Aviation Week and Space Technology, the industry’s leading magazine, has been publishing “pilot reports,” on new aircraft for decades. Its pilot report on an aircraft called Centaur was the first in which the pilot doing the test never touched the controls. Centaur is an optionally-piloted aircraft, or OPA.
The reporter conducted the test while sitting in the back seat of the small, twin engine aircraft. Up front sat a person acting as the safety pilot, his arms calmly resting on his lap. Sitting beside him, in what is ordinarily the co-pilot’s seat, was an engineered series of linkages, actuators, and servos. The safety pilot pulled a lever to engage the mechanisms, and they began moving the pilot’s control stick and pressing the rudder pedals. The actuators are double and redundant; if one set fails another will immediately take over. The safety pilot can disengage the mechanism with a single pull of the lever if something goes wrong; unless something goes wrong he does not touch the controls.
In the back seat, the “operator,” commanded the plane through a laptop, using an interface identical to that of the ground control station for an unmanned vehicle. Through the screen, he could change altitude, fly to waypoints, takeoff or land. Pushing the “launch” button began an autonomous takeoff. The computer held the brakes, pushed the throttles forward, checked the engines and instruments, and released the brakes for the takeoff roll. The plane accelerated, took to the air, and began to climb out on a semi-autonomous flight.
As an OPA, this aircraft can fly in a normal mode under pilot control, as a certified aircraft as though it was fresh from the factory. But it can be flown in this semi-automated mode, as the reporter issued high-level commands through the laptop in the back seat. Or it can be flown unmanned, with the same computer interface operating on the ground through a radio link. It is called “Centaur” after the mythical half-human half-horse creature.
Engineers at Aurora made Centaur by converting a commercially-available aircraft, a Diamond DA-42 to this OPA mode. They added the mechanism in the front seat, a host of independent electronics, and digitized the flight manuals and emergency procedures into computer algorithms.
Unmanned aircraft are currently mostly illegal in the US national airspace, but Centaur is certified by the FAA to fly in its unmanned mode if a safety pilot is aboard. Hence the aircraft can help develop sensors, algorithms, and procedures for unmanned systems. It has been flown with a pilot aboard to Alaska, where it has permits to operate in an unmanned mode to collect data for climate research.
Centaur is a transitional technology, suitable for flight testing and engineering development while regulations and techniques are worked out. It contains within it, however, the seeds of a new way of piloting, for eventually, even in US airspace, the front-seat safety pilot’s job can be transformed to one operating through the laptop interface.
Will the Future Include Human Pilots Inside the Cockpit?
Are we moving into a future of airliners without pilots? Probably not for the foreseeable future, but Centaur shows us how much of the technology exists today. A DARPA program called ALIAS, seeks to extend the OPA idea to any aircraft by building a general-purpose robot to sit in the right seat. In a technical sense, the automation to taxi an airliner, command a takeoff, follow a route and autoland is all well proven. The unmanned aircraft problem appears to have been solved — but only when artificially divorced from its human context.
But many examples from automation and robotics have taught us that fully autonomous operation is the lesser problem. We can say that the technology exists today, but for the innovation to have a social importance and contribute to human welfare requires not only the machines but the social, policy, and economic systems to situate these machines into human life and to enhance our practices and our experiences, a much more open problem.
Airliners need to be safety certified so they don’t fall on people. They need to provide not only statistical safety for passengers, but also the experience of safety. They need to operate not only in every emergency we can think of, but in nearly all of the emergencies we can’t think of. This is why, when placed within human settings of reliability, risk, liability and trust, the unmanned aircraft problem, like the driverless car problem, has not been solved. Building the trust in such systems will require years of demonstrations, operations, and smart engineering to prove reliability and work within human environments.
David A. Mindell is a professor at MIT and founder and CEO of Humatics, which is developing technologies for trusted, transparent autonomy situated within human systems. He adapted this article from his book, Our Robots, Ourselves: Robotics and the Myths of Autonomy (Viking/Penguin 2015).