Facebook's Composite Aircraft Weighs Only as Much as a Piano

Facebook announced the successful completion of the second test flight of Aquila, its solar-powered unmanned aircraft designed to provide internet to remote regions of the world. The aircraft's first test flight last year ended with a structural failure that affected landing. However, this time Aquila landed "perfectly," according to Martin Luiz Gomez, Director of Facebook's Aviation Platforms. As Facebook founder and CEO Mark Zuckerberg disclosed last year, Aquila has a wing area wider than a Boeing 737, but must be as lightweight as possible to stay airborne for extended periods. In a blog post published in 2016, Zuckerberg stated: "For this reason, the aircraft fuselage is made of carbon fiber composite material; everything weighs less than 500 kg, and the entire aircraft actually weighs the same as a grand piano." "We need to continue making it lighter." Gomez noted that Aquila's second test flight incorporated lessons Facebook learned from the first flight. Before the second flight, the company made a number of modifications to Aquila, including adding "spoilers" to the wings to reduce air resistance and decrease lift during the landing phase. The Aquila team also integrated hundreds of sensors to gather new data, modified the autopilot software, added newly integrated radios, achieved a smooth surface finish on the airframe, and installed a horizontal propeller-stopping mechanism to support a successful landing. Gomez adds that Aquila does not have landing gear in the conventional sense. The aircraft lands on Kevlar skids attached to the bottom of the engine nacelles. The second test flight lasted a total of one hour and 46 minutes. Looking ahead, Facebook wants to break the record for the longest unmanned aircraft flight. Zuckerberg envisions multiple Aquila aircraft communicating with each other via lasers and, in a way never attempted before, remaining airborne for months at 60,000 feet altitude.

Source: https://code.facebook.com/posts/1186557928107489/ reviewing-aquila-s-first-full-scale-test-flight/