It is a familiar part of flying. As you taxi towards the runway, a crackly voice is heard over the intercom. The pilot’s brief summary of the route, flight time, and weather conditions are designed to inform but also to reassure. The familiar refrain tells passengers the plane is in safe, human hands and they can relax and enjoy the flight.
But the phrase “this is your captain speaking” may soon become a thing of the past, thanks to a new generation of robotic, passenger aircraft that will take to the skies by themselves.
“We believe that unmanned aircraft are the next big transformation in the aviation industry,” says Doug Davis, director of the unmanned aircraft programme at New Mexico State University.
Of course, the military already know this. Automatic landing systems have been used for years to help pilots drop F-18 aircraft on to the narrow landing strips on top of aircraft carriers. Then there is the rise of drone warfare. These planes are still flown remotely by pilots on the ground, but most have the capability to follow a predefined flight path and even land themselves if they get into serious trouble or the link between the ground is broken. The next generation, such as the US Navy’s X-47B, will be even more advanced, with onboard intelligence that will allow it to adapt its course and fly with only minimal input from a pilot.
The path to this automated future began almost 100 years ago with the introduction of the first autopilot. These systems – designed to keep a plane on a steady, pre-programmed heading and altitude – introduced the first automation into the cockpit, allowing the pilot to step away from the controls.
Over the next century, this trend gathered pace, packing modern aircraft with sophisticated electronics, which often relegate the human to a passive observer. In fact, in some modern aircraft the pilot is only needed to taxi the aircraft to the runway. Everything else from take-off to landing can be automated.
“The technology is here,” says Missy Cummings, an ex military pilot who is now associate professor at the Massachusetts Institute of Technology’s department of Aeronautics and Astronautics.
She points to the rise of so-called fly-by-wire technology, which has replaced the mechanical link between the pilot and the plane’s engines and control surfaces with computer signals sent down a copper wire.
“Any fly-by-wire plane can be an [Unmanned Aerial Vehicle],” she explains. “The controls are digital, not analogue, everything is done electronically so you don’t need a person in there to push a hydraulic actuator.”
To prove the point, technology company BAE Systems recently flew a converted Jetstream aircraft – known as “The Flying Test Bed” – with no pilot in UK air space. The trial flights did have people on board, allowing a human to take control in an emergency. But, for the large part, it flew itself.
But while it is one thing to conduct test flights with pilots on hand in case of an emergency, it is quite another to pack 350 passengers on to plane and send them on their way across the Atlantic with no one at the front. As a result, autonomous flight technology is likely to be adopted in stages.
Already, we are in an era when planes are flown by just two pilots, down for a peak of around five a few decades ago. In the near future increasing automation will mean that number drops to one. And then the next stage could see planes piloted from the ground, like military and scientific craft.
The final stage will be to remove the human control altogether. To do, that planes will have to be capable of complex decision making. “The plane has to know its position, its current state, where it’s going, what the winds are, its orientation, that kind of thing,” says Davis. “You’re going to need continuous health monitors to know when your systems are degrading. And it’s not only avoiding collisions, but it’s also not causing collisions.” In other words, a plane will need to be aware of its surroundings and be able to plot a new path that is not disruptive to other users of the skies - intelligence known as “sense and avoid”.
This is currently the pilot’s job, who can look at radar and even glance out of the window. But machine vision is not easy and requires video-cameras, sensors and powerful computers to interpret what they were seeing in real time.
But progress is being made in this area. You only need to look at the rise of the autonomous car to see that computers are getting better and better at viewing an interpreting their surroundings.
Current UAVs – even those controlled by a pilot – also already have some sense-and-avoid capability, to account for the tiny lag between an operator sending an instruction and it being delivered to a plane. Professor Cummings believes that capability is only going to get bigger. . “In the aircraft that we have today, there is a lot of decision making on the ground about what to do next. In autonomous aircraft, much of the decision making is made onboard, by the aircraft.”
Dr John Tracey, chief technology officer at Boeing, agrees. He sees no need for decisions to always be made on the ground by Air traffic Control.
“The current Air Traffic Management System (ATM) we have is based on 1950s technology,” he told me at a recent technology summit in Silicon Valley. “It’s based on the assumption that the airplane does not know where it is, cannot figure out how to go from where it is to where is needs to be, that is doesn’t know where anyone else is, and that the purpose of ATM is to keep planes separated. Those are all false.”
He believes the current system based on ground based radar, and a controller who uses voice commands to “say to the pilot ‘turn left, turn right, go up, go down,’” is very inefficient.
“The new planes that we deliver already have the capabilities built into them to use GPS satellites, to allow them to fly on the most optimum flight path,” Dr Tracy says.
The next step would be to allow aircraft to make more decisions for themselves and respond to other planes and weather patterns by themselves.
Safety in numbers
Of course, some communication with the aircraft will still be vital – certainly in the early days - and planes will have to be able to communicate with each other. And, this could be a major challenge, says Doug Davis as more of the airwaves are assigned to other uses such as mobile phone networks. “One of the underbellies of unmanned aircraft technology is available frequency spectrum,” he says. “If we don’t have enough spectrum for command and control it is going to cause a lot of problems for our bandwidth needs for the future.”
However, plane makers clearly believe the problem can be cracked. Aircraft manufacturer Airbus recently released its view of the future of aviation towards 2050 and beyond, and one of the things it stressed was the benefit of planes that can fly themselves. In an extreme proposal, it suggests passenger planes might fly together in flocks, which can result in huge energy savings. They would keep in sync by constantly monitoring their position relative to one another.
While everyone seems confident that the technical challenges of such visions can be overcome, there is perhaps one more significant hurdle to overcome - persuading the general public that a plane without a pilot is safe.
On that point, Professor Cummings says the data is increasingly in favour of unmanned systems. “About three years ago UAVs became safer than general aviation, meaning that more general aviation planes are crashing than UAVs, per 100,000 flight hours,” she says. “So UAVs are actually safer than a weekend pilot, flying a small plane.”
That may not be a huge surprise. But what is perhaps more telling is that last year UAVs became safer than highly trained military fighters and bombers. “I knew that was coming, and it’s one of the reasons I jumped into this field and left commercial piloting and military piloting behind,” says Prof Cummings
Yet data may not be enough, she acknowledges. “The reason that you like a pilot in the plane is because ultimately he or she shares the same fate that you do,” she says. “So if the plane is about to go down, you feel better knowing that there is a human in the front seat doing everything that they can to save their own life.”