 hours of traffic, for example.  Obviously winds matter a lot, but the extra airspeed would make it safer anyway.

[MechAg94]

He plans to take periods of rest of 20 minutes up to eight times a day, but said he doesn't know if the weather or turbulence will let him. Borschberg said the plane has a "virtual co-pilot" that is a stabilization tool. It will sound an alarm to wake him if the aircraft does something unplanned.

When he says "virtual co-pilot", does that mean remote or just a bunch of alarms. 
I was wondering how he was going to handle 120 hours.  Hope he doesn't oversleep.

[KD5NRH]

When he says "virtual co-pilot", does that mean remote or just a bunch of alarms.

Most likely altitude hold and wing leveler, plus a GPS with audible off-course alert.  Not overly fancy, but enough to make sure he stays in the air and going more or less the right direction.

[230RN]

Best of luck to him.

A little background on one of the most inspiring efforts (but unmanned) in this area of aeronautics:

http://en.wikipedia.org/wiki/NASA_Helios

http://images.info.com/search?qcat=images&r_cop=xxx&qkw=helios+uav

Interesting on the control surfaces etc. on the Helios:

The only flight control surfaces used on the Helios Prototype are 72 trailing-edge elevators that provide pitch control. Spanning the entire wing, they are operated by tiny servomotors linked to the aircraft's flight control computer. To turn the aircraft in flight, yaw control is applied by applying differential power on the motors — speeding up the motors on one outer wing panel while slowing down motors on the other outer panel. A major test during the initial flight series was the evaluation of differential motor power as a means of pitch control. During normal cruise the outer wing panels of Helios are arched upward and give the aircraft the shape of a shallow crescent when viewed from the front or rear. This configuration places the motors on the outer wing panels higher than the motors on the center panels. Speeding up the outer-panel motors caused the aircraft to pitch down and begin a descent. Conversely, applying additional power to the motors in the center panels caused Helios to pitch up and begin climbing.

Bolding mine.

Pisssed me off that they attempted to fly the damned thing in "extremely marginal" conditions. They shoulda got the message when they had to delay takeoff because the wind had shifted to an unexpected direction. <snarl>

Well, we gotta keep to the testing schedule, right?

Terry

[KD5NRH]

Pisssed me off that they attempted to fly the damned thing in "extremely marginal" conditions.

It's a NASA tradition.