“I maintain the Turing Test for us is if the air traffic controller cannot tell he's talking to an unmanned aircraft,” Facebook's chief flying Wi-Fi router drone man, Martin Gomez, told the Royal Aeronautical Society this morning.
Speaking about Mark Zuckerberg's Internet.org walled-garden wheeze, Gomez explained to the audience, which had gathered for the RAeS's Drones in Daily Life conference, aeronautical details of Facebook's Aquila drones.
Confidently stating that Facebook wants to have “thousands” of solar-powered Aquilas providing internet connectivity across the world, Gomez's audience of professional aviators and regulators was intrigued by his talk.
Following an emerging trend in super-light drones – such as the Ministry of Defence's Zephyr drone – the Aquilas are designed to loiter for days or weeks over a designated patrol zone. Instead of providing overt surveillance, however, Zuckerberg's plan is for these to funnel new Internet subscribers into Facebook's Internet.org/Free Basics capture-register-data mine strategy.
“Their maximum bank angle is 5°,” he said, highlighting how the drones really cannot be operated in windy or gusty conditions. The 5° bank limit is a practical one, allowing a small margin of error, rather than a never-exceed limit. In addition, Facebook's lightweight drones have, according to Gomez, a typical landing speed of just 20 knots – “bicycle speeds”, as he put it.
The Aquila drones typically operate at up to flight level 600, or 60,000ft. Once up at operating altitude, they fly at around 70 knots. For comparison, a Boeing 737 – which has a similar wingspan to the Aquila – typically cruises at around 420 knots, and about 30,000 feet lower.
Bringing Facebook to the poor, huddled masses
The idea behind them is for Facebook's drone fleet to act as a mesh network for internet connectivity backhaul over areas of the planet with very calm weather systems – in other words, the hot deserts of rural Africa, where penetration of wired infrastructure tends to be minimal anywhere outside of major urban population centres.
“Our goal is to be a low cost version of the terrestrial alternatives,” said Gomez. “Once you've installed fibre and protected it against vandalism you're done. We aim to be competitive against that.”
It's going to take an awful lot of these aircraft to provide the sort of always-on connectivity we're used to in the West, with our saturation-level coverage of mobile phone masts and wired backhaul. Will the nature of flying mobile phone masts cause problems?
“You can't be replacing aircraft every week,” said a bullish Gomez, explaining how Facebook's drone fleet will be specified to keep flying for weeks on end. “We're going to have thousands of aircraft flying, around the world.”
Aviation regulators are going to just love this
“Regulators have to be convinced this is a safe thing to do,” said Gomez. On the face of it, he has an uphill task: adding thousands of aircraft in one fell swoop to the existing thousands already using the skies is already giving air traffic control agencies the heebie-jeebies. Operating at 60,000ft has the main benefit of putting Facebook's drone fleet well above almost all conventional aircraft operations, other than the odd US spyplane flight.
Remote ground control stations, where one operator supervises a number of airborne drones, are part of Facebook's concept of operations, according to Gomez: “Ground control allows us to talk and squawk as if we were a manned aircraft.”
Emphasising how the Aquilas “must be able to handle minor system failures” without needing to make an immediate landing, he continued: “I don't think the air traffic controllers of the world want aircaft above them driving around and then saying 'oh I have an emergency, I gotta land now'. Our aircraft must have enough robustness to keep flying until it's safe to land.”
As well as the drones required to provide the network, Gomez foresees a future with redundant airborne drones loitering, cab-rank style, ready to be sent to cover for any drone which has to drop out of the formation. Gomez called this system “in-flight spares” in his slide deck, which initially got your correspondent wondering if Facebook was working on a self-maintaining set of airborne drones.
“Providing Internet service is what this is about,” he said, higlighting how he wants the Aquila fleet to be as robust as possible. “If we can fly for three months surely you can limp along for another day or two” in the event of a systems failure? “There's no such thing as 'land as soon as practical' in a solar powered aeroplane.”
Look, ma – no joysticks!
“Our very first flight was completely automatic. No joystick. I don't think there's any place for a joystick in a 21st century drone,” said Gomez. The concept of operations for the Facebook Aquilas is that the operator at the ground control station sets waypoints for the drones, rather than doing Top Gun impressions with each and every one of them.
While such a system lowers the training requirement for the operator – who then only needs to understand the principles of separation and deconfliction, rather than possessing the extensive and expensive skillset that manned aircraft pilots need – in situations with a waypoint-based control system, where you need to override the control interface, problems can arise, as the British military found out with one of its Watchkeeper drones in 2014.
This may not be such a big a problem for other aviators sharing the skies with Facebook, however. Gomez said that Facebook is looking for “very large” hangars and airfields where they can build ground control stations, as well as places free from “other users for whom we would be a flying obstacle”. This strongly suggests that as well as the drone fleet, Facebook may start building its own airfields around the world. Part of its requirements are that the operating bases are no further away than “a few hundred nautical miles” from the drones' area of operations.
All in all, the concept is intriguing and may well be practical in calm, sunny areas of the world. Whether the idea survives contact with reality remains to be seen. ®