The Aquila internet drone was recently able to complete a test flight in its second attempt. Details of the test flight were shared on Thursday though the Facebook drone had taken the flight more than a month ago.
“The aircraft flew for 1 hour and 46 minutes, and landed perfectly on our prepared landing site,” wrote Martin Luis Gomez in an online posting on Facebook’s engineering blog.
In the first test flight the Facebook drone had a structural failure leading to a crash in Arizona. This led to the National Transport Safety Board to conduct investigations over the incident. To increase the chances of success for the test flight, the team behind the Aquila drone modified the aircraft in response to the lessons that they gleaned from the initial flight. Spoilers were added to the wings with a view to increasing the drag and thereby reducing lift when landing.
Other modifications included adding more sensors which would help in gathering data, installing a mechanism for stopping the propeller in order to ensure that landings were successful and giving the drone a smoother finish. The autopilot software of the drone was also modified.
With the landing in the first test flight having been the weak link, the Facebook drone team thoroughly prepped the landing ground by having level gravel that was six inches deep spread over a circle measuring 500 feet.
According to Gomez, Aquila is almost fully autonomous with regards to flying except when there has to be a manual intervention. This is, for instance, when it has to be lined up in the direction of the wind. Prior to Aquila landing in the second test flight, the crew uploaded a landing plan which was based on the direction of the wind. This also helped in making the second test flight a success.
Power of the sun
Just before it landed, the autopilot software of Aquila killed the propellers according to plan. This was with the intention of locking them in a position where they would not be in danger of getting damaged as the drone touched down. While the landing went according to the laid-out plan, the Facebook drone got dinged by the gravel. This was minor though.
Facebook has indicated that the drone is designed to stay in the air for a couple of months providing internet access to underserved parts of the world. The drone is powered by the sun.