Last we heard from the U.K.'s high altitude Zephyr glider, it was unofficially breaking the record for longest unmanned flight. That was back in 2007, when the record was a paltry 30 hours, and the Zephyr was able to manage a 54 hour flight, thanks to its solar powered batteries. On Friday, the Zephyr flew that and them some when it completed an 84-hour flight without issue. Military types are no doubt licking their lips at the news, as the plane was designed to support troops in the field with continuous surveillance and communication support from its perch on high at 60,000 ft. [Telegraph]
It's amazing how much this looks like a giant r/c plane!
The wing construction is straight out of r/c hobby planes, and the shape is the same as a lot of r/c gliders.
Of course, then again it's not surprising as the principles are the same: low weight, high glide angle, good strength to weight ratio, etc.